Data from the

NATIONAL SURVEY OF FAMILY GROWTH

Trends in Breast Feeding

Among American Mothers

Statistics based on data coIlectedin 1973 arepresented on breast

feeding of first- and second-born babies. The percentages of mothers who breast fed and who breast fed for 3 months or more are

distributed by year of the mother’s birth and year of the baby’s

birth. These distributions are shown separately for women classified

by race or ethnicity, geographic region, and various socioeconomic

variables.

DHEW Publication No. (PHS) 79-1979

Series 23

Number 3

DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

Public Health Service

Office of Health Research, Statistics, and Technology

National Center for Health Statistics

Hyattsville, Md. November 1979
Library of Congress Cataloging in Publication Data

Hirschman, Charles

United States. Office of the Assistant Secretary for Health.

Trends in breast feeding among American mothers.

(Vital and health statistics : Series 23, Data from National Survey of Family Growth ;

no. 3) (I) HEW publication; (PHS) 79-1979)

1. Breast feeding–United States–Statistics. 2. klothers-United States–Statistics.

I. Hendcrshot, Gerry E., joint author. II. Title. III. Series: United States. National Center

for Health Statistics. Vital and health statistics : Series 23, Data from the National Survey

of Family Growth ; no. 3. [DNLM: 1. Breast feeding–LTnited States–Statistics. W2 A

lN148vwno.3]

RJ216.U48 1979 649’.3 79-11092

ISBN O-8406 -0159-X

..
NATIONAL CENTER FOR HEALTH STATISTICS

DOROTHY P. RICE, Director

ROBERT A. ISRAEL, Deputy Director

JACOB J. FELDMAN, Ph.D., Associate Director for Ana@is

GAIL F. FISHER, Ph.D., Associate Director for the Cooperative Health Statistics System

ROBERT A, ISRAEL, Acting Associate Director for Data Systems

ROBERT M. THORNER, SC.D., Acting Associate Director for Interriatiowd Stati.$tics

ROBERT C. HUBER, Associute Director for Management

MONROE G. SIRKEN, Ph.D., Associate Directorfor Mathemutica2 Statistics

PETER L. HURLEY, Associate Director for Operations

JAMES M. ROBEY, Ph.D., Associate Director for Program Development

PAUL E. LEAVERTON, Ph.D., Associate Director for ~esearch

ALICE HAYWOOD, Information Officer

DIVISION OF ViTAL STATISTICS

JOHN E. PATTERSON, Director

ALICE M. HETZEL, Deputy Director

ROBERT L. HEUSER, M.A., Chiej Natality Statistics Branch

JOSEPH D. FARRELL, Acting Chief Programming Branch

MABEL G. SMITH, Chief Statistical Resources Branch

Vital and Health Statistics-Series 23-No. 3

DHEW Publication No. {PHS) 79-1979

Library of Congress Catalog Card Number 79-11092
CONTENTS

Inkoduction ...........................................................................................................................................

Summary of Principal Findings ..............................................................................................................

Data and Methods ..................................................................................................................................

Trends in Breast Feeding Among Currently Married Women ..................................................................

Differentials in Breast Feeding ...............................................................................................................

Religion ............................................................................................................................................

Race and Ethnicity ...........................................................................................................................

Farm Background .............................................................................................................................

Geographic Region ............................................................................................................................

Education .........................................................................................................................................

Occupation .......................................................................................................................................

Poverty Level ....................................................................................................................................

Employment .....................................................................................................................................

Marital Status, Parity, and Mother’s Bwth Cohort .............................................................................

Conclusions ...........................................................................................................................................

References ..............................................................................................................................................

Lk.t of Detailed Tables ...........................................................................................................................

Appendixes

I. Technical Notes .......... .......................... .............................................. ......................................

II. Definition of Terms in the Nationsl Survey of Family Growth ..................................................

III. Items on NSFG Questionnaire Related to Breast Feeding .........................................................

LIST OF FIGURES

1. Percent of ever-married women 15-44 years of age who breast fed their first child, by duration of

breast feeding, year of first birth, snd race: United States, 1973 .................................................

2. Percent of ever-married women 15-44 years of age who breast fed their first or second child, by

duration of breast feeding and order of birth: United States, 1973 .. .................................. .........

3. Percent of ever-married women 1544 years of age who breast fed their iirst child, by duration of

breast feeding and employment between first and second births: United States, 1973 .......... ......

LIST OF TEXT TABLES

A. Percent of currently married women who breast fed their first or second child, by bfi cohort of

mother and year of birth of child: United States, 1973 and 1965 ...............................................

B, Percent of ever-married women 1544 years of age who breast fed their first or second chdd, by

duration of breast feeding, birth cohort of mother, and year of birth of child: United States,

1973 ............................................................................................................................................

1

2

3

4

7

9

9

9

9

9

10

10

10

10

12

12

13

27

36

39

2

3

3

4

6

...

Ill
c. Percent of ever-mamied women 1544 years of age with 1 birth or more who breast fed their first

child, by duration of breast feeding, year of first birth, and selected characteristics: United

States, 1973 ........................................ ................................ ...... ...... .......... ................ ................... 8

D. Percent of currently married women 1544 years of age with 1 birth or more who breast fed their

first child, by duration of breast feeding, year of first birth, and selected characteristics: United

States, 1973 ........................................................................ ...................... ................................... 11

SYMBOLS

Data not available--——--—---—--— ------- ---

Category not applicable -------------------- . . .

Quantity zero---------— ------------------------ -

Quantity more than Obut less than 0.05-— 0.0

Figure does not meet standards of

reliability or precision-----–—--–-—–—– *
TRENDS IN BREAST FEEDING

AMONG AMERICAN MOTHERS

Charles Hirschman, Ph.D., Associate Professor, Department of Sociology, Duke University, -.

and Gerry E. Hendershot, Ph.D., Division of Vital Statistics, National Center for Health Stat&tics

INTRODUCTION

In recent decades there was a substantial decline in the proportion of mothers who have

breast fed their children. The decline occurred in

most socioeconomic and cultural groups but was

greater among poor women, black women, and

women with fewer years of education than

among other women. In the early 1970’s the

decline may have leveled off or even reversed,

especially in the West Region, although that

recent change is not large enough to be statistically significant.

The trends and differentials in breast feeding

among American women a-e analyzed in this

report using information collected in the 1973

National Survey of Family Growth and the 1965

National Fertility Study. Trends in the percent

of women who breast fed their first and second

babies and the percent who breast fed them for

3 months or more are examined in reIation to

various socioeconomic and cultural characteristics of the mothers. Trends are examined

across cohorts of women born in the same years,

years of birth of their infants, and the survey

years, 1965 and 1973.

Trends and differentials m breast feeding are

significant in severzd ways. Medical research has

found that mothers’ milk may have health benefits for newborn infants, including short-term

immunity from some diseases and a nutritional

composition that reduces the incidence of both

malnutrition and obesity in breast fed babies.1

Breast feeding also prolongs the period of post

pm-turn amenomhea, thus acting as a natural contraceptive, although for a short interval of uncert tin length .24 Also , it has been suggested

that women who breast feed have a lower risk

of breast cancer mortality,5 but epidemiological

studies have not produced conclusive evidence

of that association.6J Various other physiological and psychological effects on mothers and infants which have been attributed to breast feeding are under scientific investigation.

In spite of the importance of breast feeding,

little information is avaiIable about its prevalence at the present time, trends in the recent

past, or differences among various groups. The

one systematic study with a nationfly representative sample was published in 1974 by

Hirschman and Sweet8 with data from the

1965 National Fertility Study. Hirschman

and Sweet documented a decline in breast feeding up to 1965 and examined its relationship to

education, ethnicit y, farm origin, and a number

of other socioeconomic and cultural characteristics of the mothers. Their analyses considered

breast feeding of first-born infants for any duration bv women who were married and living

with their husbands at the time of interview. In

addition to updating the Hirschman and Sweet

analyses to 1973, this report extends their findings by including second-born infants and by

considering variations in duration of breast

feeding. It also includes all women who have

been married, whether or not they are currently

married.

1
SUMMARY OF PRINCIPAL

FINDINGS

Both the 1973 National Survey of Family

Growth (NSFG) and the 1965 National Fertility

Study (NFS) data show the dramatic decline in

the incidence of breast feeding in recent generations of American women. Trends by birth cohorts of women show that two-thirds of the

women born in the second decade of this century breast fed their first infant, but only onequarter of the women born in the late 1940’s

and early 1950’s did so. A similar trend is

observed in the period rates by year of birth of

infant. Over 70 percent of first-born infants in

the 1930’s were breast fed, while less than 30

percent in the late 1960’s and early 1970’s

were breast fed (see figure 1). The decline

leveled off in the early 1970’s, but it is too early

to say if this foretells a rise in the rate of breast

feeding.

The decline in long-term breast feeding–the

proportion of mothers who breast fed their infants for 3 months or more–has been even ]more

precipitous. According to the 1973 NSFG, less

than 10 percent of the mothers whose first child

IBB Breast fed any dwat,on

““r

m 8reast fed 3 months or more

70 —

60 —

50 —

g

~ 40

?

30 —

20 —

10 —

o

ALL WOMEN’ WHITE BLACK

!4

3

>

.

a

YEAR OF

1Includesv/l,,,,. bl,,k. and ocher,.,.s

Figure 1. Percent of ever-married women 1544 years of age who breast fed their first child, by duration of breast feeding, year of first

birth, and race: United States, 1973
was born from 1966 to 1973 had breast fed

their baby for 3 months or more, a substantial

decline from earlier periods. This indicates that

more than two-thirds of the women who breast

fed their infants in recent years had stopped by

the time the child was 3 months old, presumably

switching to bottle feeding.

Second-born babies are considerably less

likely than first-born babies to be breast fed.

Among breast fed babies, however, second-born

babies are more Iikely than first-born babies to

be breast fed for longer durations (see figure 2).

The level and trend in breast feeding varies

widely across various socioeconomic and cultural categories. Several groups show a very high

incidence of breast feeding, with about 50 percent breast feeding the first baby and with

almost no downward trend in the last 20 years.

Included are women living in the West, women

with 16 years or more of education, and women

who have had jobs as professionals or managers.

Among the groups that have experienced the

40 —

30 -

+

z

g 20 —

:

10 —

o—

39

First ch!!d

27

Second chdd

Figure 2. Percent of ever-married women 1544 years of age

who breast fed their first or second child, by duration of

breast feeding and order of birth: United States, 1973

n

.,.,+ .:,.’.:::;

.:,,,,::

, ::..,.,,, ,,

Not emplowd Employed b. One h,rth .nly

b.lnw?n f,rsl twe. first .nd (n. w+c.nd b,rm)

and WCo”d btrths Wcond D8r1hS

Figure 3. Percent of wer-married women 15-14 years of age

‘who breast fed their first child, by duration of breast feeding

and employment between first and second births: United

States, 1973

most precipitous declines in breast feeding levels

over the past two decades are black women,

women with less than 12 years of education, and

women who have never worked outside the

home. There are small differences in the levels

of breast feeding of first children among women

classified by farm or nonfarm origins, current

poverty status, reIigion, and work experience

between the births of their first and second

children (see figure 3).

DATA AND METHODS

The primary source of data for this study is

Cycle I of the National Survey of Family

3
.

Growth (NSFG-1). In NSFG-1, conducted in

1973 by the National Center for Health Statistics, interviews were held with a nationwide,

area probability sample of 9,797 women aged

15-44 years who had ever been married or who

had children of their own living in the household. The focus of the survey was on fertility,

family planning, and related maternal and child

health topics. The NSFG extends the time series

of earlier cross-sectional fertility surveys done

under other auspices, particularly the 1965 and

1970 NationaI Fertility Studies. Interviewing

was done under contract with the National

Opinion Research Center from July 1973 to

February 1974, centered on September 13,

1973. Further details of the sampling design and

other technical aspects of the NSFG are available in appendix I of this report.

In table A, data from the 1965 National Fertility Study are also used. The 1965 NFS was

similar in content and structure to the 1973

NSFG, but its sample consisted of 5,617 married

women, with spouse present, born after July 1,

1910. When compmisons are made between the

two surveys, only those women who were currently married in the 1973 NSFG are included.

Further details on the sample and content of

the 1965 NFS are available in a report by Ryder

and Westoff.g

Throughout this study, the focus is on

trends and differentials in the proportion of

women who breast fed their babies, not the proportion of babies who were breast fed. With

this focus, the findings presented in this report

show the comparative frequency with which

mothers in different groups have breast fed their

infants.

Because cumulative opportunity for breast

feeding increases with the number of births,

which varies from woman to woman, it is important to compare the behavior of women with

equal numbers of births. The approach in this

report is to analyze breast feeding behavior

separately for women when they had their first

child and when they had their second. In each

case the sample is defined accordingly; that is,

the proportion who breast fed their first baby is

based on the population of women who had one

or more births, and the proportion who breast

fed their second baby is based on the population

Table A. Percent of currently married women who breast fed

their first or second child, by birth cohort of mother and

year of birth of child: United States, 1973 and 19651

Birth cohort of mother

and year of birth of child

All women ......... ...

Birth cohort of mother

1951 -59 .. .. ...... ...... ................

1946-50 ........ ........ ................

194145 ........ ....... ........... .... ..

1936-40 .......... ......................

1931 -35 ................................

1926-304 ............... ...... .........

1921 -25 ..... .......................... .

1916-20 ....... ...... .......... ...... ...

1911 -15 ............. ........ ........ ...

Year of birth of child

1971 -73 .... ....... ....... ....... .......

1966-70 ..................... ...........

1961 -65 ................. .... .... .......

1956-60 ........................... .....

1951 -55 ............................. ...

1946-505 ..............................

194145 ................................

193640 .............................. ..

1931 -35 .............. .............. ....

First child2

1973

38.4

25.6

25.7

37.7

43.2

49.6

47.1

.-.

-..

..-

29.1

28.3

38.0

43.1

48.8

58.9

. . .

. . .

-..

1965

50.5

=

. . .

21.8

34.8

36.6

45.9

47.5

57.8

65.7

68.3

..-

. . .

32.3

36.0

46.6

50.5

64.5

77.4

72.0

Second child3

1973

26.8

16.6

19.8

26.’1

26.8

31.4

32.6

. . .

. . .

---

23.6

22.;7

24.6

28.3

34.4

55.0

..-

..-

. . .

1965

37.6

. . .

13.8

24.1

25.9

30.8

33.4

40.0

49.4

62.8

. . .

..-

22.7

27.5

33.2

41.3

53.7

65.9

75.7

lData from the 1965 National Fertilitv Study include

women born after July 1, 1910; data from t-he 197~ National

Survey of Family Growth, Cycle I, include women 1.5-44 years

ofa e. $

Includes women with 1 or more live births, except that in

1973 babies who did not live with the mother for 2 months or

more are not included.

31nc]udes women with z or more live births, eXCept that in

1973 babies who did not live with the mother for 2 months or

more are not included.

41929.30 for 1973 data.

51950 or before for 1973 data.

of women who had two or more births. In this

approach, comparisons are made among women

whose opportunist y for breast feeding is similar,

insofar as it is determined by number of children, so differences in breast feeding among

socioeconomic groups can be attributed to factors other than number of children.

TRENDS IN BREAST FEEDING

AMONG CURRENTLY

MARRIED WOMEN

By linking the retrospective data from both

the 1965 NFS and the 1973 NSFG into one
time series, a much longer trend analysis is possible than with either survey alone. In order to

compare the 1973 NSFG with the 1965 NFS,

the NSFG sample has been restricted to currently married women, the population represented by the 1965 NFS. Table A shows the proportion of mothers who breast fed their first and

second children, using both the 1965 NFS data

and 1973 NSFG data, according to birth cohort

of women (i.e., the group of women born in the

same period of years) and year of birth of

infant.

In general, the discussion below directs

attention to the larger differences and broader

patterns which may be inferred with confidence

to reflect trends in behavior. There are several

reasons for exercising such caution in inferring

trends from these data. In particular, it should

be noted that the samples of the earliest cohorts

in both surveys underrepresent women in those

cohorts who married relatively late in life. Thus,

comparisons of those cohorts with later cohorts

are affected by differences in average marriage

age as well as differences in breast feeding behavior. AIso, comparisons of the 1965 NFS with

the 1973 NSFG may reflect not only differences

in breast feeding practice, but also some differences in the surveys themselves—sampling variability, minor differences in question wording,

and changes in the population represented due

to aging or marrying. These aspects of the data

are discussed further in appendix I of this

report.

Both the 1965 NFS and “1973 NSFG data

show a dramatic decline in the proportion of

women who have breast fed their children. The

downward trend is evident for both first and

second babies, for trends arranged by birth cohorts of women, and by year of birth of infants.

According to the 1965 NFS, 68.3 percent of

women in the 1911-15 birth cohort breast fed

their first child, but this figure dropped to 34.8

percent of women born in the early 1940’s. The

NSFG data show a continuing decline in breast

feeding among women born in the late 1940’s

and in the 195 0’s. Only about one-quarter of the

women in these recent cohorts had breast fed

their first child.

The cohort trend in breast feeding of second

children is comparable to that of first births,

though at lower levels. For instance, almost twothirds of the women in the 1916-20 birth cohort

breast fed their first child, but only one-half

breast fed their second child. For the more

recent cohort of NFS women, born from 1941

to 1945, over one-third breast fed their first

child, but only one-quarter breast fed their second child. For the youngest cohorts in the

NSFG sample, only about one-fifth of the

mothers breast fed their second child.

According to the 1965 NFS, the period

trend, with data arranged by year of birth of the

infant, shows a similar decline in breast feeding,

from over 70 percent of first-born babies in the

1930’s to slightly above 30 percent in the early

1960’s. The 1973 NSFG data show a similar decline, with a Ieveling off for the most recent

periods. In the early 1960’s, 38.0 percent of

first-born babies were breast fed; this dropped to

28.3 percent in the late 1960’s, but it rose

slightly to 29.1 percent for the 1971-73 period.

This rise is not- statistically significant, - but it

may suggest an approaching end to the longterm secular decline in the proportion of

mothers who breast feed their infants. (See

appendix I for a discussion of standards of statistical reliability used in this report.)

A comparable downward trend with a slight

recent reversal is also evident in the data for second births. The differential between first and

second births noted in the cohort trends, with

mothers being less Iikely to breast feed second

children, also is evident in the data arranged by

periods, or birth dates of infants. For the most

recent periods, about 28-29 percent of mothers

breast fed their first child but only about 23-24

percent breast fed their second child.

Table B shows the proportion of women

who breast fed their infants, divided into two

duration categories–less than 3 months and 3

months or more. Breast feeding of longer duration is more likely to have the effects on mother

and child previously mentioned—immunization

of the baby from some diseases, better nutrition

of the baby, reduced risk of pregnancy for the

mother, and reduced risk of breast cancer for

the mother. Investigators do not know definitely

that breast feeding has all of these effects, and

even less is known about the amount of breast

feeding which may be necessary to produce an

5
Table B. Percent of ever-married women 1544 years of age who breast fed their first or second child, by duration of breast feeding,

birth cohort of mother, and year of birth of child: United States, 1973

Birth cohort of mother and year

of birth of child

All women ..................... ....................................

Birth cohort of mother

1951-59 ................................. ............................................

1946-50 ...... ........ ......... ......... ........ .. ...... .............................

194145 ............................... ........... .......... .................... .....

1936-40 ................. ...................... ........ ........ ...... ........ ...... ..

1931.35 ...................... .............................................. ....... ..

1929.30 ... ...... .................... .............. ....... ............... ........ ....

Year of birth of child

1971-73 ...... ...... .............. ...... ................... ............. .............

1966-70 ...... .......... .............................................................

1961-85 ................. ...... ................. ................ .....................

1956.60 ....................... ........ ........ ........ .............. ........ ....... .

1951-55 ........ ...... .............. ........ ........ ............ .............. .......

1950 or before ........... ....... .................... ............................ .

Duration of breast feeding

~

Percent breast feedi nci

first childl -

3B.6

25.1

25.4

37.8

43.2

50.0

49.6

28.7

27.9

37.5

42.9

49.8

59.9

effect. It is estimated, however, that the contraceptive effect of nursing is not likely to reduce

fertility unless breast feeding continues for at

least 3 months.4 For that reason, 3 months has

been used to divide long- from short-term breast

feeding in this study. Because long-term breast

feeding is more Iikely to affect mother and

child, trends in its incidence are especially significant.

OnIy the 1973 NSFG sample is used in

table B. Unlike table A, in which previously

married women were excluded to make the

NSFG sample comparable to the NFS sample,

table B includes all women who had been married, whether or not they were married at the

time of interview. Because of that difference in

sample coverage, the proportions who breast fed

at all differ somewhat in tables A and B.

The figures in table B show a greater decline

in the proportions reporting long-term breast

feeding than in the overall rate. Among first

births to the oldest cohorts of womei~ in the

1973 NSYG, those born in the late 1920’s and

early 1930’s, there was a nearly equal distribu25.6

21.1

18.7

25.4

27.6

31.3

29.4

21.6

19.7

25.2

29.5

31.7

27.9

13.0

4.0

6.7

12.4

15.6

18.7

20,2

7.1

8.2

12.3

13.4

18.1

32.0

Duration of breast feeding

All Less than 3 months

durations 3 months or more

Percent breast feeding

second child2

27.0

17.8

19.4

26.2

26.7

31.9

34.4

23.5

22.1

24.7

28.1

34.2

56.7

17.0

13.7

14.2

17.1

16.1

19.8

18.8

16.4

15.2

15.4

18.5

19.7

27.1

10.0

4.1

5.2

9.1

10.6

12.1

15.6

7.1

6.9

9.3

10.6

14.5

29.6

lIncludes women with I or more live births whose first baby lived with them for 2 months or more.

21n~ude~ women with 2 or more live births whose second baby lived with them for 2 months or ‘ore.

tion of short-term and long-term breast feeding.

For instance, about 50 pe~cent of alI women In

these cohorts breast fed their first child, and

about 2 out of 5 of them breast fed for 3

months or more. Among the youngest cohorts

of women, those born in the late 1940’s and

1950’s, the overall rate of breast feeding had

been reduced by half to only 25 percent of all

women, and only 1 out of 5 of them ccmtinued

breast feeding for 3 months or more. For second children, the same downward trend was evident, with a greater decrease in long-term

breast feeding than short-term breast feeding.

The pattern by year of birth of the child

parallels that by birth cohort of the mother–a

steep decIine in the fraction of women who

breast fed their infants for 3 months or more.

Furthermore, the decline continues into the

197 O’s, with no sign of an increase in long-term

breast feeding for first children. (The small increase for second children is not statistically significant.) The trend is reaching such a low point,

however, that further decreases must be very

small; less than 10 percent of mothers in recent

6
years have breast fed their first or second infants for 3 months or more.

Two aspects of the trends in breast feeding

deserve emphasis–the large and rapid decline in

breast feeding during the Iast quarter century

and the slowing and possible reversal of that decline in the most recent period. Full analysis of

the causes and consequences of those trends is

beyond the scope of this report, but mention

can be made of some factors which wouId be

included in such an analysis.

The change from breast feeding to bottle

feeding was made possible by improvements in

the technology of bottle feeding, such as premixed, water-soluble, powdered formuIa and the

collapsible, sanitary, disposable plastic bottle,

which made bottle feeding convenient, safe, and

inexpensive. Additional motivation of mothers

to bottIe feed was provided by their increased

opportunities in the workplace and elsewhere

outside the home. Responding to those opportunities required more frequent separation of

mothers from their infants, which could be accommodated better by bottle feeding than

breast feeding. Also, bottle feeding was viewed

as the “modern” feeding method, which encouraged its adoption.lo

As a consequence of the decline in breast

feeding, babies and mothers are now much more

dependent on bottle feeding technology, requiring that high standards of quality in production

and distribution be maintained. Also, to the extent that breast feeding previously provided

some protection against unwanted and untimely

pregnancy by its suppression of ovulation, that

protection must now be foregone or provided by

some other contraceptive means. A further possible consequence of the decline in breast feeding is an increased risk of breast cancer, WhiIe

the role of breast feeding in cancer etiology is

not now considered by leading researchers to be

very important,6~7 it is still under investigation. 11 So long as it is under investigation, some

apprehension will remain about the effect of

the decline in breast feeding on cancer risks.

Finally, the decline in breast feeding may have

consequences for the emotional development of

chiIdren. In the opinion of some developmental

psychologists, breast feeding encourages the

kind of mother-chiId interaction which is necessary for normal psychological development in

the infant. Of course, that interaction can and

usually does occur where bottle feeding is practiced. However, specialists are concerned that

the caring behavior needed to substitute for

breast feeding may not be provided to aIl bottlefed babies.12J~

The sIowing and possible reversal of the decline in breast feeding, if confirmed by subsequent studies, suggests that publicity given the

benefits of breast feeding in recent years, supported by many medical specialists, may be

affecting the choices of mothers and their doctors. Also, the recent growth of organizations to

promote breast feeding in the United States may

be succeeding in redefining breast feeding. No

longer is it denigrated as “old fashioned”; instead, it is accIaimed as “natural,” making its

practice more socially rewarding.1 O

DIFFERENTIALS IN

BREAST FEEDING

As an aspect of child rearing, breast feeding

might be expected to vary among sociaI and cultural groups that have different ideas about how

mothers shouId care for their children, ideas

which are taught to each new generation. Also,

the amount of time and money available to various socioeconomic groups and the advice they

get from doctors, nurses, and other professionals

might influence their breast feeding practices.

In order to highlight some of these variations

among groups, table C shows the proportions of

ever-married mothers who breast fed their first

child and the proportions who breast fed for 3

months or more, according to the year of birth

of the child and seIected cuItural, social, and

economic characteristics.

The characteristics selected are religion, race

and ethnicity, farm background, geographic

region, education, occupation, poverty leveI

income, and work experience. The first four

characteristics are established at birth or in

childhood for many Americans and indicate

membership in social groups which have some

distinctive customs. In comparing breast feeding

practices of women in these groups, there is an

implicit hypothesis that they are influenced by

distinctive breast feeding customs Ieamed in the

group .

7
Table C, Percent of ew?raarried women 1544 years of agewith 1 birth or more who b- fed fheir fimt *iId, by duration of brmst feeding, war of flt’stbirth, and s$fectcddmmcb?rist~

United Sfafes, 1973

Breast fed anv duraoon Breast fed 3 months or more

Year of fv’st birth Y-of first birth

1951-55

18.1

14.8

19.8

+6.s

●if).7

16.7

2s.4

321.4

26.8

13.8

10.s

11.0

282

1S+.0

30.3

22.6

11.8

12.6

12.7

21.2

m.9

11,0

24.1

22.6

34.5

23.C

15.7

13,2

17.E

15.5

W.:

Selected charactermtlc All

women

.41

mm

13.0

950 or 950.X

before

32.0

16.3

35.2

. . .

46.8

26.0

454

37.7

427

23.8

26.5

X.4

40.3

25.6

S8.6

31.2

22.2

54.6

Vafi

41.9

33.4

28.s

36.2

30.0

45.2

38.4

30.3

23.s

36.0

26.0

35,3

171-73 966.70 1881435185660 )71-73 IM55-70 961 ‘Es l?56-m

42.9

1951-55

49.8

Wfore

386 26.7 27,9 375

36.7

36.0

40.9

4s.4

38.9

23.8

39.1

32.8

39.1

30.6

37.4

35.1

49.5

40.1

28.7

32.2

50.4

69,2

33,8

48.s

35.1

395

33.2

34.5

37.3

35.2

40.0

28,4

40.6

37.4

All women,...,...,.. 59.9 7.1 8.2 12.3 13.4

Religm”

Catholic...,...,..., .......... ,,

Protestant............................

Jewish ... ... ........ ... .. ... ..

Other or none...................

Race and ethnicitv

Whine.,...,..,,...,,., ..................

Black, ..................................

Hispanic originl .

Farm background

Farm ...................................

Nonfarm...,..., ......................

Geographic regon

Northeast ......... ... ... ... ... ..

Norfh Central ......................

South .. ... .. ... .... .. .. . .

West .... .............................. .

Educatmn

Elementary school,

8 years or less..................

High school, 9-11 years

High school, 12 years . .... ...

COlles.3,13-15 yearn ...........

College, 16 years or more ....

Occupatmn

Never worked ......................

Professionalsand managers..

Salesand clerical workers ....

Service workers ............ .. ..

Craftworkers, operat!ws,

and farmworkers .. ... ... ..

Poverty level

Below poverty income ........

100.199 percent ..................

20+3.2%3percent ..................

300 percent or more ............

Employment between first

and second births

No secondbirth ...................

Empl eyed between

births.................. .............

Not employed between

bhfhs. ...

. _

38a

44.5

23.1

57,1

43.0

42.1

55.1

44.8

42.2

31.3

42.5

43.8

54.2

52.0

39.8

39.8

47.6

50.2

47,4

51.6

3?92

445

40.9

63.3

46.5

38.(

41,2

38.7

43;

43.(

40.8

54.7

“17.4

42.8

46.8

58.1

57.7

44.4

47.6

41,5

43.3

57.4

54.7

62.3

49.5

44.7

67.0

45.s

43.6

54.5

43.3

56.2

53.5

63.1

54.1

45.5

46.9

43.8

50.0

50,2

52.7

61.0

. . .

82.3

56.2

72.8

73.2

W9

54.5

83.1

58.4

63.8

50.5

63.1

60.4

54.6

69.7

!36.6

62.1

61.4

59.1

88.7

53.4

67.4

88.9

55.7

54.6

67.8

54.7

62.4

10.s

13.8

10.6

17.2

12.5

16.7

30.1

19.0

10.9

10.1

10.0

15.4

16.1

25.0

13.3

8.6

14.4

21.6

16.4

19.2

9.1

14.3

14.2

21.1

13.5

10.3

12.3

7.8

12.2

16.0

5.9

7.0

0.0

15.6

7.6

.1.5

‘3.7

6.3

7.3

6.9

6.3

1:6

‘2.1

5.5

4.s

9.4

19.1

●5,3

17.2

5.2

7.0

“2.E

“58

5.7

7.1

8.5

5.f

“13.:

17.f

7.6

82

‘12.6

9.7

8.5

●3 .9

11.2

8.3

8.1

11.0

5.0

6.1

12.0

12.2

2.7

5.7

9.8

25.4

a9

m.z

5.s

6.3

5.8

10.9

3,6

5.9

12.1

6.5

7.3

9.9

109

11.8

‘23.s

22.6

12.4

9.5

16.3

~2a

12.1

9a

11.2

12.3

16.4

15.1

7.5

9.5

19.9

X.4

17.4

17.6

10.3

11.1

12.2

13.7

14.4

10.3

12.0

10.9

9.0

14.9

13.4

13.4

.4.1

16.4

12.7

18.0

31.7

20.4

10.5

7.6

11.3

17.2

16.6

27.0

15.5

8.6

13.6

19.1

21.9

16.9

9.8

13.1

16.1

27.2

14.9

10.5

loa

12.6

13.8

13.2

34.9

40.3

25.2

44.4

38.9

35.7

43.1

41.5

37,6

32.2

37.0

37,6

49.1

48.1

S4.7

33,3

46.5

58,C

34.C

50.E

,342

42.1

36.1

44.f

39:

34J

38.<

28:

40.!

42.

23.5

29.4

“20.7

46.2

30.2

11.4

19.3

24.3

29.8

23,1

26.5

21,1

53.9

18.1

15.7

24,8

43.5

52.1

13.4

49.2

25.3

32,6

18.6

31,3

31.4

25.6

28.3

27.9

38.2

31.9

27.3

28.5

.18.6

27.0

29.4

13.7

35.2

28,7

28.2

28.9

27.4

22,4

38.2

32.2

17.2

23.3

35.2

57.1

24.4

47,3

24.6

27.1

21 .C

30.1

Z2.f

Z&c

31.;

24.!

28,:

30,4

lThe Hispanic origin classification was msde independently of racial chssitication and includes women of all racial groups.

The second set of characteristics-education, The two types of characteristics ancl the hyoccupation, poverty level income, and work potheses on which they bear, which might be

experience—change during the lifetimes of most called the “cultural” and “socioeconomic” hy -

Americans and affect behavior not so much potheses, were identified by Hirschman and

through custom as through the opportunities Sweet8 in the work previously cited. They conthey open or close. The implicit hypothesis in eluded from their analyses that neither hypothcomparisons involving these characteristics is esis was sufficient in itself to explain observed

that breast feeding Dractice is a matter of choice differences in breast feeding, but both hypothamong alternative; ~etermined by

current socioeconomic situation.

each woman’s eses and possibly others would be required for

a full explanation. In this report, no attempt is

8
made to test these hypotheses formally, but

they have guided the selection of the variabIes

for analysis and presentation.

Religion

It will be noted in table C that among major

religious groups, Protestants are somewhat more

likely to breast feed than Catholic women, and

Jewish women are least likely. For women in

the remaining category of religion “Other or

none,” the proportions who breast fed were

about the same as those for Protestants. The

downward trend over the past decades is evident

for both Protestants and Catholics, although

Protestants show a small upturn (not statistically

significant) in the early 19 70’s, while Catholics

do not. The small samples of women in the Jewish and the “Other or none” categories in some

years preclude interpretation of their trends.

Race and Ethnicity

The overall downward trend in breast feeding is evident for aII three racizd and ethnic categories in table C–black, white, and Hispanic–

but the decline for black women is greatest. For

the earliest periods, the majority of black

women breast fed their first babies, and they

were considerably more likely than white

women to breast feed their babies for 3 months

or more. But by the early 1970’s, only 11.4 percent of black women breast fed their first child,

and only 1.5 percent breast fed for 3 months or

more, compared with 30.2 and 7.6 percent of

white women in the same categories. The decline

of breast feeding among Hispanic women has

been steeper than that among white women but

not as precipitous as among black women. A

modest rise in breast feeding (not statistically

significant) in the 1970’s was present only for

white women and was limited to those breast

feeding for less than 3 months.

Farm Background

The data in table C indicate that before the

1950’s, women who had grown up on farms

were more likely than nonfarm women to breast

feed their children, especially for 3 months or

more. But from the late 1960’s, continuing into

the 19 70’s, the differential has been reversed,

with women of nonfarm background having a

higher proportion breast feeding, although the

differences are not statistically significant.

Women with farm origins continued the downward trend into the 19 70’s, while among women

without a farm background the proportion who

breast fed their first babies did not change significantly.

Geographic Region

There were only minor differentials by geo-

~aphic region for the earliest two periods in the

time series in table C. But as the secular decline

in breast feeding began in the 1950’s and continued into the 1960’s, the West Region was

relatively unaffected. Over 50 percent of women

living in the West Region breast fed their first

baby in the early 1970’s, 13.6 percent for 3

months or more—at Ieast twice the proportions

in other regions of the country. From the late

1960’s to the early 1970’s, an upward trend in

breast feeding was evident in the West Region,

but not in any of the other regions, except for a

small, nonsignificant increase in the proportion

of women breast feeding for 3 months or more

in the North Central Region.

Education

For births occurring in 1950 or earlier, there

were smalI differences in breast feeding between

the educational attainment categories shown in

tabIe C, with a tendency for breast feeding to be

less common among women who completed

high school. In the late 1950’s, there emerged a

U-shaped relationship between breast feeding

and education. Breast feeding was more likely

among women with the least or most years of

education, while women of intermediate education were least likely to breast feed. The pattern

continued to change, and in recent years the

tendency has been for breast feeding to be least

common among those with the least education

and most common among those with the most,

reversing the pat terh reported for babies born 25

years earlier. These changes may also be described in this way: In the past generation,

breast feeding decIined greatly among less educated women, it also declined, but less dramatically, among moderately educated women; and

9
it changed hardly at all among college educated

women.

Occupation

Women are classified by occupation according to the last job they held. The few women in

the sample who had never worked outside the

home are classified as “never worked.” The

other occupational groupings in table C are:

(1) professionals and managers, (2) sales and

clerical workers, (3) service workers, and (4)

craft workers, operatives, and farmworkers. It

should be noted that the occupation in the last

job may not reflect exactly the economic activity of the woman after the birth of her first or

second child, the periods for which her breast

feeding behavior is reported.

There were only small, nonsignificant differentials in breast feeding by occupation for the

earlier periods. By the late 1950’s, a downward

trend was evident for women in all occupations

except those who were “professionals and

managers” and those who “never worked.” In

the “never worked” category, the decline began

later, in the early 1960’s, and accelerated in the

next decade. Since the early 195 O’S there is no

evidence of a consistent downward trend in the

proportion of “professionals and managers” who

breast fed their first babies, either at all or 3

months or more.

Poverty Level

The index of poverty is based on the adequacy of annual family income relative to the

size and composition of the family. In addition

to those below the poverty level, the index is

categorized in table C to show those whose income put them at 100 to 199 percent of the

poverty level, 200 to 299 percent, or 300 percent or more. Because the poverty index measures economic status at the time of interview in

1973 or 1974 and may not reflect accurately the

economic circumstances at the time of first or

second births, its use in analyzing the effects of

income differences on breast feeding is limited.

Poor and near-poor women were more likely

than other women to breast feed babies born before 1960, but breast feeding has declined more

rapidly among poor and near-poor women, so

that in recent years there is less difference between their practice and that of wealthier

women. These trends parallel those observed for

educational groups, and probably have the same

causes, because educational attainment and income are closely related.

Employment

The last variable in table C contrasts women

who worked between their first and second

births and women who did not. A residual category contains women who had not borne a second baby at the time of interview. For the most

recent periods, this residual category contains

most of the respondents because too little time

had passed between the first birth and the interview for many second births to have occurred.

Since working soon after a birth would tend

to reduce opportunities for breast feeding, it

might be expected that women who worked between births would report less breast feeding.

However, from the early 195 O’s on there is no

association between work and breast feeding of

the first child. Women who did not work were

more likely than working women to breast feed

during the earliest period, but the reverse is true

for the most recent period, although the difference is not significant. There are no significant

differences in other periods. However, women

who did not work were generally more likely

than working women to breast feed for more

than 3 months. It does not appear that the increase in labor force participation by mothers is

the sole cause of the downward trend in breast

feeding, because breast feeding has declined

among both groups of women, those who

worked between births and those who did not.

Marital Status, Parity, and Mother’s

Birth Cohort

This discussion of breast feeding differentials

has been limited to statistics on breast feeding of

first-born babies by ever-married women, according to the year of the baby’s birth, as shown

in table C. Table D shows statistics parallel to

those in table C, except that it includes only

women who were married at the time of the interview. There is little difference between com10
Table D, Percent of currently marr$ed women 1544 years of agewtth 1 bwth or more who breast fed xheu frost child, by duratzon of breast feeding, year of f ml bmh, and selected character.

ist!cs: United States, 1973

Breast fed any duratmn Breast led 3 months or more

Year of ftrst bwth Year of fmt b!rth Selected characteristic All

Noreen

38.4

.

34.3

40.2

26.5

42,9

38.8

32,5

41.9

40,7

37.6

31.5

37.2

38,7

49,5

45.6

34.5

33.3

46,5

56,3

35,3

51.1

33.B

41.7

35.5

47.2

38.3

34.4

38.0

28.9

403

41.B

Al[

1950 or women

before

1950 or

before

1971.73

29.1

22,s

30.6

‘20,7

45,5

30,7

%,8

17,7

23.8

30.5

25.3

27,3

21.4

51.9

16.1

lB.5

24.8

41.7

52.9

14.5

48 ,s

24.8

34.2

19.5

37,5

31,2

26,2

28.6

28.0

39,2

35.6

1966-70

26.3

26,7

%:;

27.8

29.4

142

34.7

27.1

2B,6

28.4

26.0

21.7

36.8

33.7

15.2

23.3

35,7

57,6

27.3

4B,2

24,6

28,1

20,2

29,4

23.5

27,0

31.6

260

28.2

30.0

1961-65

3B.o

39.0

36,7

42,9

46,7

3B.8

24,0

38.3

31,5

40.1

28,8

38,6

35.7

51,1

38.6

28.3

32,4

51,8

72,2

38.2

51.9

34.7

40,4

32.5

42.2

35,1

36,2

40,0

26.8

410

38.4

1956-60

43.1

40.0

44.3

32.3

58.6

43.3

39.4

52.3

44.9

42.4

31,1

42.4

43.8

54.9

49.7

38.7

40.2

48.7

52.9

47,1

53,4

39,1

43,9

41.1

53.5

49.1

37.2

42.1

39.3

44,5

42.8

1951.55 1971.73 1966.70 1961-65 1956+C 1951.55

All women..,,. -.,, 48.8

_

39,1

44.3

“17.4

40,7

4B,3

56.3

57.9

54.8

45.9

39.6

42,9

55.9

54.7

59.6

47.6

45.8

57.1

34.0

44.6

50.5

43.4

55.1

52.5

B7 1

56.3

43.6

45.8

43.4

49.B

48.8

56.9

47.6

61.2

. . .

72.8

56.0

74,8

69.3

66.4

53.3

578

57.3

84.0

52,1

57,4

63.6

52.7

67.1

43.6

58.6

61.4

56,0

68.1

53.1

63.5

68.9

61,7

52.2

*.2

K1.6

62.8

12.s

10.8

13,6

11.5

15.8

12,4

15,2

20.0

18,2

10,9

10.2

9.6

15,1

15,8

23,9

13.1

6.7

14,2

21.8

16.7

19,6

8,5

14.0

14.0

243

138

102

121

8.3

11,0

16.0

7,3

_

6.4

7.3

13.2

7.8

●1,6

●4.3

5.9

7.7

7,5

6.1

5.0

13,7

“2.5

6.5

5.1

B.5

18.7

‘6.0

16,5

5.2

B.O

.3.1

.7 1

55

7,4

8,5

5B

“116

19.6

8.7

_

8.4

B,6

‘16,6

9,6

8.9

“42

12.5

8.6

8.7

12,3

5,5

6,4

12,2

14.6

“2.5

5,9

10,4

25,0

10,2

212

57

7.2

6.4

17,1

3.5

6.2

121

7,4

7,9

10,3

12,6

10,8

12,3

250

22.1

12.7

“7.1

15,6

12,4

12,6

8.7

ll,B

13,0

17,1

15.4

7.7

9,8

20.0

27,3

16,9

18,5

10,2

116

12,3

195

146

105

118

!2,3

75

159

13,2

.

13.1

13.4

.4 7

‘14.2

12.6

19,9

30,5

21.1

10,0

7B

11.3

17,1

15,5

23.0

15,5

88

13,3

22,0

20.8

17,2

91

127

172

276

169

100

11 1

15,3

136

127

168

14,2

18,3

“66

.14,9

15,9

26.1

33.5

24.6

12.9

11.2

6,0

27.4

17,6

36,4

21.1

12.0

10,9

“5.8

23,5

19,2

91

229

*,6

375

243

14,9

12.1

149

127

166

318

_

13;

35,2

. .

72.8

26.6

49.7

37,7

42,5

23.9

22,3

24,B

41 B

26,8

39,6

30.8

22.4

582

‘23.6

34.6

400

257

373

290

47,7

418

32,8

238

443

247

347

Race and eth”ictty

White.,...,..,.,,..,,,,..,,,,,,...,...,.

Black .,.,.,...,,, ,, .. .... .. .....

Hupnnic .wpgml ..................

Farm background

Farm ...................................

Nonfarm ........................._.

Geographic reg!on

Northeast ............................

North Central .. . ... .

South .. ... ... .... .. . ...... ...

west ..,,,..,,,.,,..,,,.,.,.,,..,...,...,

Educatmn

Elementary school,

8 years or less ... .. .. . .. . . .. . .

High schoc.lr9.11 years .,.....

H,gh school, 12 yeilrs ..........

College, 13.15 years ............

College, 16 years or more ....

Occupation

Never worked ...,...,,..,......,,..

Professmnak and rna”agxs..

Sales and clerucalworkers,..,

Serwce workers .,.,..,,..,, .......

Craftworkers, cperatw.as,

and farmworkers . ....... ..

Poverty level

Below poverty income.,., .....

100-188 percent ......... ......

200.288 percent .,,..,...,...,...,

300 percent or mcxe............

Employment bewcaen fwst

and second broths

No second bath..., ...............

Employed befwm

b,nhs,.., ...... ... ..................

Not employed between

Maths,..............................

%he Hi$panic origin classification was made independently of racial classiftcatitm and includes women of aU racul groups.

parable statistics in the two tables because most married women, the detailed tables (tabIes 1-12)

ever-married women were currently married, and

breast feeding experiences of currently married

and previously married women are not very

different. The data on currently married women

are presented in table D so that readers may

compare them with the data previously published by Hirschman and Sweet,8 but because

they differ so little from the data for everare presented for ever-married women only. The

detailed tables (tables 5-8) also show differentials among the same socioeconomic and cultural

groups for second-born babies and for different

birth cohorts of mothers. The differentials and

trends found in the detaiIed tables are similar

to those included in the text but differ in some

respects.

11
CONCLUSIONS

Two general conclusions can

the findings in this study. First,

feeding has si~ificant effects

mercially prepared formulas or cow’s milk for

their primary source of nutrition during their

early months of life.

be made from Second, the practice of breast feeding today

even if breast is most common among relatively advantaged

on individual women in society. Among women with college

mothers or children, its overall impact in contemporary American society is relatively minor

because in recent years less than one-third of

mothers have breast fed their first child, and less

than one-tenth have breast fed for 3 months or

more. The fractions are even lower for second

births. This means that the majority of American infants are dependent upon bottle fed, comdegrees and those who - work in high-status

white-collar occupations, about one-half breast

fed their first baby and almost one-fifth continued for 3 months or more. Whether these

higher-than-average levels of breast feeding are

due to socioeconomic and cultural factors or

different medical advice cannot be ascertained

from these data.

REFERENCES

lJelliffe, D. B., and Jelliffe, E. F. P.: Human milk,

nutrition, and the world resource crisis, in Philip H.

Adelson, cd., Food: Politics, Economics, Nutrition and

Research. Washington, D .C. American Association for

the Advancement of Science, 1975, pp. 65-69.

2Jain, A. K,, et al.: Demographic aspects of lactation and postpwtum amenorrhea. Demography 7(2):

255-271, May 1970.

~Saxena, P. C.: Breast-feeding: Its effects upon postpartum amenorrhea. Soc Biol. 24(1) :45-51, Spring 1977.

4 Rolland, R.: Bibliography (with review) on contraceptive effects of breast-feeding. Bibliography R eproductiorz 28(l): l-4,July 1976.

5Kitagawa, E. M., and Hauser, P. M.: Differential

Mortality in the United States: A Study in So cioeconornic Epidemiology. Cambridge, Mass. Harvard University Press, 1973.

6Correa, P.: The epidemiology of cancer of the

breast. Am J Clin Pathol. 64(6):720-727, Dec. 1975.

7MacM&on, B., ad Brown, J.: Etiology of human

breast cancer: A review. Journal of the American Cancer

Institute 50(1) :21-42, Jan. 1973.

8Hirschm~, C., and Sweet, J. A.: Social background

and breast-feeding among American mothers. Soc Biol.

21(1):39-57, Spring 1974.

9Ryder, N., and Westoff, C.: Reproduction in the

United States. Princeton, New Jersey. Princeton University Press, 1971.

10Jelliffe, D. B.: Community and sociopolitical considerations of breast-feeding, in Breast-feeding and the

Mother, Ciba Foundation Symposium 45 (new series).

New York. Elsevier/Excerpts Medics/North-Holkmd,

1976. pp. 159-172.

11Ing, R., and Ho, J. H. C.: Unilateral breast-feeding

and breast cancer. The Lancet 8029:124-127, July 16,

1977.

12 Fraiberg, S.: Every Child’s Birthright: In Defense of

Mothering. New York. Basic Books, Inc., 1977.

13Rossi, A. S.: A biosocial perspective on parenting.

Daedalus 106:1-31, 1977.

14Nation~ center for He~th statistics: Nation~ survey of Family Growth, Cycle I: Sample design, estimation procedures, and variance estimation, by D. K.

French. Vital and Health Statistics. Series 2-No. 76.

DHEW Pub No. (PHS) 78-1350. Public Health Service.

Washington. U.S. Government Printing Office, Jan.

1978.

15Nation~ center for Health Statistics: Replication:

An approach to the analysis of data from complex surveys, by P. J. McCarthy. Vital and Health Statistics. PHS

Pub No. 1000-Series 2-No. 14. Public Health Service.

Washington. U.S. Government Printing Office, Apr.

1966.

12
LIST OF DETAILED TABLES

1. Percent of ever-married women 15-44 years of age with 1 birth or more who breast fed their first child, by birth cohort of

mother and selected characteristics. United States, 1973 ..........................................................................................................

2. Percent of ever-married women 1544 years of age with 1 birth or more who breast fed their first child for 3 months or

more, by birth cohort of mother and selected characteristics: United States, 1973 ........... ........ ...............................................

3. Percent of ever-married women 15-44 years of age with 1 birth or more who breast fed their first child, by year of first birth

and selacted characteristics: United States, 1973 ............................ ...... ..................................................... ......................... ......

4. Percent of ever-married women 1544 years of age with 1 birth or more who breast fed their first child for 3 months or

more, by year of first birth and salected characteristics: United States, 1973 ....................................................... ....................

5. Percent of ever-married women 1544 years of age with 2 births or more who breast fed their second child, by birth cohort

of mother and selected characteristics: United States, 1973 .....................................................................................................

6. Percent of ever-married women 15-44 years of aga with 2 births or more who breast fed their second child for 3 months or

more, by birth cohort of mother and selected characteristics: United States, 1973 ..................................................................

7. Percent of evar-married women 15-44 years of age with 2 births or more who breast fed their second child, by year of second

birth and selected characteristics: United States, 1973 .... .............................................................................................. ...........

8. Percent of aver-marriad women 15-44 years of age with 2 births or more who breast fed their second child for 3 months or

more, by year of second birth and selected characteristics: United States, 1973 . ........... .................................................. .........

9. Number of ever-married women 15-44 years of age with 1 birth or more, by birth cohort of mother and selected characteristics: United States, 1973 ..... ................ ..... ..................................................................... ...... ...................................................

10. Number of ever-married women 15-44 years of age with 1 birth or more, by year of first birth and selected characteristics:

United States, 1973 ............... ............... ...... ............... ...... ........................... ................................... ................. ..........................

11. Number of ever-married women 15-44 years of age with 2 births or more, by birth cohort of mother and selected characteristics: United States, 1973 ........................................................................................................................................................

12. Number of ever-marriad women 1544 years of age with 2 births or more, by year of second birth and selected characteristics: United States, 1973 ..................... ........................................... ........................... ............ ...... ...........................................

14

15

16

17

18

19

20

21

22

23

24

25

13
Table 1. Percent of ever-married women 15-44 years of age with 1 birth or more who breast fed their first child, by birth cohort of

mother and selected characteristics: United States, 1973

Selected characteristic

All women ......................................................

Religion

Race and wthnicity

Farm background

Geographic region

Education

Elementary school, 8 years or less ..................................

High school, 9-11 years ., ................................................

High school, 12 years ........ .............................................

College, 13-15 years .......................................................

College, 16 years or more ...............................................

Occupation

Never worked .............. ...................................................

Professionals and managers ......... ....................................

Sales and clerical workers ...............................................

Service workers ............................................................. .

Craftworkers, operatives, and farmworkers ...... ..............

Povertv level

Below poverty income ....................................................

100-199 percent .............................................................

200-299 percent .............................................................

300 percent or more ............................... ........................

Employment between first and second birth

No next birth .............................................................. ...

Employed between births ...............................................

Not employed between births .................... ....................

Tota I

38.6

34.9

40.3

25.2

44.4

38.9

35,7

43.1

41.5

37.6

32.2

37.0

37.6

49.1

48.1

34.7

33.3

46.5

56.0

34.0

50.6

34.2

42.1

36.1

44.6

39.2

34.5

39.4

28.7

40.9

42.1

1951-59

25.1

23.+

25.5

23.8

27.1

13.8

29.2

26.4

24.8

19.6

24.6

18.2

42.5

22.3

19.7

26.7

47.1

“25.0

12.5

38.5

28.2

32.9

15.7

32.8

25.5

21.8

21.8

25.8

22.2

24.3

Birth cohort of mother

1946-50

25.4

24.2

25.5

34.3

26.6

13.1

33.0

24.3

25.7

19.3

23.3

22.5

38.8

30.9

18.9

21.3

35.6

50.0

28.8

33.6

22.2

29.4

22.3

27.3

, 24.6

25.4

25.3

23.2

28.3

25.6

1941-45

37.8

35.5

38.0

40.3

49.5

38.9

27.6

40.0

35.9

38.4

22.8

35.6

36.4

47.8

47.6

32.7

30.0

46.2

60,9

35.9

54.8

31.4

39.1

35,6

43.2

36.2

34.9

39.3

31.5

39.1

39.3

1936-40

43.2

38.9

44.7

35.4

58.2

42.7

46.3

43.8

43.3

43.2

32.7

43.7

42.3

44.4

53.3

37.0

39.5

45.7

63.4

46.1

57.8

39.2

42.3

40.0

54.8

44.6

38.7

42.2

39.5

46.4

41,9

1931-35

50.0

43.8

53.3

21.9

58.6

48.9

62.1

62.3

55.6

47.2

40.6

45.3

56.2

57.4

58.4

54.7

43.9

58.1

47,1

49.8

51.6

45.3

56.1

51.9

58.5

59.9

45.5

46.4

42.0

51.5

50.7

.—

1!929-30

49.6

————

35.8

56.4

53.8

48.3

59.5

58.8

49.3

49.6

42.4

49.5

54.3

52.8

62.3

51.7

43.6

50.4

55.1

60.4

51.5

41.3

66.1

46.9

59.1

56.6

41.5

48.8

31.2

43.4

54.4

1The Hispanic origin classification was made independently of racial classification and includes women from all racial W2uPs.

14
Table 2. Percent of ever-married women 1544 years of age with 1 birth or more who breast fed their first child for 3 months or more,

by birth cohort of mother and selected characteristic United States, IWJ3

Selected characteristic

All women .......................................... .. .. .... ....

Religion

Catholic ..........................................................................

Protestant ................................... ....................................

Jewish ............................................................ ........ ........

Other or none .................................................................

Race and ethnicity

White .......................... ..... .................................... ...........

Black .......................... ....................................................

Hispanic originl .............................................................

Farm background

Farm ......... .....................................................................

Nonfarm ................... ......................................................

Geographic region

Northeast ............. ...... ............ ..................... ...................

North Central ................... ..............................................

South ............................................ ............... ..................

West ............................. ..................................................

Education

Elementary school, 8 years or less ..................................

High school, 9-11 years .............................................. ....

High school, 12 yaars ................. ....................................

College, 13-15 years .......................................................

College, 16 years or more ...............................................

Occupation

Never worked ......................... ........ .... ...................... ......

Professionals and managers ........................ ........ .............

Sales and clerical workers ...............................................

Service workers ..............................................................

Craftworkers, operatives, and farmworkers ....................

Poverty level

Below poverty income ....................................................

100-199 percent ............................................. ................

200-299 percent ...... .......................................................

300 percent or more .............................................. .........

Employment between first and second birth

No next birth ........................................ .................. .......

Employed between births ........ ........ ...............................

Not employed betwean births ........................................

Tota I

13.0

10.8

13.8

10.6

17.2

12.5

16.7

20.1

19.0

10.9

10.1

10.0

15.4

16.1

25.0

73.3

8.6

14.4

21.6

16.4

19.2

9.1

14.3

14.2

21.1

13.5

10.3

12.3

7.8

12.2

16.0

1951 -5s

4.C

*4.5

3.3

●10.7

4.6

*1.2

●4.4

●5.9

3.6

*2.2

*2.2

*2.3

10.8

*3.8

3.6

4.0

*6.6

‘25.0

●3.7

●7.3

4.6

4.9

*1.8

*4.8

4.0

*2.4

6.7

2.8

●1.7

10.5

Birth cohort of mother

1946-50

6.7

6.5

6.8

8.6

6.7

5.4

15.7

7.1

6.6

6.1

4.6

6.1

11.2

13.6

5.2

4.4

9.8

15.9

11.0

10.3

4.8

7.0

7.4

10.8

5.8

5.4

7.2

4.9

7.7

8.3

194145

12.4

10.2

12.6

*23.3

22.9

12.8

9.7

14.5

14.1

11.9

11.1

10.9

11.7

17.0

19.8

10.5

7.7

16.1

25.7

20.2

20.9

8.8

9.9

13.5

19.7

9.8

10.8

13.3

10.8

10.2

14.6

1936-4C

15.6

12.4

16.7

*16.2

21 .~

14.2

25.6

21.9

19.0

14.1

10.1

14.0

19.1

17.8

28.3

15.0

11.4

13.2

24.9

18.4

20.9

12.2

18.2

14.7

29.3

17.4

11.5

13.4

19.1

14.5

15.6

1931-35

18.7

16.7

19.8

‘5.4

26.0

16.8

34.0

33.3

28.9

13.7

13.5

12.6

28.5

16.8

34.9

25.6

11.5

17.1

18.2

33.2

21.4

10.9

24.8

22.4

35.5

25.7

15.4

13.8

17.6

16.5

19.9

1929-30

20.2

9.0

25.2

*19.4

19.4

25.0

44.2

32.1

15.2

12.6

13.0

29.8

26.8

36.2

22.6 .

14.4

21.5

18.8

*12.9

22.5

14.1

24.9

26.6

25.0

28.4

22.4

16.3

*8.5

18.1

22.5

lThe Hispanic origin classification was made independently of racial classification and includes women frOm all racial grOUpS.

15
Table 3. percent of ever-married women 15-44 years of age with 1 birth or more who breast fed their first child, by year of first birth

and selected characteristics: United States, 1973

Selected characteristic

All women ......................................................

Religion

Catholic ....................................................................... ...

Protestant ............................................... .................... ....

Jewish .......................................................................... ..

Other or none ............................................................. ....

Race and ethnicity

White ................................................................... ........ ...

Black ............................. .................................................

Hispanic originl ......................... ......... ...........................

Farm background

Farm ........................... .................................... ...............

Nonfarm ...... ........................................................... ........

Geographic region

Northeast ................................. ......................................

North Cantral .................................................................

South ............................................................................ .

West ............................................... ................ ................

Education

Elementary school, 8 years or less .............................. ....

High school, 9-11 years ................ ...... ...................... ......

High school, 12 years .....................................................

College, 13-15 years .......................................................

College, 16 years or more ................... ............................

Occupation

Never worked .................................. ....... ......... ...............

Professionals and managers ...... .. ...... ...............................

Sales and clerical workers ...............................................

Service workers ..................................... .. .......................

Craftworkars, operatives, and farmworkers ....................

Poverty level

Below poverty income ....................................................

100-199 percent .............................................................

200-299 percent .............................................................

300 percent or more ................................. ......................

Emtiovment between first and second birth

No next birth ......................................... .. ......................

Employed between births ...............................................

Not employed between births ................ ........................

Total

38.6

34.9

40.3

25.2

44.4

38.9

35.7

43.1

41.5

37.6

32.2

37.0

37.6

49.1

48.1

34.7

33.3

46.5

56.0

34.0

50.6

34.2

42.1

36.1

44.6

39.2

34.5

39.4

28.7

40.9

42.1

1971-74

28.7

23.5

29.4

‘20.7

48.2

30.2

11.4

19.3

24.3

29.8

23.1

26.5

21.1

53.9

18.1

15.7

24.8

43.5

52.1

13.4

49.2

25.3

32.6

18.6

31.3

31.4

25,8

28.3

27.9

38.2

31.9

Year of first birth

1966-70

27.9

27.3

28.5

*18.6

27.0

29.4

13.7

35.2

26.7

28.2

26.9

27.4

22.4

38.2

32.2

17.2

23.3

35.2

57,1

24.4

47.3

24.6

27.7

21.0

30.1

22.5

26.6

31.7

24.5

28.3

30.4

1961-65

37.5

38.7

36.0

40.9

48.4

38.9

23.8

39.1

32.9

39.1

30.6

37.4

35.1

49.5

40.1

28.7

32.2

50.4

69.2

33.8

48,8

35.1

39.5

33,2

34.5

37.3

35.2

40.0

28.4

40.8

37.4

1956-60

42.9

38.8

44.5

23.1

57.1

43.0

42.1

55.1

44.8

42.2

31.3

42.5

43.8

54.2

53.0

39.8

39.9

47,6

50.2

47.4

51.6

39.2

44.5

40.9

53<3

46.5

38.0

41.3

38.7

43.9

43.0

1951-55

49.8

40.9

54.7

+17.4

42,8

48.8

59.1

57.7

44.4

47.6

41.5

43.3

57.4

54.7

62.3

49.5

44.7

57.0

45.8

43.6

54.5

43.3

56.2

53.5

63.1

54.1

45.5

46.9

43.8

50.0

50.2

1950 or

before

59.9

52.7

61.0

82.3

56.2

72.6

73.2

66.9

54.5

63.1

59.4

63.9

50.5

63.1

60.4

54.6

69.7

55.6

62.1

61.4

59.1

66.7

53.4

67.4

66.9

55.7

54.6

67.8

54.7

62.4

1The Hispanic origin classification was made independently of racial classification and includes women frOm all racial grOUPs.

16
Table 4. Percent of ever-married women 1544 years of age with 1 birth or more who breast fed their first child for 3 months or more,

by year of first birth and selected characteristics: United States, 1973

Selected characteristic

All women ......................................................

Religion

@tholic .......... .................................... .............. ..............

Protes~nt ............... .. .............. ...... ..................................

Jewish ............... .................................. ...........................

Other or none .............................................. ...................

Race and ethnicity

White .................................... ...... ............ ........................

Black .......................................... .......................... ..........

Hispanic originl .............................................................

Farm background

Farm .......................... ......................... ...........................

Nonfarm .........................................................................

Geographic region

Northeast ....... ............................. ...................................

North Central ................................... ..................... .........

South .............................................................................

West .......... ... ......................................c............ ....... ........

Education

Elementary school, 8 years or less ..................................

High school,9-11 years ..................................................

High school, 12 years .................................................. ...

College, 13-15 years .......................................................

College, 16 years or more ..... ...... ....................................

Occupation

Never worked .................................................................

Professionals and managers ......................... ....................

sales and clerical workers ............... ................................

Service workers ..............................................................

Craftworkers, operatives, and farmworkers ....................

Poverty level

8elow poverty income ....................................................

100-199 percent .............. ...............................................

200-288 percent .............................. ...............................

300 percent or more .......................................................

Employment between first and second birth

No next birth ....................... ............ ...................... ........

Employed between births ............ ...................................

Not employed between births ........ ........ ........................

Total

13.0

10.8

13.8

10.6

17.2

12.5

16.7

20.1

19.0

10.9

10.1

10.0

15.4

16,1

25.0

13.3

8.6

14.4

21.6

16.4

19.2

9.1

14.3

14.2

21.1

13.5

10.3

12.3

7.8

12.2

16.0

1971-74

7.7

5.9

7.0

15.6

7.6

*1.5

*3.7

6.3

7.3

6.9

6.3

4.7

13.6

*2.1

5.5

4.9

9.4

19.1

*5.3

17.2

5.2

7.0

*2.8

*5.8

5.7

7.1

8.5

5.6

●13.5

17.6

1966-70

8.2

7.6

8.2

*12.6

9.7

8.5

●3.9

11.2

8.3

8.1

11.0

5.0

6.1

12.0

12.2

2.7

5.7

9.8

25.4

8.9

20.2

5.8

6.3

5.9

10.9

3.6

5.9

12.1

6.5

7.8

9.8

Year of first birth

1961-65

12.3

10.9

11.8

*23.8

22.6

12.4

9.5

16.3

12.8

12.1

9.8

11.2

12.3

16.4

15.1

7.5

9.5

19.9

26.4

17.4

17,6

10.3

11.1

12.2

13.7

14.4

10.3

12.0

10.9

9.0

14.9

1956-60

13.4

13.4

13.4

*4.1

18.4

12.7

18.0

31.7

20.4

10.5

7.6

11.3

17.2

16.6

27.0

15.5

8.6

13.6

19.1

21.9

16.9

9.8

13.1

16.1

27.2

14.9

10.5

10.8

12.6

13.8

13.2

1951-55

18.1

14.8

19.8

*6.8

*16.7

16.7

28.4

33.4

26.9

13.8

10.5

11.0

28.2

19.0

38.3

22.6

11.9

12.6

12.7

21,2

20,9

11,0

24.1

22.6

34.5

23.0

15.7

13.2

17.8

15.5

19.2

1950 or

before

32.0

16.3

35.2

48.8

28.0

45.4

37.7

42.7

23.8

26.5

26.4

40.3

25.6

39.6

31.2

22.2

54.6

●18.6

41.9

33.4

26.8

36.2

30.0

45.2

38.4

30.3

23,8

36.0

26.0

35.3

lThe Hispanic origin classification was made independently ofracial classification and includes women from all racial groups.

17
Table5. Percent of ever-married women 15-44 years of agewith 2births ormorewho breast fedtheir second child, by Mrth cohort of

mother and selected characteristics: United States, 1973

Selected characteristic

All women ......................................................

Religion

Catholic ..........................................................................

Protestant .......................................................................

Jewish ............................................................................

Other or none .................................................................

Race and ethnicity

White ..........!... ................................................................

Black ..............................................................................

Hispanic originl ........................................... ......... .........

Farm background

Farm ..............................................................................

Nonfarm .........................................................................

Geographic region

Northeast ............... ........................................ ................

North Central .................................................................

South ..... ........................................................................

West ....................... ...................................................... ..

Education

Elementary school, 8 years or less ............. ........ .............

High school, 9-11 years ........... ........ ........ .................. .....

High school, 12 years ..................................... ........ ........

College, 13-15 years .......................................................

College, 16 years or more ...... .........................................

Occupation

Never worked ..... ........................................ ....................

Professionals and managers ......... .............................. ......

Sales and clerical workers ...............................................

Service workers ..............................................................

Craftworkers, operatives, and farmworkers ................. ...

Poverty level

Below poverty income ............................................. .......

100-199 percent ................... ..................... .....................

200-299 percent .... .........................................................

300 percent or more .......................................................

Employment between second and third birth

No next birth ................... .............. ........ ........................

Employed between tirths ............................. ..................

Not employed between births ........................................

Total

27.0

22.5

29.1

15.5

32.6

26.7

28.9

29.9

31.9

25.2

20.5

24.6

28.2

35.2

32.0

23.5

22.8

34.5

44.2

24.8

37.1

23.6

28.0

26.1

31.6

27.7

22.6

28.3

22.1

30.4

30.8

1951-59

17.8

14.8

16.2

*16.9

19.6

+11.9

*6.5

18.2

17.7

*I 2.4

14,8

16,4

17.1

*6.5

16.1

21.4

61.1

++100.0

*1.6

43.5

17.5

27.0

*11.4

20.8

17.1

10.5

29.4

18.7

*24.1

*8.1

Birth cohort of mother

1946-50

19.4

16.0

21.0

0.0

21.1

20.2

13.2

22.3

18.9

19.5

16.2

15.6

16.6

30.6

18.7

11.2

18.5

33.9

47.7

*9.1

26.1

19.3

23.7

15.8

20.7

15.9

20.3

21.4

20.8

17.3

15.9

1941-45

26.2

21.7

27.2

40.3

39.6

26.9

18.7

24.3

26.2

26.2

21.2

26.8

24.0

33.7

23.9

21.2

21.9

32.6

52,6

26.2

42.4

20.9

30.2

21.3

29.2

21.7

23.7

30.3

25.6

23.9

28.5

1936JI0

26.7

22.3

28.6

*I 5.6

40.1

25.6

26.4

30.5

29.4

25.7

16.5

25.5

28.9

25.4

30.2

22.8

23.8

27.5

47.4

29.9

37.6

24.0

26.3

24,0

33.5

32.3

19.5

26.3

21.6

28.6

29.5

1931-35

31.9

27.6

24.9

++4.4

28.2

30.4

43.5

41.5

40.8

27.5

22.4

26.7

38.2

39.7

43,3

34.1

24.4

42.1

31.9

36.6

37.1

36.8

30.0

36.9

41.1

38.1

27.0

29.5

20.8

41.6

33.6

1929-30

34.4

26,3

38.2

*14.1

*32.3

33.2

45.1

58.6

44.1

30.1

30.8

29.1

39.5

39.4

46.8

36.2

27.6

34.9

44.5

79.3

32.2

30.6

32.6

41.9

49.3

45.6

28.3

30.8

20.8

35.0

42.2

lThe Hispanic origin classification was made independently ofracial classification andincksdes women from dIraChlWOtSfJS.

18
Table6. Percent of ever-married women 15-44 years of age with 2 births or more who breast fed their second child for 3 months or

more, by birth cohort of mother and selected characteristics: United States, 1973

Selected characteristic

All women ...................................... ................

Religion

Catholic ........................................... ...............................

Protestant .......................................................................

Jewish ............. ...............................................................

Other or none ........ ..................................................... ....

Race and ethnicity

White ........................................................................... ...

Black ........................... ................................................ ...

Hispanic originl .............................................................

Farm background

Farm .................. .................................... ........................

Nonfarm ...................................................... ...................

Geographic region

Northeast ........................................ ..... ...................... ....

North Central .................... ....................................... ......

South .............................................................................

West ...... ................................. ... ............ ....... ..................

Education

Elementary school, 8 years or less ..................................

High school,9-11 years .................................... ......... .....

High school, 12 years .................................. ...................

College, 13-15 years .......................................................

College, 16 years or more ....... ................ ........................

Occupation

Never worked ..... ......... ...................................................

Professionals and managers ................... ..........................

Sales and clerical workers ...............................................

Service workers ..................... ........ .................................

Craftworkers, operatives, and farmworkers ....................

Poverty level

Below poverty income ............................................. .......

100-199 percent ......... ........... .........................................

200-299 percent ...................... ........................... ............

300 percent or more .... ........... ........ ................................

Employment between second and third birth

No nextibirth ............................................ .....................

Employed between births ............... ....... .........................

Not employed between births ..... ............... ..... ........ .......

Total

10.0

8.3

10.8

7.6

10.3

9.3

15.3

15.3

13.5

8.6

7.7

9.7

11.4

10.5

15.1

9.5

7.2

11.1

18.6

12.6

14.8

7.1

9.8

11.6

14.3

10.7

7.0

10.2

7.2

10.6

12.7

1951-59

4.1

*2.6

*3.9

*8.7

*3.3

*7.5

0.0

*4.3

●4.O

*4.9

*4.8

*3.5

*3.5

*1.O

*1.8

*7.7

‘20.6

*100.O

1.1

0.0

●4.9

●8.2

‘0.6

*1.O

*3.6

*6.9

*8.5

*3.9

“7.4

Birth cohort of mother

1946-50

5.2

3.7

6.3

●0.3

5.4

*4.2

‘7.3

6.0

4.9

6.1

●3.1

4.6

7.7

*5.2

●2.7

4.4

8.1

30.4

*8.2

●9.1

5.2

●2.7

5.7

6.4

4.2

4.8

6.2

5.3

“4.2

5.4

1941-45

9.1

7.2

9.0

*27.4

19.3

9.5

6.8

13.1

11.5

8.4

7.6

9.8

8.5

10.8

10.5

6.3

6.9

12.1

21.1

18.5

15.5

6.9

8.3

7.4

12.4

6.8

7.2

11.2

8.9

7.9

10.2

193640

10.6

9.9

11.0

●7.6

+10.1

9.3

21.2

17.4

11.1

10.3

5.3

11.6

14.1

9.3

16.1

10.9

7.6

10.2

19.8

‘11.7

15.8

7.7

12.0

10.9

18.3

14.6

5.4

9.3

6.2

10.5

13.8

1931-35

12.1

10.7

13.2

*12.5

10.4

26.8

20.0

18.6

8.9

9.3

10.9

15.5

11.6

20.1

15.6

7.6

11.3

14.6

13.4

14.6

7.4

13.2

17.0

19.6

16.1

8.9

10.2

7.3

14.7

13.6

1929-30

15.6

10.2

18.5

*2.8

15.0

22.0

49.2

20.5

13.5

12.5

13.5

18.6

18.5

25.4

20.1

12.0

13.7

13.5

*29.O

17.0

9.3

15.6

26.8

30.3

20.7

12.7

13.3

12.9

15.4

17.3

lThe Hispanic origin classification was made independently of racial classification and includes women from all racial groups.

19
Table7. Percent of ever-married women 1544 years of age with 2births ormorewho breast fedtheir second child, byyear ofsecond

birth and selected characteristics: United States, 1973

i

Selected characteristic

All women ......................................................

Religion

Catholic ................. ....................... ..... ................ .............

Protestant ................................... ........ .. ..........................

Jewish ............................................................................

Other or none .. ..................................... ..........................

Race and ethnicitv

White ......................................................................... .....

Black ........................................... ...................................

Hispanic originl .............................................................

Farm background

Farm ..............................................................................

Nonfarm .........................................................................

Geographic region

Northeast .......................................................................

North Central .................................................................

South .............................................................................

Education

Elementary school, 8 years or less ..................................

High school, 9-11 years ..................................................

High school, 12 years ................. ............................ ........

College, 13-15 years .......................................................

College, 16 years or more .................................. .............

Occupation

Never worked .................................................... .............

Professionals and managers .............................. ....... ........

Sales and clerical workers ............ ...................................

Service workers ..............................................................

Craftworkers, operatives, and farmworkers ....................

Poverty level

Below poverty income ............................................ ........

100-199 percent ................................. ............................

200-299 percent ................................. ............................

300 percent or more .......................................................

Employment between second and third birth

No next birth .................................................................

Employed between births ...............................................

Not employed between births ............. .............. ..... ........

Total

27.0

22.5

29.1

15.5

32.6

26.7

28.9

28.9

31.9

25.2

20.5

24.6

28.2

35.2

32.0

23.5

22.8

34.5

44.2

24.8

37.1

23.6

28.0

26.1

31.6

27.7

22.6

28.2

22.1

30.4

30.8

1971-74

23.5

21.1

23.9

*24.7

31.5

24.9

12.3

21,8

24.0

23.3

23.1

25.1

17.5

30,9

14.5

9.8

20.3

38.8

49.8

*6.8

43.8

21.9

23.8

16.1

24.0

15.4

25.5

28.1

24.2

18.2

Year of second birth

1966-70

22.1

16.6

23.0

“27.0

44.2

22.6

12.6

12.7

19.2

23.0

16.8

19.4

18.9

35.6

12.7

14.1

18.9

28.9

53.3

19.7

39.1

18.8

26.3

12.6

16.6

18.0

21.6

26.9

21.3

24.1

22.8

1961-65

24.7

22.1

26.4

29.9

21.3

24.9

23.3

33.3

25.8

24.4

16.8

22.6

26.8

33.4

27.4

19.6

22.9

31.1

40.0

22.5

30.5

22.9

26.8

23.0

30.8

26.0

19.3

25.6

18.3

26.9

28.5

1956-60

29.1

25.3

31.9

24.1

28.3

35.3

43.0

36.3

25.9

18.2

26.1

33.6

38,3

40.1

30.4

24.0

33.5

33.3

32.1

38.4

24,3

26,6

32.8

39.5

36.5

21.6

26.6

22.4

28.8

32.2

1951-55

34.2

29.0

26.1

*14.1

41.4

32.3

49.1

38.4

42.6

30.0

33.2

29.9

38.3

34.4

36.8

32.6

28.4

51.6

45.3

31.2

37.2

30.8

34.6

37.8

46.5

40.6

24.7

32.4

23.6

40.4

34.4

1950 or

before

.—

56.7

42.1

59.8

*53.6

54.3

62.6

67.0

71.0

42,0

56.4

49.5

66.3

47.0

66.9

53.6

49,7

*38.9

0.0

92.2

*10.5

58.0

42.6

69.4

56.0

58.6

52.9

57.6

61.6

58.6

55.0

-—

lThe Hispanic origin classification was made independently of racial classification andincludes women from all raCial&TCUPLL

20
Table8. Percent of ever-married women 15-44 years of age with 2 births or more who braast fed their second child for3 months or

morerby year of second birth and selected characteristics: United States, 1973

Selected characteristic

All women ......................................................

Religion

Catholic .............................. ................................... .........

Protestant ............ ...... ........ .................... .........................

Jewish ............................................................................

Other or none ...................... .............. .............. .............. .

Race and ethnicity

White ..............................................................................

Black ......... ........................................ ...... ......... ...... ........

Hispanic origin 1 .......... ............... ....... ............... ..............

Farm background

Farm ...... .............................. ..........................................

Nonfarm . ................................................... ............... ......

Geographic region

Northeast .......... .................................. ..... ......................

North Central ......... ......... ....................................... ...... ..

South ...................... ...... .................................................

West ...................... .................. .... ........ ....... ....... .............

Education

Elementary school, 8 years or less .... ................. ............ .

High school, 9-11 years ...... ........................ ..... ........ ..... ..

High school, 12years ..... ....................................... .........

College, 13-15 years .... ........................ ..... ..... .... .............

College, 16 years or more ..... ............................ ..... ... ......

Occupation

Nevar worked ......................... .... ... ........ ... .... ..................

Professionals and managers ............ ... .... ....... ...................

Sales and clerical workers ..... ............................. ........ .. ...

Service workers ....... ..................... ................. ........ .... .....

Craftworkers, operatives, and farmworkers .......... ........ ..

Povertv level

Below poverty income ......... .................... ......... ..... .........

100-199 percent .... ...... .. ................ .... ........ ......e...... ........

200-299 percent ............ .................................... .............

300 percent or more ................................................ .......

Employ mentbetween second and third birth

No next birth ......... ................................... ...... .......... .... .

Employed between bifihs ............................ ..... ...... ..... ...

Not employed between births ............ ......... ..... ..............

Total

10.0

8.3

10.8

7.6

10.3

9.3

15.3

15.3

13.5

8.6

7.7

9.7

11.4

10.5

15.1

9.5

7.2

11.1

18.6

12.6

14.8

7.1

9.8

11.6

14.3

10.7

7.0

10.2

7.2

10.6

12.7

1971-74

7.1

6.5

7.7

*6.1

7.5

‘4.4

‘7.5

7.9

7.0

7.7

8.7

6.1

6.1

*2.9

*0.1

7.3

9.5

19.4

*6.8

13.2

6.4

6.5

*4.9

*4.4

3.4

7.3

11.6

6.7

0,0

17.7

Year of second birth

1966-70

6.9

3.8

7.4

*19.6

16.1

7.0

●4.8

*3.3

7.6

6.6

6.2

6.0

5.5

10.7

“4.2

3.6

4.7

12.3

18.9

14.8

13.9

6.0

4.7

4.2

5.9

4.3

6.5

9.1

6.3

7.8

7.6

1961-65

9.3

10.2

8.9

*12.2

*5.9

9.1

10.8

22.2

11.6

8.4

7.5

9.3

10.1

9.8

13.7

6.2

7.1

11.5

24.6

10.1

13.3

8.2

8.0

9.4

14.5

9.9

4.4

10.4

7.0

7.5

12.0

1956-60

10,6

9.1

11.5

*15.4

9.8

18.0

15.6

12.4

9.9

7.4

12.0

12.3

9.6

14.5

15.1

8.4

6.3

13.8

●5.4

‘f7.4

5,0

12.7

15.2

15.2

16.5

6.7

8.5

7,2

11.3

11.9

1951-55

14.5

11.5

16.2

*1.4

13.0

26.1

27.0

22.4

10.7

8.4

10.0

21.4

15.5

18.8

16.6

9.6

20.8

‘13.7

‘1 5.6

15.7

11.9

14.3

18.0

25.4

20.6

9.8

11.4

12.2

14.2

15.3

1950 or

before

29.6

24.2

30.8

*23.3

21.5

49.4

51.1

36.3

22.8

34.2

29.0

37.6

12.8

46.4

24.4

*14.7

●2B.9

0.0

70.7

●6.5

*9.8

25.9

42.8

48,9

20.2

29.5

26.0

45.0

28.0

28.4

lThe Hispanic origin classification was made independently of racial classification and includes women frOm all racial gr0uP5.

21
Table9. Number of ever-married women 15-44 years of age with 1 birth or more, by birth cohort of mother and selected

characteristics: United States, 1973

Selected characteristic

All women ...................................................

Religion

Race and ethnicity

Farm background

Geographic region

Education

Elementary school, 8 years or less ...............................

High school, 9-11 years .............................................. ..

High school, 12 years ...................................................

College, 13-15 years .....................................................

College, 16 years or more ............................................

Occupation

Never worked ..............................................................

Professionals and managers .............. ............................

Sales and clerical workers ............................................

Service workers ................................ ...........................

Craftworkers, operatives, and farmworkers ..................

Povertv level

Below poverty income .................................................

?O0.199 percent .......... ....... .........................................

200.299 percent ................... .......................................

300 percent or more ....................................................

Employment between first and second birth

No next birth .................................................. .............

Employed between hrths ............................................

Not employed between births ......................................

Birth cohort of mother

Total II1951-59

I

1946-50 1941-45 1936-40 1931-35 1929-30

Number in thousands

24,454

6,978

16,084

398

993

21,525

2,680

1,795

6,396

18,058

5,083

6,461

7,967

4,942

2,355

5,243

11,655

3,099

2,101

1,166

3,670

9,835

4,965

4,816

2,647

5,578

6,308

9,920

5,710

7,006

11,736

2,259

528

1,592

5

135

1,895

350

203

391

1,868

304

578

906

471

242

772

1,103

141

2

25B

73

820

593

515

388

848

586

438

1,573

288

397

4,943

1,382

3,211

55

294

4,354

546

399

1,031

3,912

910

1,267

1,784

982

356

972

2,598

693

324

234

587

2,078

1,050

994

548

1,159

1,471

1,765

1,970

1,365

1,609

5,391

1,657

3,428

73

232

4,790

554

371

1,278

4,713

1,225

1,435

1,594

1,136

371

1,005

2,551

847

616

259

910

2,245

993

985

510

1,159

1,500

2,223

1,000

1,761

2,630

4,956

1,444

3,245

117

150

4,398

484

408

1,464

3,492

1,052

1,312

1,537

1,055

515

1,066

2,339

554

482

174

799

2,049

1,046

888

543

1,112

1,269

2,032

488

1,705

2,763

5,084

1,474

3,346

112

152

4,465

553

? 48

1,688

3,396

1,131

1,361

1,642

949

635

1,067

2,253

627

501

202

953

1,918

922

1,088

543

959

1,161

2,420

532

1,412

3,140

1,821

494

1,261

36

30

1,623

193

67

544

1,277

460

508

503

349

237

360

811

236

176

39

349

725

361

347

116

343

322

1,041

148

476

1,197

1The ~i~Panic origin ~la~5ification ~aS made independently of racial classification and includes Wornm from ~1 racial WWPS.

22

.
Table 10. Number of ever-married women 15-44 years of age with 1 birth or more, by vear of first birth and selected characteristics:

Selected characteristic

Ail women ............. ..... .. ........................... ....

Religion

Catholic ..... ......... ........ .................... ............ .............. ...

Protestant .... ...... .............. .......... ...... .... ...................... ..

Jewish ... ......... ..... .. ...... ........ ...... ..... ... ............. ............ ..

Other or none .............. .............. ...... .......... ........... ...... .

Race and ethnicitv

White ........ .................... ............... ..... .............. ... ... .......

Black ...... .......... ..................... ..... ...... .......... ..... ..... ...... .

Hispanic origin 1......................... .............. .... ...... ..... .....

Farm background

Farm .... .......... ..... .......................... .......... ...... ..... ..... .....

Nonfarm ...................... ..... ... ............ ...... .......... ............

Geographic region

Northeast. ..... .......... ............... ..... .... ............... ..... ..... ....

North Central ................ ........... ..... .......... ....................

South ....... ...... .. ........ .... ......... ............ ...... .......... ..... ..... .

West .......... .. ................... ...... .................... ...... .......... ....

Education

Elementary school, 8 years or less ..... ..... ...... .... ...... .....

High school, 9-11 years ............ ..... ..... .......... ..... ..... ..... .

High school, 12 years .. ...... ...... .............. ...... ..... ..... ..... ..

College, 13.15years ................. ..... .... ..... ..... ..... .... ...... ..

College, 16 years or more ........ ..... ......... .............. ........

Occupation

Never worked ........ ...... ............ .. ............ .......... ............

Professionals and managers ......... ..... ..... ............ ..... ......

Sales and clerical workers .............................. ..............

Service workers ........................ ........ ............ ...... ...... ....

Craftworkers, operatives, and farmworkers ...... .......... ..

Poverty level

Below poverty income ....................... ..... ........ ...... ...... .

100-199 percent ................. ........ ....... ..... ...... ......... ... ...

200-289 percent .. .. ..................... ..... ...................... ......

300 percent or more ...... ...................... ........... ..... ........

Employment between first and second birth

No next birth .............. ..... ............... ........ .. ...... .... ........ .

Employed between births ... .... ......... .. ........... ...... .........

Not employed between births .... .... ............ ..................

Un;ted States, 1973

Year of first birth

Total 1971-74 1966-70 1961-65 1956-60 1951-55 1950 or

before

Number in thousands

24,454

6.97E

16,084

398

993

21,525

2,680

1,795

6,396

18,058

5,083

6,461

7,967

4,942

2,355

5,243

11,655

3,089

2,101

1,166

3,670

9,835

4,965

4,816

2,647

5,578

6,308

9,920

5,711

7,007

11,736

2,973

855

1,888

43

187

2,668

263

235

564

2,410

540

824

1,084

525

207

482

1,517

407

361

181

482

1,301

539

470

312

749

814

1,088

2,566

125

283

5,875

1,769

3,751

68

287

5,184

623

467

1,177

4,688

1,307

1,444

1,901

1,224

410

1,073

2,959

839

595

281

857

2,434

1,235

1,059

602

1,354

1,726

2,193

1,850

1,762

2,263

5,103

1,575

3,178

98

252

4,532

513

375

1,264

3,839

1,108

1,401

1,608

986

354

1,101

2,534

682

431

241

777

2,153

922

1,010

534

1,143

1,350

2,075

631

1,857

2,614

4,988

1,393

3,324

100

171

4,438

499

328

1,444

3,544

1,071

1,392

1,479

1,046

471

1,061

2,426

573

457

210

808

1,995

967

1,007

499

1,205

1,261

2,023

374

1,575

3,039

4,031

1,117

2,760

89

65

3,560

443

316

1,300

2,731

850

1,050

1,279

851

540

933

1,815

513

229

164

561

1,596

877

812

465

755

694

1,917

208

1,160

2,663

1,484

269

1,184

30

1,143

341

75

648

835

208

349

617

310

374

593

403

86

28

79

164

357

425

458

235

373

262

614

82

528

873

lThe Hispanic origin classification was made independently ofracial clawification andincludes women from allracial groups.

23
Table Il. Number of ever-married women 15-44 years of age with 2 births or more, by birth cohort of mother and selected

characteristics: United States, 1973

Selected characteristic

All women ........ ......................... ............... ...

Religion

Catholic ............ ...... .................. .............................. .....

Protestant ......... ............ .......................... ...... ...... .. .......

Jewish ............................................. ...... .............. .. .......

Other or none ........................ ........ ...... ........ ........ ...... ..

Race and ethnicity

White ...... .............. ....... ....... ....... ....... ........ ...... ....... ......

Black ......... ........................................ ....... ....... ............

Hispanic origin 1.......................................... ...... ........ ...

Farm background

Farm .. ........................ ........ ...... ........ .............. ...... ........

Nonfarm .... ....... ........ ....... ....... ........ ...................... .......

Geographic region

Northeast ................. .. ...... ........ ........ ...... .................... ..

North Central ......................... ...... .. ................. ....... .....

South ....................... ...... ................................. ....... ......

West .......... ...... ........................ ...... ..... ...... ...... ..............

Education

Elementary school, 8 years or less ....... ...... ..... ..... .. .....

High school, 9-11 years ............. ............ ................ .......

High school, 12 years ................ ............ ...... .......... .. .....

College, 13-15 years ...... ...... ... .............. ...... ..... ...... ..... ..

College, 16 years or more ...... ....... ...............................

Occupation

Never worked ........... ....... ....................... .......... ....... ....

Professionals and managers, ...... ...... ...... ...... ...... ....... ....

Sales and clerical workers .. .......... ...... ....... ....... ...... .... ..

Service workers ......... ...... ...... ............ ...... ...... ...............

Craftworkers, operatives, and farmworkers.. .......... ......

Poverty Ievel

Below poverty income ......... ........................ ...... ... .......

100.199 percent .................. ....... .......... ..... ...... .... ...... ..

200.299 percent .. .. .............. ..... ........... ...................... ..

300 percent or more ......... .... ...... ..... .......... ............... ...

Employment between first and second birth

No next birth ......... .... .... ................... ...................... .....

Employed between births ................ ........ ... .................

Not employed between birth s.......... ....... ........ ........ .....

Birth cohort of mother

Total II1951-59 1946-50 1941-45 1936-40 1931-35 1929-30

Number in thousands

18,891

5,583

12,304

328

676

16,700

2,014

1,427

5,162

13,729

4,029

5,090

5,845

3,927

1,991

4,347

8,741

2,350

1,462

901

2,740

7,457

3,923

3,870

2,177

4,544

4,964

7,206

7,936

3,621

7,333

155

476

65

546

140

69

134

563

104

173

263

156

99

359

216

21

95

31

184

210

176

162

345

128

61

580

40

76

3,033

930

1,919

21

163

2,640

369

307

654

2,378

568

771

1,021

673

271

773

1,537

369

83

195

220

1,174

726

718

426

869

1,012

726

2,014

388

630

4,409

1,348

2,821

63

177

3,941

446

300

1,037

3,372

975

1,213

1,297

925

332

904

2,104

667

402

234

649

1,842

859

B26

463

1,038

1,287

1,622

2,124

852

1,433

4,471

1,319

2,930

101

121

3,974

437

367

1,321

3,150

942

1,218

1,369

941

473

980

2,133

491

395

155

674

1,845

952

845

531

1,046

1,186

1,708

1,429

1,050

1,992

4,583

1,360

2,985

107

130

4,063

458

328

1,500

3,083

1,021

1,231

1,436

895

606

991

2,003

571

413

.

187

843

1,717

844

992

495

912

1,062

2,115

1,264

1,004

2,315

1,699

470

1,172

36

20

1,534

165

57

516

1,183

420

483

459

336

210

340

748

231

169

35

322

695

332

315

100

335

289

975

525

286

887

lThe Hispanic origin classification was made independently of racial classification and includes women frOm all racial grOUPS.

24
Table 12. Number of ever-married women 1544 years of aga with 2 births or more, by year of second birth and selected

characteristics: United States, 1973

Selected characteristic

All women ....... .......... .... ....... ....... ....... ....... ..

Reliaion

Cathodic ..... .................................. ........ ................ ...... ..

Protestant ............... ............... ...... .............. ..................

Jewish ............................... .....i . ....... ....... ...... ...... ..........

Other or none .................................. ............... ....... ......

Race and ethnicity

White ......... ....... ..... ................................ ......... ...... .......

Bl=k .......... ........ ...... ........ .............. ....... ....... ....... .......

Hispanic origin 1.......... ... .................. ........ ...... ..............

Farm background

Farm ........................................................... ....... ..........

Nonfarm ........ ....... ...... ....... .............. ................ .... ....... .

Geographic ragion

Northeast .... .. ...... ........ ...... ................................ ........ ...

North Central ....... ...... ........ ...... ...... ........ ....... ....... .......

South ... ................ ...... ........ ........ ...... ................ ............

west ....................... .................. .............. ........ ....... .......

Education

Elementary school, 8 years or less .... ................ ......... ..

High school, 9-11 yaars ........ ...... ...... ........ ...... ....... .......

High school, 12 years .. ....... ..................... ....... ........ .... ..

College, 13-15 years .................. ...... ........ ........ .............

College, 16 years or more ................. .. ....... ..................

Occupation

Never worked ....... ...... ...... ...... ........... .... ....... ...... ...... ...

Professionals and managers ................ ...... ....... ...... ..... ..

Sales and clerical workers .... ........ ....... ....... ...... ...... ......

Service w6rkers ............... ....... ..... ................ ....... ...... ....

Craftworkers, operatives, and farmworkers, ....... ... ... ....

Poverty level

Below poverty income ..... ............ ................................

100-199 percent ......... ....... ............. ....... ............ ........ ..

200-289 percent ... ............. ...................... ............. .......

300 percant or more ................................. ....... ...... ......

Employment between first and second birth

No next birth ......... .... ........ ...... ....... .. ...... ....... ...... .. ......

Employed between births ........ .................. ...... .... ........

Not amployad between births ............. ....... ....... ...........

Year of second birth

Total 1971-74 1966-70 1961-65 1966-60 1951-56 1950 or

bafore

Number in thousands

18.681

-

5,583

12,304

328

676

16,700

2,014

1,427

5,162

13,729

4,028

5,080

5,845

3,927

1,881

4,347

8,741

2,350

1,462

901

2,740

7,457

3,923

3,870

2,177

4,544

4,964

7,206

7,936

3,621

7,333

2,573

844

1,547

33

149

2,316

224

230

495

2,078

600

646

800

527

166

519

1,268

347

274

150

371

1,120

463

469

231

767

819

767

2,398

43

132

4,352

1,292

2,800

63

196

3,641

449

335

1,051

3,301

955

1,162

1,322

912

361

873

2,090

615

413

208

604

1,775

933

B31

549

942

1,307

1,554

2,554

583

1,204

4,478

1,362

2,838

104

174

3,970

450

352

1,168

3,310

978

1,259

1,332

910

422

1,034

2,186

525

311

219

641

1,771

873

974

517

1,126

1,123

1,712

1,472

1,0!31

1,915

4,549

1,358

2,985

92

113

4,068

463

286

1,391

3,158

989

1,252

1,451

856

472

1,007

2,108

602

369

179

736

1,785

943

9fx3

525

1,027

1,148

1,649

1,071

1,117

2,360

2,460

643

1,741

36

40

2,164

280

194

816

1,644

445

657

744

615

398

737

965

259

100

110

369

882

543

545

267

535

473

1,195

401

623

1,436

479

84

393

2

340

139

29

242

237

63

115

195

106

172

177

122

3

5

34

18

114

17

146

99

147

95

139

40

153

266

LThe Hispanic origin classification was made independently of racial cbrsaification and includes women from df r~cid iVoUPs.

25
APPENDIXES

CONTENTS

I. Technical Notes ..............................................................................................................................

Background .........................................................................................................................

Statistical Design .................................................................................................................

Measurement Process ...........................................................................................................

Data Reduction ...................................................................................................................

Reliability of Estimates .......................................................................................................

Nonsampling Error ..............................................................................................................

The 1965 National Fertility Study ............................................................................................

Background ................~........................................................................................................

Standard Emors ...................................................................................................................

Differences Between NSFG and NFS Estimates ........................................................................

II. Definition of Terms in the National Survey of Family Growth .......................................................

III. Items on NSFG Questionnaire Related to Breast Feeding ..............................................................

LIST OF APPENDIX FIGURES

I. Relative standard errors for aggregates of women, by race .............................................................

II. Relative standard errors for percent of total and white women (base of percent shown in curve in

thousands) ...................................................................................................................................

LIST OF APPENDIX TABLES

I. Approximate standard errors for estimated percents expressed in percentage points for white

and total women: 1973 National Survey of Family Growth ........................................................

II. Approximate standard errors for estimated percents expressed in percentage points for black

women: 1973 National Survey of Family Growth .......................................................................

III. Standard errors for estimated percents for currently married white women and currently married women of all races based on data from the 1965 National Fertility Study ............................

27

27

27

28

28

28

29

34

34

35

35

36

39

30

31

32

32

34

26
APPENDIX I

TECHNICAL NOTES

Background

This report is one of a series of statistical reports based on information collected from a

nationwide sample of women by the National

Survey of Family Growth conducted by the National Center for Health Statistics.

The National Survey of Family Growth

(NSFG) utilizes a questionnaire to obtain demographic information and information on fertility, family planning, and health factors related

to childbearing. AS data relating to various subjects within these broad topics are tabulated and

analyzed, separate reports are issued. The present report is based on data collected in the first

cycle of the survey, which was centered on September 1973.

The population covered by the sample for

the NSFG is women 15-44 years of age living in

households in the conterminous United States

at the time of interview who were ever married

or had offspring living with them. The sample

did not include women living in institutions or

group quarters. Personal interviews were conducted by the staff of the National Opinion

Research Center (NORC), Chicago, beginning in

July 1973 and ending in February 1974.

Statistical Design

The sampling plan for the survey was a multistage probability design. Black households and

households of all other races were selected at

different probabilities so that the sample was

composed of about 40 percent black women and

60 percent women of all other races. The sample was designed so that tabulations could be

provided for each of the four geographic regions

of the United States.

The first stage of the sample design consisted

of drawing a sample of primary sampling units

(PSU’S). A PSU consisted of a county, a small

group of contiguous counties, or a standard

metropolitan statistical area as defined by the

U.S. Bureau of the Census in March 1971. The

second and third stages of sampling were used to

select several segments (clusters of about 100

dwelling units) within each PSU. A systematic

sample of dwelling units was then selected from

each segment. Each sample dwelIing unit was

visited by an interviewer who listed all household members. If a woman 15-44 years of age,

ever married or with offspring in the household,

was listed as being in the household, an extended interview was conducted. If more than

one woman in the household met the eligibility

criteria, one of the women was randomly

6e]ected for an extended interview.

Since the design of the NSFG was a complex

multistage probability sample, the derivation of

estimates involved three basic operations:

Inflation by the reciprocal of the probability

of selection. —The probabflit y of selection is

the product of the probabilities of selection

from each step of selection in the design

(PSU, segment, listing unit, household, and

sample persons within household).

Norwesponse adjustment. —The estimates

were inflated by a multiplication of two factors. The first has the number of sample

households in a given PSU and stratum as its

numerator and the number of households

screened in the PSU and stratum as its denominator. The second factor has as its

numerator the

holds with an

number of screened houseeligible woman of a specific

27
age and race class and PSU group, and as its

denominator, the number of women actually interviewed in the same age and race

class and PSU. Screener response for the

total survey was 89.8 percent and interview

response was 90.2 percent for the total sample, yielding an overall response of approximately 81.0 percent.

Poststratification by marital status-agerace. —The estimates are ratio adjusted

within each of 12 age-race cells to an independent estimate of the population for evermarried women. These independent estimates were derived from the U.S. Bureau of

the Census Current Population Surveys of

1971-73. The numbers of ,single women with

offspring living with them were inflated by

steps 1 and 2.

All figures are individually rounded; aggregate figures are rounded to the nearest thousand.

The sums of aggregates and percentages may not

add up to the total due to the rounding.

The effect of the ratio-e,stimating process is

to make the sample more closely representative

of the population of women 15-44 years of age,

liting in households in the conterminous United

States, and ever-married or with offspring living

with them. The final postratification reduces

the sample variance of the estimates for most

statistics.

Descriptive material on the sampling design’

and estimation Procedures may be found in

another report.14”

Measurement Process

Field operations

ducted by NORC as

for the survev were con- /

agent for NCHS. Their responsibilities included ‘pretesting the interview

schedule, selecting the sample, interviewing respondents, and carrying out quality control

checks. The questionnaire was pretested in

November 1972, and subsequent smaller field

trials were held in March 1973. Interviewers

were trained for a week prior to fieldwork and

had their first few schedules reviewed thoroughly. During the first part of the fieldwork,

each interview schedule was reviewed for the

completeness of certain key items and more intensive review and followup were performed if

errors were discovered. Review and followup

were reduced to a sample of each interviewer’s

work in the later part of the fieldwork. A 10-

percent sample of all households with telephones was recontacted to verify the interview

and the accuracy of a few items. All of these

operations were monitored by NCHS.

The parts of the interview schedule applicable to this report are reproduced in appendix 111.

The complete schedules are available upon

request. Two different forms were used, one for

interviewing currently married women and the

other for interviewing widowed, dlivorced,

separated, or single women with their own children living with them. The two forms differ

mainly in wording when reference is made to the

husband; there are a few questions in each

schedule that do not appear in the other.

Data Reduction

Coding and keying were done by NORC and

the U.S. Bureau of the Census. Each coder’s

work was systematically sampled for verification. Keying at the U.S. Bureau of the Census

was performed on key-to-disk equipment programed to reject invalid entries. Each keyer’s

work was systematically sampled for verification. The data were edited by the U.S. Bureau of

the Census and NCHS to minimize internal inconsistencies. After editing, value entries were

imputed to cases with missing data on an itemby-item basis. No item with more than 15

percent missing data was included in the imputation. The imputed value entry for a case was

selected from a randomly chosen case with

similar characteristics such as race, age, and

marital status, using a procedure known as “hot

deck” imputation.

Reliability of Estimates

Since the statistics presented in th’is report

are based on a sample, they may differ somewhat from the figures that would have been obtained if a complete census had been taken using

the same questionnaires, instructions, interviewing personnel, and field procedures. This

chance difference between sample results and a

complete count is referred to as sampling error

28
and is measured by a statistic called the standard

error of estimate. The relative standard error of

an estimate is obtained by dividing the standard

error of the estimate by the estimate itself and

is expressed as a percentage of the estimate.

Included in this appendix are charts and tables

from which the relative standard errors can be

determined for estimates shown in this report.

In order to derive relative errors which would be

applicable to a wide variety of health statistics

and which could be prepared at a moderate cost,

a number of approximations were required. As

a result, the charts provide an estimate of the

approximate relative standard error rather than

the precise error for any specific statistic. The

standard errors were computed using a procedure known as balanced half-sample replication.1 5

The chances are about 68 out of 100 that an

estimate from the sample would differ from a

complete census by less than the standard error.

The chances are about 95 out of 100 that the

difference between the sample estimate and a

complete count would be less than twice the

standard error. In this report, numbers and percentages which have a standard error that is

more than 25 percent of the estimate itself are

considered “unreliable.” They are marked with

an asterisk to caution the user but may be combined to make other types of comparisons of

greater precision.

In this report, sample statistics are compared

among subgroups or across years, using the

normal deviate test at the 0.05 level of confidence. A statistically significant difference

among comparable proportions of other statistics from two or more subgroups is one sufficiently greater than zero that a difference of

that size or larger would be expected in less than

5 percent of repeated samples of the same size

and type if there were no true difference in the

populations sampled. If the observed difference

or a larger one could be expected in more than 5

percent of repeated samples, one cannot be sufficiently confident to conclude that there is a

true difference in the populations. When an observed difference is sufficiently greater than zero

to be statistically significant, the true difference

in the population is estimated to lie between the

observed difference plus or minus 2 standard

errors of that difference in 95 out of 100

samples.

When two or more sample statistics are compared and they have only smaIl, statistically nonsignificant differences among them, the y may be

referred to as the “same” or “’similar.” However,

where a substantial difference observed is found

not to be statistically significant, one should not

conclude that no difference exists, but simply

that such a difference carmot be established with

95-percent confidence from this sample. Observed differences that are described in terms

such as “greater,” “less,” “ku-ger,” “smaller,”

etc., have been tested and found statistically

significant. Lack of comment in the text about

any two statistics does not mean the difference

was tested and found not to be significant.

The standard error of a difference between

two comparative statistics, say the proportion

with characteristic M among black women compared with white women, is approximately the

square root of the sum of the squares of the

standard errors of the statistics considered

separately, or calculated by the formula,

d=P1 -P2

is

‘d =

where PI is the proportion for one group, and

P2 the proportion for the comparative group,

and VPI and VPZ are the relative standard errors

of PI and P2, respectively. This formula will

represent the actual standard error quite

accurately for the difference between separate

and uncorrelated characteristics, although it is

only a rough approximation in most other cases.

The relative standard error of various proportions can be estimated from figures I and II

and tables I and H for statistics based on the

National Survey of Family Growth.

Nonsampling Error

In addition to sampling error, the survey results are subject to severaI sources of potential

nonsampling error , including interview nonresponse, nonresponse to individual questions

within the interview, inconsistency of responses

29
, , , ,

1111111 I I I I [Ilvl Ii

111111111 I f

VI

1111111111 I 1111 IIAI

cd

m

e

Lrl

w

h

I l/1 I I I I I I i 1 I I I 1 1

I

30
Figure II. Relative standard errors for percent of total and whita women [baseof Percentshown in curve in thousands)

100

90

80

70

60

50

40

30

20

10

9

8

7

6

5

4

3

2

1

.9

.8

.7

.6

.5

.4

.3

.2

.1

A234 56

1 t , r ,

t

I 1 I I 1 I t

f

3ase of percent (thousands) I

, ,

1 , , r , 1 [

I 1 1

1 1 1 t 1 1 1 t

Ill

I I I I J I II

789

A2345

10

m IIJ.

t

1 I I 1 1 I I

M!

6789

A

2 3

“i

456789

100 1,000

ESTIMATED PERCENT

E.vample Oj-usc OJ- chart. .4n estimate of 10 percent (from the scale at the bottom of the chart) of

a population sub,~roup of 1 million ~~wmen (fifth curve from the tc~p) has a relative standard erro; of

20.0 percent, or a standard error of 2.0 percent (20.0 percent of 10 percent).

to individual questions, respondent error or mis- ures can be made of some types of nonsampling

reporting, and errors of recording, coding, or error, the survey must rely upon severaI qua,lity

keying by survey personnel. It is impossible to controI procedures and other methods incorpomeasure the extent of non sampling errors accu- rated into the survey design to minimize nonrately. Although some useful approximate meas- sampIing error.

31
Table 1. Approximate standard errors for estimated percents expressed in percentage points for white and total women: 1973 National

Survey of Family Growth

Base of percentage

loo.ooo ..............................................................................................................

3.000.000 ....... ...... ........................ ....... ...... ...... ............ ....... ............ ................. ...

5.000.000 ..................... ........ ....... .......... ......................................................... ....

7.000.000 ............. ...... ......................... ...... ...... ........... ...... ............. .................. ...

lo.ooo.ooo .........................................................................................................

I

Estimated percent

2 or

98

3.0

1.3

0.9

0.5

0.4

0.3

0.3E

5 or lOor 20 or

95 90 80

4.6 6.4 8.5

2.1 2.8 3.8

1.5 2.0 2.7

0.8 1.2 1.5

0.6 0.9 1.2

0.5 0.8 1.0

0.5 0.6 0.8

-t-+

30 or 40 or so

70 60

9.7 1CI.4 10.6

4.3 4..6 4.7

3.1 3.3 3.3

1.8 1.9 1.9

1.4 1.5 1.5

-_d-Elx

Table Il. Approximate standard errors for estimated percents expressed in percentage points for black women: 1973 National Survey

of Family Growth

Base of percentage

2 or

98

5.mo .... ...... ............ ...... ...... ...... ............ ...... ...................................... ...... ...... ......

lo.ooo ........................................................................................c.......................

50,000 .... ............... ............... ..............................................................................

loo.ooo ..............................................................................................................

3oorooo ....... ....... ........... .........m............. ....... ...... ...... ................... ........................

5oo.ooo ...... ...........c..............c...... ......... ...... ...... ...... ...... ...... ...... ...... ........ ...... ......

7oo.ooo ........ .......+.................. ............... ............. ............. ....... ............................

l.ooo.ooo ............ .. .................................................... ...... ................ ...... .............

7.9

5.6

2.5

1.8

1.0

0.8

0.7

0.6

Interview Nonresponse. –Interview nonresponse, or the failure to obtain whole interviews,

arises from several sources—incomplete listing of

households for the sampling frame, inability to

screen all sample households for eligible respondents, and inability to complete a full interview. Completeness of listing cannot be tested

directly as it requires an independent, accurate

accounting of the households that should have

been listed. In the NSFG, listing accuracy was

tested at the time of screening by use of the

“half open interval” check for missed households; i.e., at designated sample households, the

interviewer was required to check for dwelIing

units between the sample household just

screened and the next listed dwelling unit. This

procedure resulted in the addition of 781 missed

units or an additional 2.4 percent to the original

sample of dwelling units to be screened.

Of the original sample of 32,818 dwelling

units to be screened, 3,820 were found to be

vacant, not dwelling units, or group quarters. Of

the remaining dwelling units, 9.7 percent were

32

Estimated percent

m

12.3

8.7

3.9

2.7

1.6

1.2

1.0

0.9

17.0

12.0

5.4

3.8

2,2

1.7

1.4

1.2

22.6

16.0

7.1

5.1

2.9

2.3

1.9

1.6

25.9

18.3

8.2

5.8

3.3

2.6

2.2

1.8

27.7

19.6

8.8

6.2

3.6

2.8

2.3

2.0

28.3

20.0

8.9

6.3

3.6

2.8

2.4

2.0

not successfully screened. This included 2.3 percent refusals to have the household members

listed; 1.6 percent with language problems, illness, or otherwise unavailable in the field period;

4.6 percent where no one could be found at

home; and 1.1 percent for other reasons such as

refused access to the unit.

Of the 26,177 households for which screening was completed, 10,879 were found to contain an eli~ble respondent. However, interviews

were not completed in 9.8 percent of these cases

because of refusals by the eligible respondents

(5.0 percent); language, illness, and related

problems (2.0 percent); and no contact after

repeated calls (2.7 percent).

The nonresponse adjustment for interview

nonresponse described above imputes to nonresponding dwelling units and women the characteristics of similar respondent dwelling units

and women.

Item nonresponse.–Nonresponse to individual questions (item nonresponse) was less than

2 percent for about half (51 percent) of the
items. Item nonresponse occurred when the person refused to answer the question, when the

person did not know the answer to the question,

when the question was erroneously not asked or

the answer not recorded by the interviewer, and

where the answer was uncodeable. For 37 percent of the items, nonresponse was between 2.0

and 10.0 percent. For the remaining 12 percent

of the items, nonresponse was greater than 10

percent of persons eligible to answer the items.

Half of these high nonresponse items were concentrated in two areas-detailed income questions and questions about the reasons for switching from one contraceptive method to another.

The remaining high nonresponse items were generally those asked of small numbers of persons.

The amount of missing data or imputed

values for various items will usually be shown

with the definition in appendix II, especially

where it is substantial. Some illustrative items

with their associated nonresponse rates are: the’

number of children ever born (parity) (no

missing data), intentions about having another

child (O.7 percent), whether contraception was

stopped in order to become pregnant (1.9 percent), highest grade of school attended (O.1 percent), and total family income (6.8 percent).

For most items an adjustment for missing

data values was made by one of four imputation

procedures. In order of frequency employed

they were: (1) “hot deck” imputation, (2) imputation from a sorted file, (3) editing from

other data within the same case, and (4) aUocation based on technical judgments.

“Hot deck” imputation refers to a procedure

in which the file is first randomized. Next a

matrix is created for values of items (e.g., race,

age, and marital status) judged to be correlated

with the item to be imputed (e.g., number of

times married). A reasonable “cold deck” value

(e.g., 2 = married twice) is assigned to each cell

of the matrix in case the first file record with

the given characteristics has missing data. The

randomized file is processed and each record is

identified as belonging to one cell of the matrix

(e.g., white, age 25-29, currently married). The

item to be imputed is checked: if it is blank–

not applicable (e g., not married before), it is

ignored; if it has a missing data code, the code

in the matrix is placed in the record. If it has an

acceptable code, that code replaces the code

already in the matrix, and it remains in the

matrix until another record with the same characteristics and a known code is encountered.

This insures that the probability of a code being

assigned to a record with missing data is the

same as the probability of that code occurring

among records with the same characteristics

but with known data.

For imputation from a sorted file, the records are first sorted by selected characteristics

(e.g., marital status, race, and age) so that the

first group of records wouId be currently married black women aged 15-19, the second group

would be currently married black women aged

20-24, etc. An initial value is assigned for the

item to be imputed—(e.g., 4 [tubzd ligation] for

type of sterility )-and for any item dependent

upon the item to be imputed—(e g., 9 [not

ascertained] as to whether the operation was for

contraceptive wasons). The ordered file is processed and each record is checked. If the item to

be imputed is blank-not applicable, it is ignored; if it has a known code, it and its dependent items would replace the existing set of

values; if it has a missing data code, it and its

dependent items would be changed to the preset

values above. This procedure insures that the imputed code is reasonable for the ordering characteristics and that the probability of assignment

is the same as in the population in general. There

will be some bias, however, as the boundaries

between groups are crossed.

Where sampling error affects the precision

of survey estimates, nonsampIing error introduces bias. Imputation procedures reduce this

bias to the extent that the assumptions about

the relations between respondent and nonrespondent characteristics are true. But the

amount of remaining bias, if any, cannot be

measured. Therefore, stringent quality control

procedures were introduced at every stage of

the survey, including the check on completeness

of the household listing mentioned earlier, the

extensive training and practice of interviewers,

field observation of interviewers, field editing of

questionnaires, short verification interviews with

a subsample of respondents and missed households, verification of coding and editing, an

independent recode of a sample of questionnaires by NCHS, keypunch verification, and an

extensive computer “cleaning” to check for

33
impermissible codes, missing data, and response

inconsistencies. One source of bias that can be

evaluated through special studies but cannot be

controlled is respondent error, whether deliberate or unwitting. In this as in other surveys,

the data are subject to problems of accurate

recall and of the stability of respondents’ views

from one time to the next.

Age-at-mam”age bias.–It should be noted

that among birth cohorts only those members

who have been married or have children living

with them are included in these samples. Since

most American women are married before age

25, the women interviewed at ages over 25 are

quite representative samples of all women in

their cohorts. But women interviewed under age

25, and especially under age 20, are not representative of all women in their cohorts because

the survey does not include the numerous

women in their cohorts who had not yet married

at the time of interview. In other words, the

samples of women in recent cohorts, the young

women, include only early-marrying women,

while the samples of women in earlier cohorts,

the older women, include both early- and latemarrying women. In comparing recent and

earlier cohorts, therefore, groups are being compared which have different age-at-marriage

compositions. To the extent that age at marriage

is associated with breast feeding practice, comparisons between cohorts are affected by differences in age-at-marriage composition in addition

to any effects of historical trends in breast feeding practice. This kind of problem is inherent

in a survey such as the National Survey of

Family Growth, which reconstructs past events

from reports of a szuiiple of women interviewed

at one point in time. It cannot be solved completely and should be kept in mind by the reader

as a caution to the interpretation of comparisons

between cohorts.

THE 1965 NATIONAL FERTILITY

STUDY

In this report, NSFG data are sometimes

compared to data from the 1965 National Fertility Study (NFS).

Background

Like the 1973 NSFG, the 1965 NI?S collected information on fertility and family pkmning. The target population consisted of currently married women born since July 1,, 1910,

who were living with their husbands and residing in the conterminous United States. The

survey was conducted by the Office of Population Research at Princeton University and sponsored by the National Institute of Child Health

and Human Development. National Analysts,

Inc., of Philadelphia drew the area probability

sample, conducted the interviews, edited ~d

coded the questionnaires, and prepared the basic

data file.

The interview completion rate in the study,

defined as the number of successfully completed

interviews divided by the estimated number of

women eligible to be interviewed, was 88 percent. Of the 12 percent not interviewecl, some

two-thirds, or 8 percent, were classified as

“refusals;” the remainder were cases of the

Table I I 1. Standard errors for estimated percents for currently married white women and currently married women of all races based on

data from the 1965 National Fertility Study

Number of women in thousands

500 ..... ................................. ....... ....... ....... ............................ .................... ......................

l.ooo ......... ............. ................ ............................. ...... ........c..... ....... ....... ....... ..................

2,000 ............... ................................. ............ ........ ............................................ ........ ......

5rooo ... ........ ...... ........ ..i .... ................. ................l ................. ........................................ ...

10,000 .... ..... ........ ..... ................... ...... ...... .................. ...... ....... ...... ......................... .........

2orooo.....................................................................................#....................................p.

Estimated percent

6 or 10or 20 or 30 or

95 90 80 70

f

4:;r 50

2.4 3.4 5.0 5.4 5.5

1.7 2.8 3.2 U 4.0 4.0

1.2 1.7 2.4 2.7 2.8 2.9

0.9 1.2 1.6 1.8 2.0 2.0

0.7 0.9 1.3 1.5 1.5 1.6

0.6 0.8 1.1 1.2 1.3 1.3

34
respondent not at home despite calls and other

miscellaneous reasons. Interviews were completed with 5,617 women. Furthe; discussion of

the design and conduct of the survey is found in

the study report by Ryder andWestoff.15

Standard Errors

Standard errors for the 1965 National Fertility Study are measures of sampling variability, the variation that occurs by chance because

a sample of units is surveyed rather than the entire population. The chances are about 68 out of

100 that an estimate from the sample would

differ from the population value by less than 1

standard error, about 95 out of 100 that the difference would be less than twice the standard

error, and about 99 out of 100 that the difference would be less than 21A times the standard

error.

The contractor for the 1965 survey produced tables of approximate standard errors for

percentage estimates from which table Ill in this

appendix was derived.

DIFFERENCES BETWEEN NSFG

AND N FS ESTIMATES

It will be noted that the NFS and NSFG

data for the same birth cohorts and years of

birth yield somewhat different estimates of the

proportions breast feeding. Several factors may

contribute to these differences. First, the data

are from probability samples, and two probability samples drawn independently from the same

population wiI.I produce different estimates of

the same statistics, within theoretically known

limits. Most of the differences between estimates

of the same statistics from these two surveys are

so small that it is likely that they resulted from

chance sampling factors.

Second, there were small differences in the

questions on breast feeding asked in the two

surveys. The 1965 NFS simply asked women if

they had breast fed the baby, while the 1973

NSFG asked if they had breast fed the baby “at

all.” It is possible that women with identical

breast feeding experience would answer those

two questions differently. Also, in 1965 the

question about breast feeding was asked about

all babies, but in 1973 it was asked only about

babies who lived with the mother for 2 months;

thus, breast feeding of babies who died or were

separated from their mothers within 2 months

was included in the 1965 survey but not in the

1973 survey.

Finally, the 8-year interval between the surveys affects estimates for the same birth cohorts

and years of birth. The 1965 sample of a birth

cohort represents women who were mothers

at that time. By 1973, more women from the

same cohort had become mothers, making them

eligible for the sample. Thus, the 1973 sample

from a birth cohort represents more mothers

than the 1965 sample from the same cohort; the

larger 1973 sample might also be somewhat different, on the average, from the 1965 sample.

Comparisons between the two surveys for the

same years of babies’ births are affected in a related way. Some of the women who reported in

1965 on breast feeding of babies born in a particular period would have become too old (45

years of age) to be included in the 1973 survey.

Thus, the 1973 sample of women reporting on

babies born in that period would be somewhat

smaller and possibly somewhat different, on the

average, than the 1965 sample reporting on the

same birth period.

000

35
APPENDIX II

DEFINITION OF TERMS IN THE NATIONAL SURVEY OF FAMILY GROWTH

Breast feeding. –For each of her children

who lived with her for at least 2 months after

birth, mothers were asked, “When (CHILD) was

an infant, did you breast feed him/her at all?”

If so, women were then asked, “How many

weeks old was he/she when you quit breast feeding him/her altogether?” Women who answered

the first question affirmatively were considered

to have breast fed the child regardless of the

length of time reported in the following question. Reporting on breast feeding was very complete; for instance, breast feeding status of the

first child was ascertained for more than 99 percent of respondents.

Birth cohort. –A birth cohort is a group of

women born in a specified calendar period. Because the information for classifying women in

birth cohorts comes from a sample of women

who were married, previously married, or single

with children of their own living in the household, it may be a biased sample of all women

born in a specific period. Women who were born

in a specific period but who were never married

and without children at the time of the interview would not be represented in the birth cohorts constructed from these data. This bias is

negligible for early birth cohorts (older women),

because very few of them had not married by

the time of interview; but the bias is significant

for recent birth cohorts, because many of them

have not yet married or borne children and are

not represented in the sample. The effect of

their omission is a relative overrepresentation of

early-marrying women in the recent birth

cohorts constructed from the sample data.

Marital status. –Marital status was a criterion

of sample selection. The NSFG sampled women

who were currently married at the time of interview, had ever been married, or had never been

married but had offspring (i.e., children born to

them) in the household. Current marital status

was recorded in seven categories in response to

the question, “Is (PERSON) now married,

widowed, divorced or annulled, separated, or has

he/she never been married?” The seven categories in which answers were recorded were married, informal union, widowed, divorced or

annulled, separated, single with own clhildren,

and never married. Women in the last category

were not eligible for the survey.

Married women include those who are

legally or formally married whose husbands are

living in the household or are temporarily absent

on business, illness, vacation, etc., and those

who are informally married or “living together”

with a male partner whose usual residence is the

same household. Women currently in informal

unions were reported separately but are too few

to be separately classified for analytical purposes. Information on informal unions was oh-,

tained only if volunteered by the respondent in

the course of listing household members and

their relationship to the head of the household.

Divorced women include those legally separated from their former spouses by a legal decree

of divorce or anmdlment and free to remarry.

While those legally separated but without freedom to remarry belong in the later category of

separated, there was no direct question in the

interview to establish the issue of freedom to

remarry with certainty. The term divorce is presumed to refer most generally to “absolute”

decrees.

Widowed women are those previously married women whose most recent spouses are

deceased.

Separated women are those legally or informally separated from their former spouses.

36
IncIuded here would be cases of desertion, informal separation by mutual agreement, and

legal separations in which the partners are not

free to remarry.

Single with own children is a category of

women who have begun their childbearing and

have never been married. However, some of

these women were probably missed in the survey

because this’ category was not identified by a

direct question. These are single women who

have one or more children born to them and

Iiving with them in the household. Single women

who gave a child up for adoption or who board

the child elsewhere and those who have not had

a live birth are not included in the survey.

l?eli~”on. –Women were classified by reIigion

in response to the question, “Are you Protestant, Roman Catholic, Jewish, or something

else ?“ In addition to the three major religious

groupings, two other categories—other and

none—were used. Since the category of Protestant includes numerous individual denominations, these respondents were further asked to

identify the denomination to which they

beIonged. Those who answered “other” to the

original question and then named a Protestant

denomination were then included with their

own groups. Although specific denominational

names were obtained and recorded, the numbers

of cases for most denominations were too few to

produce reliable estimates, so they have been

combined in larger categories. Data on religious

denominations were reported for all but 26

respondent cases, more than 99 percent, and

these few cases were imputed.

Race and ethnicity.–Women were classified

as white, bIack, or “other races” according to

the interviewer’s observations at the time of

interview. Agreement between this classification

and the respondent’s own reports of ethnic

origin, also obtained in the interview, was very

high; for instance, of those classified as “black”

by interviewer observation, 100 percent reported their ethnic origin as at least partly

“black, African, or Negro”; and of those who

reported their ethnic origin as “black, African,

or Negro,” 96 percent were classified as “black”

by interviewer observation. Race was imputed

for 10 cases.

Information about ethnic origins was obtained for the woman by asking, ‘What is your

origin or descent?” Persons were classified as

being of Hispanic origin if any of the following

responses were given: Mexicano, Chicano, Mexican American, Puerto Rican, Cuban, Hispano, or

any other Spanish origin or descent. Persons

who did not give any of those responses were

classified as being not of Hispanic origin. Persons

may have more than one origin or descent, and

multiple responses to the questions were recorded. However, any of the responses listed

above resulted in classification of the person as

being of Hispanic origin regardless of any other

responses which may have accompanied it. It

should be noted that in this report the classifications of race and ethnicit y are independent;

each ethnic category may include persons of all

races, and each racial category may include persons of aU ethnic groups. Ethnicity was reported

for more than 99 percent of respondents.

Farm background. –Women were asked,

“When you were growing up, that is, between

the ages of 6 and 16, did you live on a farm

most of the time (half of the time or more)?”

Women who answered affirmatively were classified as having a farm background, and others

were classified as having a non farm background.

Responses were obtained from more than 99

percent of sample women. Note that the term

“farm” was not defined for respondents, so

there may be considerable variation in the childhood experience of those who reported a farm

background.

Education. –Education is classified according

to the highest grade or year of regukir school

or college that was completed. Determination

of the highest year of regular school or college

completed by the respondent is based on responses to a series of questions concerning (a)

the last grade or year of school attended, (b)

whether or not that grade was completed, (c)

whether any other schooling of a vocational or

generally nonacademic type was obtained, and

(d) whether or not such other schooling was included in the years of regular school or coIIege

reported in (a). Information on education was

reported almost completely. Only about 1 percent of the data was imputed.

Occupation. –Occupation was determined by

asking women: “What (is/was) your (main) occupation? That is, what (is/was) your job called?

What (are/were) your most important activities

37
or duties? What kind of place (do/did) you work

for? What do they make or do?” The answers to

those questions were recorded verbatim and

used by coders to find the most appropriate

standard job title in the 1970 U.S. Census occupation classification. If the responses indicated

more than one occupation, the primary occupation was coded. If none was primary, the first

mentioned occupation was coded. Although the

classification used was very detailed, occupations have been grouped into major categories

for this report according to the practice of the

U.S. Bureau of the Census. For a more detailed

discussion, see the Department of Commerce

publication, “1970 Census of Population, Detailed Characteristics, U.S. Summary,” PC (1)

Dl, pp. A17-A18.

Poverty level. –The- Federal Government

periodically estimates the amount of income

needed by male- and female-headed families of

different sizes to purchase essential goods and

services, the “poverty threshold.” (See U.S.

Bureau of the Census, Current Population

Reports, Series P-60, No. 98, “Characteristics ofthe Low Income Population,” Table A-3.) Poverty level income for a famiIy is the ratio of its

total family income to the official poverty threshold for a family of its size and sex of head, expressed as a percentage of the poverty threshold.

Geographic region. –Data are classified by

region of residence into the four major Census

regions: Northeast, North Central, South, and

West. Sample size varies greatly and restricts the

possibility of meaningful analyses by social

characteristics among smaller geographic divisions. The States comprising these four major

geographic regions are:

Northeast North Central

Maine Ohio

New Hampshire Indiana

Vermont Illinois

Massachusetts Michigan

Rhode Island Wisconsin

Northeast–Con.

Connecticut

New York

New Jersey

Pennsylvania

South

Delaware

Maryland

District of Columbia

Virginia

West Virginia

North Carolina

South Carolina

Georgia

Florida

Kentucky

Tennessee

Alabama

Mississippi

Arkansas

Louisiana

Oklahoma

Texas

North Central–Con.

Minnesota

Iowa

Missouri

North Dakota

South Dakota

Nebraska

Kansas

West

Montana

Idaho

Wyoming

Colorado

New Mexiccl

Arizona

Utah

Nevada

Washington

Oregon

California

Alaska

Hawaii

Employ ment.–In addition to their current

employment status, respondents were asked:

<6

. . . Did you ever work for pay?” in various,

specified earlier periods as appropriate. The periods were: before first marriage, since first marriage, between marriage and first birth, ‘between

first and second birth, between second and third

birth, and between the third, and last birth.

Within these periods women were classified as

employed if they worked for pay and not employed if they did not. The rate of nonresponse

to these questions was low, its maximum being

for questions about employment between the

births of the third and the last child. JEmployment status was not ascertained for 3 percent

of women asked about the period, and (duration

of employment was not ascertained for 9 percent. Missing values were imputed.

000

38
APPENDIX Ill

ITEMS ON NSFG QUESTIONNAIRE RELATED TO BREAST FEEDING

SECTIONII

In a study of familygrowth in this country,one of the most importantthingsis kmx!ittg

some basic facts about pregnanciesand births that women have.

Yes . . . (A3KA) . . .. I 10

No .(SK2PTOQ. 21).. 2

A. u: Altogether,how rna”ybabieshave you had born to you,

incIuding●ny who died very young? (Numberof

live bir,h+~ ~%

~, Now I‘d like to get some informationabout (eachof) your (baby/babies).

(ASKA-F FOR EACH LIVE‘BIRTH.)

FIRST

A.

SECOND

When was your (first,second,etc.) child CHILD CHIU

born? (ENTERDATE IN COL. Y OF BIRTH &

PREG. RECORDBETWEENHEAVY LINES.)

B. What did you name the baby? (ENTERIN ..............................

..............................

COL. Z OF BIRTH& PKEG. RECORDNEXT TO ::::::::::::::::::::::::::::::

DATE OF BIRTH.) ..............................

(ENTER C-F IN CHILD COLS. TO RIGHT)

Boy Girl

C. Was that baby s boy or a girl?

Boy Girl

1 2 1 2

1 I

D. How much did (CHILD)weifthatbirth? Lb_ Oz_ Lb_ oz_

E. IF NOT LISTSD IN HOUSEHOLD.ASK:

“/1

I do not have (CHILO)listedin the h.xse Yes[ASK(l)]. 1 Yes[ASK(l)]. 1

hold. Is (he/she)still living? No [ASK(4)].2 No [ASK(4)].2

---- ---- ---- ---- ---- ___ ____ ____ ____

IF h , ASK: Lives here . 1 Lives here . 1

(1) Is this where (CHILD)usually lives Lives some- Lives scmeor does (he/she)live somewhereeIse where else. 2 where ●lse. 2

most of the time?

i

[ASK(2)&(3)] [ASK]

---- ---- ---- ---- ---- -

(2) When did (CHILD)last liv.2 with YOU mm Qm

regular 1y?

---- ---- ---- ---- ____ _

(3) Where is (he/she)livinznow?

(His(her)% hou;ehold . . . . . . ...1 . . . ...1

Long-termcare institution. . . . . ...2 . . . ...2

College/awayat school . . . . . . . ...3 . . . ...3

With other relatives. . . . . . . . ...4 . . . ...4

Other (SPECIFY) . . . . . . . 5 5

rF%r, lS-K7 -------- -------

(4) When did (CHILD)die?

mm mm

F. IF (CHILO)LIVSDWITH MOTHSRAT LEAST

lWO NONTHS. ASK:

(1) When (CHILD)was an infant,did you

{

Yes[ASK(2)J.1 Yes[ASK(Z)].1

breastfecd(l,im/her)at all? No . ...2 No . ...2

----- ----- ----- ----- -

(2) How many weeks old was (he/she)when

you quit breastfeeding (him/her)

altoxcther? RECORDVERBATIMIF R

m m

DOES-NOTANSWER IN “WEEKS.1’

I

.=CKS

I

weeus

I

%-1 Suin.timeswc miss ● baby who died shortlv●fter Yes . . . . . .

THIRD

CHILD

.................

.................

.................

.................

.................

Boy Girl

1 2

Lb oz_

.-=-- ---

140re. . ..l

5+ or less . 2

Don‘,tknow. ~

Yes[ASK(l) ]. 1

No [ASK(L)]. 2

------ --

Lives here . 1

Lives somewhere else. 2

[ASK(2)&(3)]

MQ

. . . . . .

. . . . . . :

. . . . . .

. . . . . . :

5

Qm

Yes[ASK(Z)]. 1

UO . ...2

I I I

Weeks

+&.. (-” ,

birth or never lived at-home. Have we l~cted

all your babiesnow? no . (ASKA) . . 2

A. —.IF NO. How many did we miss?

•1

GO BACK TO Q. 19 AND ASK A-F FOR EACH BABY

MISSED? ENTSR INFOIUCAT20NASOUTMISSEDBABIEs

AND INDICATEPROPERBIRTH ORC&R BY ARROW016

BIRTHAND PKSGNANCYKSCORDAND IN COLLNRISABOVS.

T!?U.S.GOVSRNMSNTPRIN71NGOFFICE , 197S-C-31 1-240 (36)

39
VITAL AND HEALTH STATISTICS Series

Series 1,

Series 2.

Series 3.

Series 4.

Programs and Collection Procedures. –Reports which describe the general programs of the National

Center for Health Statistics and its offices and divisions and data collection methods used and include

definitions and other materiaJ necessary for understanding the data.

Data Evaluation and Methods Research. –Studies of new statistical methodology including experimental tests of new survey methods, studies of vital statisti{-s collection methods, new analytical

techniques, objective evaluations of reliability of collected data, and contributions to statistical theory.

Analytical Studies. --Reports presenting analytical or interpretive studies based on vital and health

statistics, carrying the analysis further than the expository types of reports in the other series.

Documents and Committee Reborts. –FinaI re~orts of major committees concerned with vital dnd

health statistics and documents’ such as recommended mode] vital registration laws and revised birth

and death certificates.

Series 10. Data From the Hculth Jnteruiew Surzey. –Statistics on illness, accidental injuries, disability, use of

hospital, medical, dental, and other services, and other health-related topics, all based on data collected

in a continuing national household interview survey.

.$eriej 12.

Series J 3.

Series 14.

Sf7-ies 20.

Data hr-om the Health Examination Survey and the Health aria’ Nutrition Examination Surzwy. -Data

from direct examination, testing, and measurement of national samples of the civilian noninstitutlonalized population provide the basis for two types of reports: (]) estimates of the medically defined

prev.dence of specific diseases in the United States and tbc distributions of tbe population with respect

t{> physical, physiological, and psychological characteristics ~d (2) analysis of relationships among the

various measurements without reference to an explicit finite universe of jxn-sons.

Data From the Jnstitutiorralized Population Surt,ey.r. L)isi.c)ntil, ued effe, tiy,e 1!175. 1 UIUIC reports t’r<)m

these surveys will be in Series 13.

Data on Health Rcfources [’utilization. - Statistics {>n theu:]iiz:itiorj of health manpower and facilities

providing long-term cam, ambulatory care, hospital care. an[i family planning services.

Data on Health Resources: Manpower and Facilities. St, itistics I>LLthl: numbers, ~eographic, {distribution, and characteristics of bealtb resources including physicians, dentists, nltrses, other he~lth

occupations, hospitals, nursing homes, and outpatient facilities,

Data on .Wortality. --Various statistics on mortallt~ other rl,, uI .is inc iudec! in regular arrnu; ]l,)r m{lnthi~

reports. Special analyses by cause ~f death, Age, and oth<. r {iemngraphic v~ri,~t>lrs, geographic and time

series analvses; md statistics on characteristics of de~ths n(]t ayailat,lc from the vital records based on

sample surveys of chose records,

Series 21. L)alu f~n .Vatal:ly. .}iarri[;g,, a.l~i I)i; f}rcc. \7Jrious st~[is[~{ . {!0 n.i:.d it}, m(irri.~ge, and [iivorcr otl:er

thdn ds m~’ludeti in regui,u annual or monthly rep(jrl$, S\IC>C!Ll analyses t)v ,if’mograp]]ic ‘. :IrI,ible\;

geographic and time series an~lyses; studies of’ fertility; ai:,.i st~tisti~s On charactt.ris:ics IIF births n~,f

a~,ailahle from the vital records [Isscci on sample surveys fIf !ii!>sr rerc}rds.

Series 22. Data F’rom the :Vutiona[ .ilortality and .Vata[ity, .$UYICVS, f) IM’OII!]LIU~d effc(tjv~ I ~)~, .,5 luture rep,)rts

from these sample surveys based in vital records will b; inr]udcd in Series 20 and 21, respectively.

Series 23. Data From the ,Vational Surz,ey of Family (;routh, Statistic5 on iertlllty, famllv f,)rmJ[ioll ~d dls.

solution, family planning, and related maternal and infant health topics derived from a t,ienni~ survey

of a nationwide probability sample of ever-married women 15-44 years of age.

For a list of titles of reports pub~ishecf in these series, write to: >{Lerltifi{ :UId f’ecbni(-al Information Branch

N.~ti[lr]al Crotcr f~~rHealth Statistics

Pul)lic Iiedtb Service

ll~:~ttsviile. Lid. 2078?
NCHS

US DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

P.bl!c Health Serwce

Office of Health Res&mh, Stalmtm, and Technology

National Center for Health Stal,$ t,.,

3700 East Wesl H,ghway

Hyatt$wlle, Mar’ fland 20782

PoSTAGE AND FEES PAID

uS DEPARTMENT OF HEW

HEW 396

THIRD CLASS

)FFICIAL BUSINESS

ENALTY FOR PRIVATE USE, $300

For publicationsm the

Vit.1 .nd Halth St.ttsticr

Series call 301436 NCHS.