)


ANALYTICAL STUDIES	 Series 3 

Number 17 

Patterns of Aggregate 

and Individual Changes 

in Contraceptive Practice 

United States, 1965-1975 

An analysis of aggregate changes in contraceptive methods used by 

American couples in their first marriages over the decade 1965-75 

and an analysis of changes in individual choices of contraceptive 

methods between 1970 and 1975, based on interviews with the 

same women in the two years. 

DHEW Publication No. (PHS) 79-1401 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE 

Public Health Service 

Office of Health Research{Statistics, and Technology


National Center for Health Statistics


Hyattsvilie, Md. June 1979

Library of Congress Cataloging in Publication Data 

Westoff, Charles F. 

Patterns of aggregate and individual changes in contraceptive practice. 

(Vital and health statistics : Series 3, Analytical studies ; no. 17) (DHEW publication ; 

(PHS) 79-1401) 

1. Birth control–United States–Longitudinal studies. 2. Birth control–United States– 

Statistics. 3. Contraception–United States–Longitudinal studies. 4. Contraception–United 

States–statistics. J. Jones, Elise F., joint author. II. Title. III. Series : United States.


National Center for Health Statistics. Vital and health statistics : Series 3, Analytical


studies ; no. 17. IV. Series : United States. Dept. of Health, Education, and Welfare.


DHEW publication ; (PHS) 79-1401.


H0763.6.U5W47 301.42’6’0973 78-31996


For sale by the Superintendent of Docnments, U.S. (3overnment Printing Office 

Wssbington, D.C. 20402 

Stook Number 017-024+3921-1 
NATIONAL CENTER FOR HEALTH STATISTICS 

DOROTHY P. RICE, Director 

ROBERT A. ISRAEL, Deputy Director


JACOB J. FELDMAN, Ph.D., Associate Director for Ana2ysis


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


ROBERT A. ISRAEL, Acting Associate Director for Data Systems


JAMES T. BAIRD, JR., Ph.D., Associate Director for International Statistics


ROBERT C. HUBER, Associate Director for Management


MONROE G. SIRKEN, Ph.D., Associate Director for Mathematical Statktics


PETER L. HURLEY, Associate Directorfor Operations


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

PAUL E. LEAVERTON, Ph.D., Associate Director for Research 

ALICE HAYWOOD, Information Officer 

DIVISION OF VITAL STATISTICS 

JOHN E. PATTERSON, Director


ALICE M. HETZEL, Deputy Director


WILLIAM F. PRATT, Ph. D., Chiej Family Growth Survey Branch


RITA U. HOFFMAN, Chiej Programming Branch


MABEL G. SMITH, chief Statistical Resources Branch. 

Vital and Health Statistics-Series3-No. 17 

DHEW Publication No. (PHS) 79-1401 

Library of Congress Catalog Card Number 78-31996 
FOREWORD


A primary objective of the National Survey of Family Growth-a periodic survey conducted by the National Center for Health Statistics since 19 73—has been 

to monitor the trend and changing patterns of contraceptive use in the United 

States. However, since these are ad hoc surveys based on independent national 

probability samples, the changing distribution of contraceptive methods can be 

monitored only at the aggregate level. Data from the National Fertility Studies 

conducted by Drs. Norman Ryder and Charles Westoff of Princeton University 

provide a valuable supplement to these aggregate analyses. 

It has long been recognized that our understanding of many critical issues in 

fertility research would be greatly enhanced by the incorporation of a prospective 

or longitudinal design in national cross-sectional fertility surveys. Because of repeated interviews at relatively short intervals with the same panel of respondents, 

the longitudinal survey permits the measurement of change at the individual level 

with far fewer problems of recall. Having identified objective changes at two time 

points, the longitudinal design is particularly appropriate for the exploration of 

causal sequences both at the motivational level and in terms of intervening events 

in the respondents’ private lives or in the surrounding community and society. 

Another particularly appealing feature of the longitudinal survey is the opportunity to evaluate the individual’s expectations about future events, measured at 

one interview, as predictors of his or her actual behavior or status as measured in 

a later interview. Although such prospective surveys take significantly longer to 

complete than the more common retrospective surveys, they nonetheless promise 

significantly better control over sources of respondent bias, such as memory limitations or the reevaluation of past events in the light of more recent developments. 

In their 1975 National Fertility Study, Norman Ryder and Charles Westoff, 

study directors for the 1965 and 1970 National FertiIity Studies, have once again 

broken new ground for fertility research. Earlier studies, notably the Princeton 

Fertility Study of 1957 and the Detroit Area Study of 1962, pioneered with the 

application of longitudinal design in fertility surveys, but these were restricted to 

highly selective subpopulations and to very limited geographic representation. The 

1975 National Fertility Study is the first application of the longitudinal design to 

a national sample, although this effort, too, was restricted to a subpopulation: 

that is, continuously married white women aged 15 through 44 years in 1975, 

whose husbands were also married for the first time and whose marriages had 

endured less than 25 years and had begun before the women reached age 25. 

Nonetheless, data from the survey make it possibIe to examine directly many 

issues of measurement reliability, stability of attitudes and expectations, and the 

causes of changes in status between interviews. 
The Center has a keen interest in the contribution of other studies to the 

methodology of longitudinal surveys and to the application of these surveys in 

fertility research. This report deals specifically with the examination of change in 

contraceptive methods at the individual as well as at the more generally measured 

aggregate level; it also reveals some of the measurement problems in studying patterns of change in contraceptive methods. Demographers will look forward to the 

wealth of research findings potential in this rich data source. 

In accordance with Center policy, this report was submitted for peer review. 

The careful review and helpful suggestions of Drs. Gerry Hendershot and Paul 

Placek are gratefully acknowledged. 

William F. Pratt, Ph.D.


Chief, Family Growth Survey Branch


Division of Vital Statistics

CONTENTS 

Foreword ............................................................................................................................................... 

Introduction ........................................................................................................................................... 

Principal Findings ............................................................................................................................. 

Source of Data and Methodology ...................................................................................................... 

Problems of ComparabiKty ............................................................................................................... 

Trends in Aggregate Use ......................................................................................................................... 

The Pfl ............................................................................................................................................. 

Sterilization-Contraceptively Motivated .......................................................................................... 

The IUD .................................................................................................... ...................................... 

The Diaphragm ................................................................................................................................. 

The Condom ..................................................................................................................................... 

Other Methods .................................................................................................................................. 

Trend in Use of Highly Effective Methods ........................................................................................ 

Total Sterilizations-Contraceptive and Noncontraceptive ................................................................ 

Individual Change of Methods ................................................................................................................ 

Incidence and Types of Change 1970-75 ........................................................................................... 

Changes in Method and in FertiMy Intentions .................................................................................. 

Sources of Method Changes .............................................................................................................. 

Pregnancy and Change in Methods .................................................................................................... 

Summary .................................................................................................................................$.............. 

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

Lkt of Detailed Tables ........................................................................................................................... 

1. 

2. 

3. 

LIST OF TEXT FIGURES 

Percent of women using contraception, by method and whether additional births were intended:


currently married women 1544 years of age, both spouses married once, 1965, 1970, 1973,


and 1975 ............................ ....... ...... ..................................................................................


Percent of women who were surgically stefilzed or whose husbands were sterilized: currently


married women 1544 years of age, both spouses married once, 1965, 1970, 1973, and 1975 .....


Method of contraception used in 1975 by method used in 1970 among currently married white 

women, both spouses married once, 1970 and 1975 ..................................................................... 

# 

... m 

1


1


: 

4


5


6


6


6


6


7


7


7


8


8


9


10


11


12


12


13


5


7


9


v

SYMBOLS 

Data not available——————— ..-

Category not applicable——— . . . 

Quantity zero-—–-——---–-—— 

Quantity more than O but less than 0.05— 0.0 

Figure does not meet standards of 

* reliabilityy or precision— 
PATTERNS OF AGGREGATE


AND INDIVIDUAL CHANGES


IN CONTRACEPTIVE PRACTICE


Charles F. Westoff and Elise F. Jonesa 

INTRODUCTION 

In 1975, an estimated three of every four 

married couples using contraception were sterilized, on the pill, or using an intrauterine device; 

a decade earlier this figure was only somewhat 

more than a third. The first part of the following 

account contains a description of that extraordinary development. It includes the first data 

published from the 1975 National Fertility 

Study (NFS)b along with comparisons from the 

1965 and 1970 NFS and the .1973 National 

Survey of Family Growth (NSFG).C The second 

part of the report exploits the reinterview design of the 1975 NFS and analyzes patterns of 

aCharles F. Westoff is Director of the Office of Population Research and Professor of Demographic Studies 

and Sociology at Princeton University. Elise F. Jones is 

a Research Assistant at the Office of Population Research and a doctoral student in demography at the University of Pennsylvania. 

bThe 1975 as well as the 1965 and 1970 National 

Fertility Studies were directed by N. B. Ryder and C. F. 

Westoff of the Office of Population Research, Princeton 

University, under contract with the Center for Population Research of the National Institute of Child Health 

and Human Development. 

cThe 1973 National Survey of Family Growth was 

conducted by the National Center for Health Statistics. 

The procedures used to select the sample, estimate population parameters, and estimate sampling variances can 

be found in the “The National Survey of Family Growth 

Cycle I: Sample Design, Estimation Procedures, and 

Vmiance Esfiation.” 1 Substantive results are published 

in Series 23 of the Vital and Health Statistics series. 

change in individual contraceptive practice over 

the 5-year interval from 1970. 

Principal Findings 

At the aggregate level, this report documents 

a continued increase in the proportion of married couples currently using contraception and a 

continued decline in the proportion that have 

never used contraception. Although “the pill” 

remains the most popular method of family 

planning among white women married less than 

10 years, there is evidence of a decline among 

couples in the longer marriage duration categories. 

The main challenge to the pill comes from 

the increasing popularity of surgical sterilization, which is now clearly the most commonly 

used method among couples married 10 years or 

more. Its rapid adoption in the last few years 

suggests that sterilization of one kind or another 

(including sterilizing surgery for medical reasons 

only) may now be the most common barrier to 

conception among married couples of reproductive age. Three-quarters of the couples using 

contraception are now using the three most 

highly effective methods: sterilization, the pill, 

or the IUD (intrauterine device). 

At the individual level, about half of the 

women reinterviewed were using a different 

method in 1975 than in 1970. Most method 

changes were to sterilization which has between 

two and three times the drawing power of its 

nearest competitor, the pill. Beyond these two 

1

methods, only the condom and the IUD show 

any appreciable appeal to those using other 

methods. Changes in method are more likely to 

occur in the transition between the period during which contraception is used to delay the 

birth of the next child and the period after 

desired family size is reached when contraception is used to avoid further pregnancy. However, among those who have not already been 

sterilized, changes in contraceptive methods 

were equally likely after no more children were 

desired. 

Those who reported an unplanned pregnancy during the 1971-75 period were more 

likely to change methods than those who reported either no pregnancy or a planned pregnancy. 

Sources of Data and Methodology 

The 1975 National Fertility Study is based 

on data collected from a national probability 

sample of continuously married white womend 

who met the following additional qualifications: 

duration of marriage was less than 25 years, age 

at marriage was less than 25 years, and the husband was also married only once. For durations 

of marriage over 5 years, the sample consisted 

of eligible women selected from the 1970 NFS 

sample who were thus reinterviewed after an 

interval of approximately 5 years. A proportionate sample of new respondents was added to 

represent marriages that occurred after 1970. 

From the total 1970 NFS sample, 3,226 

women appeared to be eligible for reinterview 

on the basis of their status in 1970. Of these, 

401 proved to have become ineligible in the 

interval due to dissolution of their first marriage. 

The remaining 2,825 respondents made up the 

target population for the 1975 reinterview. This 

wfi successfully carried out for 2,361 women 

‘Black women were reluctantly excluded from the 

reinterview because the original 1970 sample of black 

women indicated serious biases and the numbers in each 

5-year marriage cohort would have been too small for 

many analyses. The decision to confine the analysis to 

intact first marriages was made in the light of our emphasis in the 1975 study on causal analysis rather than 

on parameter estimations for the total population. Moreover, women not currently married or in second marriages would not be represented in sufficient numbers to 

permit separate analysis. 

representing 83.6 percent of the total; 12.5 percent refused to be reintemiewed (perhaps 1.5 

percent of whom would have been ineligible), 

and the remainder could not be located or in a 

few cases were unavailable for other reasons. 

The new sample of women married after 

1970 numbered 1,042. Together with the 

women successfully reinterviewed, the total sample size thus consists of 3,403 respondents. 

As might be anticipated, the women successfully reinterviewed were unrepresentative of the 

original target population in a number of respects. The probability of successful reinterview 

was negatively related to marriage duration and 

positively related to education; Catholics and 

women intending to have no more births were 

less likely to accept reinterview than nonCatholics or women intending more births. Each 

of these background variables is recognized to 

have some impact on contraceptive practice. 

Furthermore, exposure status itself in 1970 

shows a relation to the probability of successful 

reinterview which was to some degree independent of the above characteristics; those who were 

not using contraception and were neither sterile 

nor pregnant, postpartum, or trying to get pregnant in 1970 were less likely than others to be 

successfully reinterviewed; women using the 

more effective contraceptive methods were 

somewhat overrepresented among the completed 

reinterviews, especially at longer durations of 

marriage. 

Recognizing the implications of such bias for 

estimates of contraceptive practice in 1975, an 

attempt was made to standardize the 1975 data 

to reflect the composition of the entire target 

population with respect to the most important 

characteristics. This procedure could be justified 

on the assumption that within any subgroup, 

women who were missed would have changed 

(or not changed) their exposure status between 

1970 and 1975 according to the same pattern 

as those successfully reinterviewed. However, no 

combination of characteristics was found that 

produced substantial differences between the 

standardized and unstandardized distributions. 

Ultimately, the decision was made to standardize the 1965, 1973, and 1975 exposure distributions on the 1970 distribution by duration 

of marriage. This represents a significant step 

toward reduction of the bias due to failure to re2 
interview all of the eli~ble respondents in 1975. 

It also eliminates the effects of changes in marriage duration across the decade, thus facilitating 

a description of time trends in contraceptive 

practice. 

The primary comparisons of 1975 estimates 

are made with data drawn from the 1965 and 

the 1970 National Fertility Studies.e To supplement these bodies of data as well as to provide 

a picture of any more recent changes in contraceptive practice, some tabulations have also been 

included from the 1973 National Survey of 

Family Growth,f which was also based on a national probability sample of women of reproductive age. For purposes of comparison with 

1975 estimates, the samples from these other 

studies were reduced to white women married 

less than 25 years married only once, at less than 

25 years of age, with husbands who have also 

been married only once. Correspondingly, 

women over age 44 have been eliminated from 

the 1975 sample, reducing the final sample size 

to 3,329 women. 

Problems of Comparability 

Because these studies were conducted at 

different times, and in one instance by different 

investigators, there are the inevitable problems 

of comparability of measurement both in the 

wording of questions and in the classification 

systems adopted. We are fairly confide~t that 

comparable procedures were followed in the 

collection of data about contraceptive methods 

currently used. If more than one method was reported in combined use, it was classified according to a rule that gave first preference to contraceptive sterilization, second to the pill, then the 

IUD, diaphragm, and condom in that order. 

Multiple methods that did not involve these 

were classified in a residual “Other methods” 

category. 

Comparisons of the proportions classified as 

sterile (for reasons other than contraception) 

suggest a rapid decline between 1970 and 1975 

which probably reflects mainly measurement 

problems rather than a genuine decline. A major 

‘The 1965 NFS was the basis of a book by N. B. 

Ryder and C. F. Westoff;2 the 1970 NFS was reported 

by C. F. Westoff and N. B. Ryder.3 

‘The most relevant publication from this study is 

by Kathleen Ford in a monthly vital statistics report.4 

problem of comparability lies in the classification of couples as noncontraceptively sterile. 

Over the years, we have gravitated toward a 

series of simple questions about whether the 

woman thought it would be possible to conceive 

or not if she wanted to have another child. 

Those who stated that it was impossible and 

who were, therefore, considered to be sterile included women who reported either surgery with 

contraceptive or noncontraceptive intent, or 

who had other nonsurgical reasons for reaching 

that conclusion. In 1975, the questionnaire also 

provided for the first time the prior possibility 

of specifying sterilization as the current method 

of contraception, and those who did so were 

not asked further about sterility. There are thus 

two problems of measurement: (1) the consistency with which a sterilizing operation is classified as contraceptive or not and (2) how well 

the reports of nonsurgical sterility in 1970 conform with the same self-classification 5 years 

later. There is evidence from the reinterviewed 

sample that a large fraction (56 percent) of respondents who reported in 1970 that they had 

had a noncontraceptive sterilizing operation 

indicated in 1975 that the operation had been 

for contraceptive reasons. The option of giving 

sterilization as the method currently being used 

very likely contributed to reclassification in this 

direction. There was considerably less movement 

in the opposite direction. This suggests unreliability of measurement on the one hand, but 

also, no doubt, reflects the rapidly growing 

social acceptability of the contraceptive procedure. The reinterview design also permits an 

evaluation of the reliability of self-classification 

of nonsurgical sterility by examining the 1975 

status of the same couples who in 1970 reported 

that it was impossible to conceive for such reasons. There were 60 such couples in 1970 of 

whom only 61.7 percent were so classified in 

1975. The remainder are distributed among 

women who in 1975 report that they are trying 

to get pregnant, are pregnant, have had a noncontraceptive operation (not necessarily inconsistent), are using various contraceptive methods, and so forth. 

In addition to these problems, the 1973 

NSFG used a different set of questions to establish sterility and subfecundity. Because of problems in trying to redefine categories to maximize 

3 
comparability, it was finally decided that it was 

unwise to maintain any more detailed distinction among nonusers of contraception than that 

between the category “Pregnant, trying to get 

pregnant, postpartum, “ in which we have some 

confidence, and all other categories of nonuse. 

The residual ca;egory thus includes surgical 

sterility for noncontraceptive reasons as well as 

other functional sterility and sub fecundity. It 

also includes presumably fecund couples who 

are not using contraception for various reasons 

including religious and esthetic objections, indifference, anxiety about side effects, ignorance, 

and very Iow coital frequency. The total proportions surgically sterilized (for any reason) that 

can be regarded as a minimal value of the general 

incidence of sterility in the married population 

have been estimated for 1965, 1970, 1973, and 

1975. But for the main analysis, only the two 

designated types of noncontraceptive exposure 

are delineated. 

TRENDS IN AGGREGATE USE 

There appears to have been a substantizd increase in the (standardized) total proportion currently using contraception, an absolute increase 

amounting to 11.4 percentage points since 1970 

and 6.1 since 1973 (table 1). This seems like a 

large increase over a short period of time. Can 

any of it be attributed to measurement error or 

sampling bias? 

Some part of the increase is spurious because 

of the measurement problem referred to earlier, 

that a considerable number of women who had 

been sterilized prior to 1970 reported the operation as noncontraceptively motivated in 1970 

but 5 years later said that it had been performed 

for contraceptive purposes. The net statisti~~ 

effect of this reclassification is that an additional 

1 percent of the sample should have been classified as contraceptively sterilized in 1970 rather 

than as noncontraceptively sterile, which would 

have the consequence of reducing the overall 

increase in contraceptive practice to 10.4 percentage points. 

The former residual category “Other nonusers, ” now combined with the noncontraceptively sterile, also showed a suspiciously large decline—from 9.5 percent in 1970 to 4.0 percent 

in 1975. The decline in this category appears to 

be mostly genuine, but is probably somewhat 

exaggerated because of the disproportionately 

greater refusal of women to be reinterviewed 

who were so classified in 1970. (This stems 

paftly from the associated underrepresentation 

of less educated and Catholic women.) 

As in the case of some sterilization operations now being classified as contraceptive rather 

than purely medical in intent, there may be a 

tendency toward more admission of contraceptive practice in general, which would have had 

the effect of understating contraceptive practice 

in 1970 and earlier, thereby exaggerating the increase between 1970 and 1975. This would also 

show up primarily in the “Other nonusers” 

category. 

Overall, then, the 1975 estimates appear to 

relate to the 1970 figures in a reasonable way. 

Adding the 1973 estimates from the National 

Survey of Family Growth strengthens this interpretation. (The 1973 interviews were actually 

centered just 3 months later than the point equidistant in time between the 1970 and 1975 

interviews.) The (standardized) proportions 

“Pregnant, trying to get pregnant, postpartum” 

declined from 15.0 percent in 1970 to 13.1 percent in 1973, to 12.0 percent in 1975. The proportions classified as “Sterile and other nonusers” declined from 17.5 percent in 1970 to 

14.0 percent in 1973; to 9.0 percent in 1975. 

In conclusion, the overall increase of 11.4 

percentage points in the proportion currentIy 

using contraception from 1970 to 1975 might 

be exaggerated by as much as 2 percent because 

of redefinitions of sterility and because of bias 

in the sample of reintemiews. It is only the latter 

that would affect the 1975 statistic directly, 

however, so this view, if correct, would place 

the proportion of white women currently married and married only once, currently using contraception at 78 percent (standardized). 

The increase in contraceptive use between 

1973 and 1975 is concentrated entirely in the 

category who “Intend no more births” (table 1 

and figure 1), and most of it has occurred among 

couples married for 15 to 24 years (table 2). 

Combined with substantial increases in proportions using the most effective methods, this 

4 
100 

-

76 

$ 

8 60
 K


i+!


26 

0 

1975 1973 1970 1965 1975 1973 1970 1965 

Intend more Intend no more 

FuTuRE BIRTH INTENTIONS 

Figure 1. Percent of women using contraception, by method 

and whether additional births were intended: currently 

married women 15-44 years of age, both spouses married 

once, 1965, 1970, 1973, and 19751 

increase in contraceptive practice among couples 

in the later stages of their reproductive lives “no 

doubt implies a significant reduction in unwanted births. Furthermore, the increase in contraceptive practice has been greater among the 

least educated women (table 3). As a result, the 

positive association between proportions using 

contraception and education has all but disappeared, and the disproportionate share of 

unwanted pregnancy at the low end of the socioeconomic scale should likewise diminish. 

The foregoing estimates relate to cuwent 

use of contraception. There has also been a considerable decline in the proportion of continuously once-married white women who have 

never used contraception, from 14.3 percent in 

1965 to 12.2 percent in 1970, 9.6 percent in 

1973, and down to 5.3 percent by 1975 

(table 4). Considering the fact that a substantial 

proportion of those who have still never used a 

method are recently married (about one-third in 

1975 were married less than 5 years), the final 

proportion of recent cohorts that will go 

through marriage without ever using contraception will be low. 

Table 5 presents an historical cohort series 

of contraceptive use utilizing the 1955 and 1960 

Growth of American Family (GAF) surveys and 

the 1965, 1970, and 1975 National Fertility 

Studies. In addition to the sample Imitations 

already discussed, it was necessary to confine 

this tabulation to women 18-39 years of age because of the 1955 GAF Study sample design. 

The decline in the percent who have never 

used contraception is clear and consistent across 

cohorts and has reached a very low level indeed: 

The cohort of white women married in 1966-70 

shows only 2.1 percent of women whose pregnancy histories reveal no use of contraception 

through 5-9 years of marriage, and among the 

newest cohort, women married in 1971-75, only 

5.2 percent are so classified over an average marriage duration of 2.5 years. (There is one anomaly in table 5 in the cohort of 1951-55 at duration 15-19 years.) 

The Pill 

Among once-married, white women, the pill 

remains the most popular method of birth control in 1975, but its predominance is being 

threatened by sterilization. Now, only among 

women married less than 10 years, is the pill the 

most widely used method. In fact, 1975 data 

suggest the beginnings of a decline in the use of 

the pill which may have begun as early as 1973 

in some marriage duration categories (5-9, 10-

14 years). The overall movement is so slight– 

from 35.4 percent of use in 1970 t 35.5 percent in 1973 to 34.3 percent in 1975 (table l)– 

that one might more reasonably infer stabilization rather than decline, but there is evidence of 

a significant decline at marriage durations over 

15 years. 

Another perspective on the same question 

can be obtained from the tabulation of contraceptive methods by whether the women intends 

additional childbearing (table 1). Among women 

who intend more births, the proportion using 

the pill continues to increase and completely 

dominates contraceptive practice; among women 

who intend no more births, there has been a 

clear decline in pill use from 1970. Evidently the 

pill has continued to be strongly attractive to 

younger women in the early stages of family 

formation, but in recent years their older counterparts, when faced with a long period of ex5 
posure to the risk of childbearing after the birth 

of the last wanted child, have turned to other 

methods. Use of the pill shows no particular 

association with education by 1975 (table 3). 

Roughly one-third of women using contraception at each educational level have elected this 

method. 

Sterilization–Contraceptively 

Motivated 

By 1975, the (standardized) proportion of 

white couples using contraception who are sterilized (31.3 percent) is only 3.0 percentage 

points below the proportion using the pill (34.3 

percent). The increase in reliance on contraceptive sterilization has been dramatic even over 

the short period since 1973. At marriage duration 20-24 years, it increased from 37.0 to 55.7 

percent; at duration 15-19 years from 32.0 to 

51.6 percent; and at duration 10-14 years from 

30.4 to 43.3 percent. It is now the single most 

popular method for couples married 10 years or 

more. Among couples who have had all the 

children they want to have, sterilization clearly 

dominates the field by 1975 :43.5 percent compared with its nearest competitor, 24.1 percent 

taking the pill. Relief from the necessity for 

continuous practice of contraception is surely 

one motive for sterilization, however, its increasing popularity also implies that couples are 

more willing to accept irreversibility of the decision to terminate childbearing. This appears to 

represent yet another step in the long-term trend 

toward rationalization of the childbearing 

process. 

Male and female procedures are still equally 

attractive. Since 1973, female sterilization 

appears to be increasing somewhat more rapidly, 

perhaps because of the availability of laparoscopy, a new and relatively simple procedure. 

Female sterilization continues to be less popular 

among more educated women (table 3) than 

among the less educated, but since 1$170, 

vasectomy has been equally popular across educational categories. 

The IUD 

Use of the IUD, which increased sharply between 1965 and 1973, appears to have declined 

between 1973 and 1975. Only among women 

married as long as 20-24 years who are least 

likely to intend further childbearing is there 

actually some indication of a continued increase 

in the use of the IUD. As in the past, there is 

also a slightly higher probability that women 

with higher education will use the IUD. 

The Diaphragm 

There has been speculation recently, supported by drug company inventory reports, that 

the diaphragm is making a comeback and is 

appealing to younger women who are averse to 

taking the pill for long periods of time. Our 

overall aggregate trend data show no obvious 

support for this hypothesis: They show a continued decline from 5.7 percent of users in 1970 

to 4.0 percent in 1973 and 3.9 percent in 1975. 

However, a possible countertrend does appear 

among women who intend to have more births. 

In this category, the proportion of users relying 

on the diaphragm (which had been declining between 1965 and 1970) appears to have reached a 

low point of 3.6 percent in 1973 and then increased again to 4.2 percent in 1975. Among 

women intending no more births, the proportion 

using the diaphragm continued to decline to a 

level of 3.7 percent in 1975. Thus it appears that 

there may be some basis for assuming that the 

diaphragm is enjoying a resurgence of popularity, but for the present it is used primarily 

among young women who are utilizing contraception for spacing purposes. 

The direct relationship between use of the 

diaphragm and education that has been observed 

in past years persists even at the very low levels 

of use in 1975. 

The Condom 

Use of the condom continues to decline. 

Between 1965 and 1975, its use has dropped by 

half. The only apparent exception to this generalization is among recently married couples; 

at marriage durations O-5 years there has been an 

increase since 1970 and at durations 5-9 years 

there is at least a suggestion of greater use since 

1973. Whether this exception indicates the 

beginning of a reversal of the kind suggested by 

the diaphragm remains to be seen. 
! 

I 

Other Methods 

The proportions relying on all remaining 

methods—withdrawal, foam, rhythm, douche— 

have all declined with the possible exception of 

the residual category labeled “Other methods” 

(which includes some multiple method usage as 

well as other single methods). The rhythm 

method now accounts for only 2.8 percent of all 

use and the duration-specific proportions (table 

2) indicate the lowest proportions among the 

most recently married categories suggesting that 

the decline may still not be finished$ 

Collectively, these four methods plus the 

residual “Other methods” category now account 

for only 11.0 percent of total &.e.-

Trend in Use of Highly Effective 

Methods 

About three-quarters of married couples currently using contraception are using highly effective methods–sterilization, the pill, or the IUD. 

A decade earlier, in 1965, this (standardized) 

percent was 38.3. It climbed to 56.9 percent in 

1970, to 67.0 percent in 1973, and in 1975 

reached 74.3 percent. A similar pattern appears 

at each marriage duration with the most dramatic increases evident at the longest. durations 

(see table 6). Although in the past there was a 

striking pattern of the most effective methods 

being used more by the most recently married 

couples, this has diminished over time; by 1975 

there is little variation in use of highly effective 

contraception by marriage duration. 

In order to see the intra- and intercohort 

changes more clearIy, table 7 was prepared for 

the 1965,1970,and 1975 studies (1973 is excluded because it does not fit into the 5-year 

groupings). The column comparisons show, 

within each marriage duration, the tremendous 

intercohort increase in the use of the most effective methods. The diagonal row values show the 

pattern of appreciable intracohort change which 

would be expected. 

gFor a discussion of religious differences in contraceptive practice, see reference 5. 

Total Sterilizations–Contraceptive 

and Noncontraceptive 

In any population of couples of reproductive 

age there is a certain incidence of sterility that 

results from surgery performed for reasons of 

pathology, medical in intent but contraceptive 

in consequence. The combined incidence of 

medically and contraceptively motivated operations must by now have reached a considerable 

level in view of the recent significant increases 

in the proportion of couples electing surgical 

sterilization at least partly for contraceptive reasons. It should be emphasized that such perceptions are subjective and not highly reliable. The 

interview data revealed a distinct tendency for 

women who in 1970 reported operations for 

medical reasons only to report these same operations in 1975 as for partly contraceptive reasons. 

Moreover, there can be obvious ambiguity in 

instances where pregnancy would be contraindicated on medical grounds. For these reasons, in 

table 8 estimates have been assembled by marriage duration of the proportion of couples 

surgicaUy sterilized for any reason at each duration of marriage. 

The most recent estimates (for 1975) indicate that more than a quarter of white couples 

(either wife or husband sterilized) at all durations of marriage combined have been surgically 

sterilized (figure 2) and that nearly half (47 percent) of all white couples married 10 years or 

more are now sterilized. These should be taken 

30


20


k


z 

; 

& 

10 

0


1975 1973 1970 lee5


1 Based o. dam m table 8. Percents standard ized.. 1970 manias d.rauon d,strib.tton. 

Figure 2. Percent of women who were surgically sterilized or 

whose husbands were sterilized: currently married women 

1544 years of age, both spouses married once, 1965, 1970, 

1973, and 19751 

7 
as low estimates of infecundity in the total 

population for two reasons: (1) They reflect 

only surgical sterilization, thereby excluding 

couples who cannot conceive or carry a pregnancy to term for a variety of other nonsurgical 

reasons; (2) they exclude categories other than 

white, once-married couples, and earlier studies 

have shown ,tiat black persons have a higher 

incidence of infecundity resulting both from 

mediczd and contraceptive reasons. The trends 

indicate major increases in surgical infecundity 

between 1970 and 1975 for alI three operations 

specified. Increases in tubal Iigations and vasectomies but not - “in hysterectomies are also 

evident at each duration between 1973 and 

1975. 

INDIVIDUAL CHANGE OF METHODS 

Thus far, only changes in contraceptive practice have been examined. However, two features 

of the 1975 NFS permit investigation of individmd changes in methods. The longitudinal design 

of the study makes possible comparison of a 

respondent’s status in 1970 with her status in 

1975, thereby permitting answers to such questions as: What proportion of couples do change 

methods? Which methods do they abandon and 

which are they most likely to continue to use? 

Is there a pattern of change associated with the 

shift in intention of use from timing pregnant y 

to avoiding further pregnancy? In addition, a 

month-by-month calendar covering the respondent’s fertility and contraceptive history for the 

1970-75 period can be used to study a further 

series of questions: Do couples who experience 

an unplanned pregnancy tend to change methods more than others? What methods were being 

used at the time coupIes eIected sterilization? 

These questions are taken up in turn in this 

section. 

Incidence and Types of Change, 

1970-75 

The cross-classification of exposure status in . 

1970 by exposure status in 1975 for all respondents IS displayed in table 9. It includes 

changes between noncontraceptive and contraceptive exposureh as well as interchanges among 

methods from 1970 to 1975, but intervening 

changes during the period are not represented in 

this table. Since the various categories of nonuse 

can be viewed for the most part as alternate 

phases for women who would otherwise be using 

contraception, our attention can be limited to 

the patterns of change among couples who were 

using methods at both times (tabIe 10). Both 

tabIes are Iimited, of course, to women who 

were interviewed in both years and had, therefore, been married at least 5 years by 1975. 

The proportion of coupIes using the same 

method in 1975 that they were using in 1970 

ranged from the obvious 100 percent for those 

surgically sterilized to a low of 22-23 percent 

for those using foam or rhythm. The loyalty 

associated with the pill, the IUD, the diaphragm, 

and the condom is about equal; an average of 

around 46 percent of those using these methods 

in 1970 were a.ko using them in 1975 (figure 3). 

The number of women using other methods is 

not large in either year, but changes among 

such methods would appear as no change in this 

tabulation. Thus an overall minimum estimate of 

49.6 percent using a different method in 1975 

from that used in 1970 can be obtained. 

Roughly the same proportions changed from 

each method to sterilization, ranging from a low 

of 26.5 percent of women using rhythm in 1970 

to a high of 39.2 percent of women using foam. 

Thus there is no indication that couples who 

have previously relied either on the more effective or on the less effective methods of contraception are particularly likely to move on to 

sterilization. Differences in the proportions of 

couples electing the male as opposed to the femaIe procedure are also small excepi for those 

formerIy using the IUD who show a decided 

preference for the female procedure. 

Aside from the decision to be sterilized, 

which dominates the pattern of change, the 

hFor this analysis, all women who had had a sterilizing operation and reported that it was for contraceptive 

reasons in either 1970 or 1975 were classified as contracep~ively sterile. 

‘One woman was either in error in reporting that 

she had been sterilized in 1970 or could have had a tubal 

ligation reversed. 

8 
------ ----- ----

phragm, 2.2 percent; and rhythm, 1.6 percent. 

Thus sterilization would appear to have between 

two and three times the drawing power of the 

pill (with the important caveat that the implication of sterilization is significantly different as 

discussed in the previous section). The pill, in 

turn, has twice the attraction of the condom 

6.6% and the IUD, the only methods that hold any 15.0% appreciable appeal for couples already using 

some form of contraception. 

uSING THE Changes in Method and in Fertility PILL IN 1970 

intentions 

% 

Earlier aggregate comparisons have shown 

2.s% that whether couples are using contraception to 

USING THE 11.8% delay an intended birth (delayers) or to termi­ cONDOM 

IN 1970 � Pill	

nate fertility after having achieved or exceeded 

their desired family size (terminators) makes a -46.1% � Wife sterilizecl difference both in the methods used and in the 

:::::. 1. 6.711% ID Husbandserilized efficacy with which they are used. When the uSING THE 23.4% ‘:! i IUO IN 1970 & 10.9?% � Other intention is timing, the preferred method is the 10.9% 

15.7% H I Condom pill; when the intention is termination, the pre- 22.6% .;;; ‘J 

::: 22.6% H I luo ferred method is sterilization. These differences USING FOAM 21.6%@ .: IN 1970 17.6% H ,0,.	 are also evident in the distributions of changes 

among methods shown in table 11. Here the re1Dwxi WI da(a in Iablc 10. Women were marled before age 2S, and only marital dur?.t[.amof 5.24 yur: interviewed respondents have been divided into wre In.1.ded, three broad categories according to their fertility 

intentions at each interview: those who intended 

more births at both times, those who intended 

Figure 3. Method of contraception used in 1975 by method more in 1970 but had reached the stage where used in 1970 among currently married white women, both 

spouses married once, 1970 and 19751 

/ 

they intended no more by 1975, and finally 

those who already had intended no more by 

1970 and gave the same response in 1975.j The 

main interest at this point is in whether there is 

most likely change was to the pill. With the more change of methods during the stage when 

. exception of rhythm users in 1970 who are intentions change and whether the different 

quite widely scattered among users of all meth- intentions categories show distinct patterns of 

ods in 1975, proportions shifting to the dia- change. 

phragm, condom, rhythm, foam, or other meth- The percent of women who changed methods are negligible. ods in each of the three categories provides a One indicator of the relative attractivenec~ crude index of the amount of change. The eviof each method is the proportion shlttmg to that dence does support the hypothesis that change 

method among couples who were eligible to in intentions increases the probability of changhave made such a shift, that is, those who were ing methods. The greatest change in methods 

neither sterilized nor already using the method (60.5 percent) occurs among those who also 

in 1970. These figures in order of importance 

are: sterilization, 32.1 percent (female, 16.3 

percent; male, 15.8 percent); pill, 13.2 percent; jFour women who sfid they intended no more births 

condom, 6.0 percent; IUD, 5.2 percent; other in 1970 but intended more in 1975 are omitted from 

methods, 3.5 percent;. foam, 2.5 percent; dia- this analysis. 

9 
changed their intentions, that is, those who completed their intended fertility during the 5-year 

period. This compares with 50.9 percent changing methods among those who intended more 

births at both times and 46.0 percent among 

those who intended no more births at both 

times. 

Those who intended more births at both 

times were, of course, heavily concentrated 

among young women who had been married 

only recently as of 1970. The pill was the only 

method used by this group in sufficient numbers 

in 1970 to show change to other methods, and 

it is worth noting that scarcely more than half 

of those using the pill in 1970 were still using it 

5 years later even though their intention status 

had not altered. 

As previously mentioned, most changes of 

method occurred among women who were delayers in 1970 and terminators by 1975. Within 

this group, half of those using the pill in 1970 

were using some other method in 1975, but this 

represented less change than for any other 

method. Although the base number is too small 

to draw a definite conclusion, it would appear 

that the rhythm method was abandoned by proportionately more women than any other 

method. Foam was also given up by a large fraction (76.9 percent). More than 1 of 4 women in 

this intention category elected sterilization during the period; a somewhat smaller fraction 

(22.2 percent) of those for whom a switch to 

the pill was possible actuaUy chose this method. 

The likelihood of moving to sterilization or the 

piIl varied somewhat among users of different 

methods, but no particular patterns are discernible. 

Even among those who were using contraception in order to avoid any further childbearing at least as far back as 1970, there was considerable change, although less than within the 

other intention categories, largely because 22.0 

percent of this group were already sterilized as 

of 1970. Among those who were theoretically 

eligible to change methods (women who were 

using nonsurgical methods in 1970), 58.9 percent actually shifted, a proportion very similar 

to that shifting among those whose intentions 

changed from delay to termination. The proportions using the same method in 1975 as in 1970 

do tend to be a little higher for this group than 

for those whose intentions changed (especially 

in the case of rhythm) with the exception of the 

pill for which the indicated level of acceptance 

is somewhat lower. Greater stability is what 

would be expected under the hypothesis, but in 

the case of the pill this may have been offset by 

adverse publicity especially concerning its continued use by older women. The proportion 

electing sterilization is distinctly higher for most 

methods, and, overall, 38.5 percent of the 

women to whom this choice was available became sterilized. The female operation was preferred not only by women who were originally 

using the IUD but also by women starting with 

the diaphragm, whereas male sterilization was 

more likely among couples who were using the 

condom. These observations provide the only 

real suggestion in these tables of sex-linked 

patterns of contraception. 

In conclusion, the shift in intentions that 

occurs when the number of intended births has 

been reached is associated with a significantly 

higher probability of changing methods of contraception than occurs during the family building stage itself. The fact that proportions 

electing sterilization are higher when some time 

has elapsed following the shift in intention from 

delay to prevention suggests that unplanned 

pregnancy may also be a factor in patterns of 

change, q question that is discussed next. 

Beyond the gradual gathering of momentum 

toward sterilization, however, the successive fertility intention stages are characterized by essentially similar patterns of method change. d 

Sources of Method Changes 

The foregoing analysis of individual changes 

in methods was addressed primarily to the 

measurement of the probability of change from 

one method to another among couples currently 

using contraception both in 1970 and in 1975. 

Restriction to this 5-year period has two disadvantages: It obscures other changes that might 

have occurred during the intervening years, and 

it is confined to couples married at least 5 years, 

thus excluding the experience of the more 

recently married women. To overcome these 

10 
shortcomings, the method used prior to the 

most recent method for all couples who changed 

methods during the past 5 years has been reconstructed from the contraceptive histories collected in the 1975 NFS. The primary interest 

here is to examine the methods used prior to the 

last change, more specifically, to obtain another 

view of what couples were using before they 

were sterilized. 

The results are shown in table 12. This tabulation indicates that the pill is the primary 

source from which couples changing methods 

between 1971 and 1975 originated, which is not 

surprising in view of the extent of use of the pill. 

More than half of the couples changing methods 

who did not elect sterilization formerly used the 

pill. 

Couples currently sterilized are drawn less 

from the pill than from all other methods combined. Sterilized couples are also less likely to 

have been using the pill compared with couples 

who switched to methods other than sterilization. There is a greater tendency for couples 

~,ho eIected fem~e sterilization to have been 

using the IUD than for couples who elected male 

sterilization, but the reverse is true with the 

condom. Thus, from this perspective, there is 

again some evidence of sex-linked patterns of 

change. 

Pregnancy and Change in Methods 

It seems plausible that a change in methods 

could be occasioned by an unplanned pregnancy. Although there are many other reasons 

why couples may change methods, unsuccessful 

use should rank high on the list. 

In order to establish a connection between 

pIanning failure and a change in methods, it was 

necessary to consider couples who were exposed 

to the risk of changing methods. Exploitation of 

the month-by-month calendar of contraceptive 

usc from 1970 to 1975 included in the 1975 

interview meant that the analysis also reflected 

recent experience. 

Certain categories of experience were excluded: couples who had been married less than 

30 months and intervals without a pregnancy in 

which there was not continuous use of contraception for at least 30 months (in both cases a 

more or less arbitrary cutoff duration to exclude 

those with little exposure to the possibility 

either of pregnancy or of method change); also, 

pregnancies which were not both preceded (for 

unplanned pregnancies within 6 months) and 

followed (within 4 months) by contraceptive 

use. Some women reported more than one pregnancy which met the qualifications; all such 

pregnancies were included in the analysis. Contraceptive sterilization was treated as a method 

throughout. 

The results &e presented in table 13, which 

has several noteworthy features: 

Changes of method were reported for a substantial fraction (37.2 percent) of women 

without a pregnancy. This merely substantiates the obvious fact that there are other 

reasons for change. 

The percent that changed methods among 

couples with no pregnancy during the period 

(37.2 percent) was about the same as the 

percent that changed methods after experiencing a planned pregnancy (38.4 percent). 

This is the anticipated result, since a couple 

that deliberately interrupted the use of a 

method in order to become pregnant would 

not be expected to change methods because 

of the pregnancy. 

As hypothesized, the proportion who 

switched to another method after a pregnancy was higher among those who reported 

an unplanned pregnancy (55.5 percent). 

Whether the unplanned pregnancy represented a failure to delay or to terminate 

childbearing makes little difference in the 

decision to change methods. 

The conclusion of this analysis then is that 

the experience of an unplanned pregnancy does 

increase the probability of changing methods. 

The magnitude of that effect is perhaps less than 

one might expect (the difference between 38.4 

and 55.5 percent), but there is no question that 

it does operate. The “effect” seems simiIar in 

magnitude to that inferred from the change in 

intentions. 

11

SUMMARY 

Based on interview data collected in the 

1975 National Fertility Study, this report has 

attempted to estimate aggregate changes in contraceptive practice that have occurred in the 

United States among continuously married 

white couples (both spouses married once) since 

1973 and has included comparable data from 

1970 and 1965, Because the 1975 study included reintewiews with a subsample of the 

same women first interviewed in 1970, it was 

also possible to examine individual changes in 

methods and some of the factors influencing 

such changes. 

At the aggregate level, it appears that there 

has been a continued increase in the proportion 

of married couples currently using contraception 

and a continued decline in the proportion that 

have never used contraception. Although the pill 

remains the most popular method of birth control among white women married less than 10 

years, there is evidence of the possible beginnings of a decline among most longer marriage 

duration categories. 

The main challenge to the supremacy of the 

pill comes from the increasingly popular method 

of surgical sterilization, now clearly the most 

commonly used method among couples married 

10 years or more. Its rapid adoption in the Iast 

few years, especially of the female procedure 

which has become technologically simpler, suggests that sterilization of one kind or the other 

(including sterilizing surgery for medicaI reasons 

only) may now be the most common barrier to 

conception among married couples of reproductive age. There has been a considerable increase 

in reliance on this method over the past decade. 

Three-quarters of couples using contraception are using the most effective methods available: sterilization, the pill, or the IUD. AI1 of 

the trend data suggest a rapidly growing dependence on such methods by persons in all social 

strata. 

At the individual level, about half of the 

women reinterviewed were using a different 

method in 1975 than in 1970. Most change was 

to sterilization which has between two and three 

times the drawing power of its nearest competitor, the pill. Beyond these two methods, only 

the condom and the IUD show any appreciable 

appeal to those using other methods. Changes in 

methods are more likely to occur in the transition between the period during which contraception is used to delay conception and the 

period after desired family size is reached in 

which it is used to avoid further pregnancy; 

however, among those who have not already 

been sterilized, changes are almost equally likely 

after this transition is completed. 

Besides the motivational change from delaying to preventing future pregnancies, the experience of an unpkmned pregnancy also shows an 

effect on changes in methods, Those who reported an unplanned pregnancy during the 

1971-75 period were more likely to change 

methods than those who reported either no 

pregnancy or a planned pregnancy. It is cIear 

from the magnitude of these effects that factors 

other than fertility intentions and pregnancy 

experience influence the decision to change contraceptive methods. 

REFERENCES 

I Natio~~ c~nte~for He~th stati~ti~~: The National 

Survey of Family Growth Cycle I: Sample design, estimation procedures, and variance estimation. 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. 

2Ryder, N. B., and Westoff, C. F.: Reproduction in 

the United States: 1965. Princeton, N. J. Princeton University Press, 1971. 

3Westoff, C. F., and Ryder, N. B.: The Contraceptive 

Revolution. Princeton, N. J. Princeton University Press, 

1977. 

4National Center for Health Statistics: Contraceptive 

utilization among currently married women 15-44 years 

of age: United States, 1973, by K. Ford. Monthly Vital 

Statistics Report. Vol. 25, No. 7, Supp. DHEW Pub. No. 

(HRA) 76-1120. Health Resources Administration. 

Rockville, Md. Oct. 4, 1976. 

5Westoff, C. F., ~d Jones,E. F.:The sec~arization 

of U.S. Catholic birth control practices. F’am. Plann. 

Perspect. 9(5):203-207, Sept./Ott. 1977. 

12

LIST OF DETAILED TABLES 

1,	 Number and percent distribution of women by type of exposure to the risk of conception (standardized by the 1970 marriage duration distt, bution), according to whethar additional births wera intended: currently married white women 15.44 

years of age, both spouses married once, 1966, 1970, 1973, and 1975 ...................................................................................... 14 

2.	 Number and parcent distribution of women by type of exposure to risk of conception, according to duration of marriage: 

currently married whita women 15-44 years of age, both spouses married once, 1965, 1970, 1973, and 1975 ... ....................... 15 

3.	 Number and percent distribution of women by type of exposure to the risk of conception (standardized by the 1970 marriage duration distribution), according to wife’s education: currently married whita women 15-44 years of age, both spouses 

married once, 1965, 1970, 1973, and 1976 .............................................................................................................................. f7 

4.	 Percent of women who have never used contraception, by duration of marriage (standardized by the 1970 marriage duration 

distribution): currently married white women 1544 years of age, both spouses married once, 1965, 1970, 1973, and 1975 .... 17 

5.	 percent of women who have never used contraception, by duration of marriage and marriage cohort: currently married 

whita women 18-39 years of age, both spouses married once, 1955, 1960, 1965, 1970, and 1975 .......................................... . 18 

6.	 Percent of women using contraception who are using the most effactive methods (sterilization, pill, IUD), by duration of 

marriage (standardized by the 1970 marriage duration distribution): currently married white women 15-44 years of age, 

both spouses marriad once, 1965, 1970, 1973, and 1975 .......................................................................................................... 18 

7.	 percent of women using contraception who are using the most affective methods (sterilization, pill, IUD), by duration of 

marriage and marriage cohort: currantly married white women 1544 years of age, both spouses married onca, 1965, 1970, 

and 1975 ..................................................................... ........................................................................... ................................ .... 19 

8. Percent of women surgically sterilized or whose husbands were sterilized, by type of oparation and duration of marriage 

(standardized by the 1970 marriaga duration distribution): currently married white women 1544 years of age, both spouses 

married once, 1965, 1970, 1973, and 1975 .............................................................................................................................. 20 

9.	 Number and percent distribution of women by typa of exposure to the risk of conception in 1975, according to type of 

exposura in 1970: currantly married white women, both spouses married once, and married 5-24 years in 1975 ...................... 21 

10.	 Number and percent distribution of women by method of contraception used in 1975, according to method used in 1970: 

currently married white women, both spouses married once, and married 5-24 years by 1975 .................................................. 21 

11.	 Number and percent distribution of women by method of contraception used in 1975, according to whather additional 

children were intended in each yaar and mathod of contraception used in 1970: currently marriad whita women, both 

spouses married once, and married 5-24 years by 1976 ............................................................................................................. 22 

12.	 Number and percent distribution of women who changad methods of contraception during 1971-75 by prior method, 

according to method used in 1975: currently married white women, both spousesmarried once, 1975 .................................... 23 

13.	 Percent change of method in relation to pregnancy experience for the 1971-75 period: currently married white women 

married less than 25 years, both spouses married onca, 1975 ..................................................................................................... 23 

13 
Table 1. Number and percent distribution of women by type of exposure to the risk of conception (standardized by the 1970 marriage duration


distribution), according to whether additional births were intendad: currently married white women 15-44 years of aga,l both spousas


married onca, 1965, J970, 1973, and 1975


All women 1ntend more Intend no more 

Type of exposure 

1975 1973 1970 1965 1975 1973 1970 1965 1975 1973 1970 1965


Numbar 

All wom~rs ...................... 3,329 3,906 I 3,764 2,826 II 1,208 I 1,448 I 1,310 [ 982 2,120 I 2,458 2,474 I 1,644 

Percent distribution 

All types of exposure ...... 100.0 100.0 100.0 100.0 II 100.0 100.0 100.0 I 100.0 100.0 I 100.0 100.0 I 100.0 

Using contraception ........................ 79.0 72.9 67.6 66.5 64.9 64.7 59.7 59.2 85.6 77.8 77.7 71.6 

Not using contraception.~.: .............. 21.0 27.1 32.4 33.5 35.1 35.3 40.3 40.8 14.4 22.2 28.3 28.4 

Pregnantr postpartum, trying to 

get pregnant ................. ........... 12.0 13.1 15.0 16.4 27,9 28.1 30.5 31.1 4.5 4.5 8.8 7.5 

7.2 9.8 9.7 + 9.8 21.6 

I


Sterile and other nonusers ......... 9.0 + 14.0 17.5 + 17.1 7.2+F-17.7T20.9 

Number 

Ali ~men using


contraception .................... 2,617 I 2,S53 I 2,558 1,901 11 806 930 [ 763 I 581 1,811 I 1,923 1,775 I 1,320


All methods . ......................... 100.0 100.0 100.0 100.0 100.0 100.01 100.0 100.0 100.0 100.0 100.0 100.0 

Wife sterilized ................................. 16.3 10.8 6.8 4.7 . . . . . . . . . . . . 22.6 15.6 9.7 7.4 

Husband sterilized ........................... 15.0 11.2 7.2 4.1 . . . . . . . . . . . . 20.9 16.3 10.3 6.3 

Pill .............. .............. ...................... 34.3 35.5 35.4 28.4 59.5 58.2 51.2 43.2 24.1 25.5 28.5 22.0 

lUD . ........... ........... .......................... 8.7 9.5 7.5 1.1 11.6 12.1 1.3 7.7 8.4 7.3 1.1 

Diaphragm ...................................... 3.9 4.0 5.7 10.5 4.2 3.6 E 6.2 3.7 4.3 6.4 12.7 

Condom .......................................... 10.9 15.1 14.8 22.0 11.2 12.8 11.0 18.4 10.5 16.2 16.5 23.4 

Withdrawal . ..................................... 2.0 2.3 2.3 4.0 2.0 1.7 1.8 3.0 2.0 2.6 4.3 

Foam .... .......................................... 3.6 5.3 6.6 3.1 4.7 6.9 10.2 4.6 3.4 ::: 5.0 2.1 

Rhythm .......................................... 2.8 4.0 7.1 11.5 4.4 2.9 7.0 12.9 2.6 4.5 7.2 10.0 

Douche ...... ..................................... 0.4 0.5 2.3 3.4 0.3 0.2 2.3 2.9 0.4 0.7 2.3 3.6 

Other ............... .... ...... ..................... 2.2 1.7 4.3 7.1 2.1 1.6 4.2 7.3 2.3 1.7 4.3 7.7 

n-he pOP~atiOn of ~Omen represented in this table is further restricted to those married before age 25 and married leaa than 25 Yeara. 

14

Table 2. Number and	 parcent distribution of women by type of exposure to risk of conception, according toduration of marriage: currently


married white women 15-44 years of age,l both spouses married once, 1965, 1970,1973, and 1975


All durations Less than 5 yaars 5-9 years 

Type of exposura 

1975 1973 1970 1965 1975 1973 1970 1965 1975 1973 1970 1965


Number 

All woman ...................... 3,328 I 3,806 I 3,784 I 2,826 Ii 1,041 1 1,080 I 1.010 I 600 703 I 882 653 I 614


Percent distribution 

All types of exposure ...... 100.0 100.0 100.0 100.0 1] 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 _ 

Using contraception ................ ........ 78.6 70.5 65.7 84.9 71.3 68.9 61.7 58.5 76.7 75.0 69.2 69.7 

Not using contraception ......... ......... 21.4 29.1 34.3 35.2 28.7 31.1 36.3 41.5 23.3, 25.0 30.8 30.3 

+ 

Pragnant, postpartum, trying to 

get pragnant ............................ 12.8 14.2 15.0 14.7 23.2 25.0 29.6 34.5 17.4 18.5 19.7 19.4 

Starile and othar nonusars ......... 8.6 15.2 17.5 + 18.0 5.5 + 6.1 8.7 7.0 6.0 6.5 11.1 10.9 

Number 

All woman using 

contraception ................ .... 2,617, 2,853 , 2,556 , 1,901 II 742 748 I 623 351 I 539 I 661 I 590 [ 428 

Parcent distribution 

All mathods ............. ............. 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 

Wife stabilized ..................... ............ 16.6 11.6 6.8 5.3 0.8 1.9 0.3 0.0 11.7 9.4 3.9 2.1 

Husband sterilized ................. .......... 14.4 11.9 4.4 0.6 1.0 0.3 10.0 9.0 4.2 3.0 

Pill .................................................. 35.7 35.6 3;:: 25.8 6::; 64.1 57.1 53.3 36.6 39.4 42.9 34.6 

lUD ....... .......................................... 8.5 9.6 7.5 1.1 8.1 9.7 14.5 14.5 11.4 1.9 

Diaphragm ...................................... 3.9 4.0 5.7 11.0 4.3 2.6 3 E 3.3 3.2 4.2 10.3 

Condom .......................................... 10.9 14.9 14.8 22.7 12.0 11.4 9.8 14.8 11.7 10.3 13.6 22.0 

Withdrawal ...................................... 2.0 2.3 2.3 4.2 1.8 1.6 1.4 2.8 1.7 2.1 1.4 2.6 

Foam .... .... ...... ................................ 3.6 5.2 6.6 2.9 3.4 4.3 8.2 4.6 4.6 8.2 6.8 3.5 

Rhythm .......................................... 2.8 3.9 7.1 11.8 2.0 5.0 8.5 2.2 2.2 4.7 10.7 

Douche ........................................ ... 0.4 0.5 2.3 3.5 ::: 0.2 1.8 !3.7 0.2 0.4 1.0 1.2 

Other .............................................. 2.2 1.7 4.3 7.3 2.0 1.5 3.4 5.7 1.5 1.3 3.9 8.2 

lThe population of women represented in this table is further restricted to those married before age 25 and married less than 25 Years 

15

Table 2. Number and percent distribution of women by type of exposure to risk of conception, according to duration of marriage: currently


married whita women 1544 years of age,l both spouses married once, 1965, 1970, 1973, and 1975-Con.


10-14 years 15-19 years 20-24 years 

Typa of exposure 

1975 1973 1970 1965 1975 1973 1970 1965 1975 1973 1970 1965


Number 

All woman ...................... 632 I 731 I 731 I 571 I 553 I 710 I 626 I 636 I 400 I 493 I 564 I 405


Percent distribution 

All types of exposure ...... 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0I 100.0 100.0 

Using contraception ........................ 85.9 80.8 75.4 73.7 85.9 71.6 67.9 70.6 79.5 67.8 I 65.4 62.2 

Not using contraception ................<. 14.1 19.2 24.6 26.3 14.1 26.4 32.1 28.4 20.5 32.2 34.5 37.8 

Pregnant, postpartum, trying to 

get pregnant ................... ......... 6.2 8.0 8.5 7.4 2.9 3.0 4.5 5.5 15. 1.8 1.6 3.0 

Sterile and other nonusers ......... 7.9 11.2 16.1 18.9 11.2 25.4 27.6T23.9 19.1 t 30.4 33.0 34.8 

Number 

All women using


contraception .................... 543 594 I 551 421 475 513 I 425 I 449 318 I 337 369 252


Percent distribution 

All methods .......................... 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 _ _ _ 

Wife stabilized ................................. 20.6 15.3 7.4 7.1 27.8 13.3 13.4 9.1 30.2 18,8 13.6 8.3 

Husband sterilized ........................... 22.7 15.1 7.8 5.2 23.8 18.7 12.2 5.8 25.5 18.2 15.4 8.7 

Pill .................................................. 25.2 22.4 28.1 20.7 15.8 22.0 20.7 10.5 10.4 16.0 14.6 8.7 

lUD ................................................. 9.0 11.2 8.2 0.7 5.1 6.4 4.0 1.1 3.8 2.2 2.7 0.0 

Diaphragm ...................................... 1.7 3.9 6.4 10.5 4.0 5.7 8.2 13.8 7.5 6.1 8.1 17.1 

Condom .......................................... 8.8 17.1 16.0 25.9 9.5 19.2 19.1 25.8 12.6 21.6 18.4 23.8 

withdrawal ...................................... 3.3 4.5 3.4 3.9 2.8 5.1 2.5 3.3 3.5 6.3 

Foam .............................................. ::: E 6.7 3.6 2.9 2.2 4.2 1.3 1.9 3.7 3.0 0.8 

Rhythm .......................................... 3.5 4.6 8.2 13.5 4.0 6.2 9.2 12.9 3.1 6.6 10.6 13.5 

Douche ........................................... 0.4 0.5 3.3 0.6 1.0 3.1 4.7 0.6 0.8 5.1 5.2 

Other .............................................. 2.6 1.9 ::: 5.0 3.2 1.5 3.1 9.8 1.9 2.5 4.9 7.5 

lThe ~opula~on of women ~epre~ented in this table is further restricted to those married before age 25 and married less than 25 years. 

16

Table 3, Number and percent distribution of women by type of exposure to the risk of conception (standardized by the 1970 marriage duration


distribution), according to wife’s education: currently married white women 1544 years of age, I both spouses marriad once, 1965.1970.


1973, and 1975


Soma high school or lass Completed high school Some collage


Type of exposure


1975 1973 1970 1965 1975 1973 1970 1965 1975 1973 1970 1965


Number 

All women ....... ............... 439 847 I 784 850 I 1,606 I 2,028 I 1939 I 1,407 I 1,264 I 1,031 I 1,061 568 

Percant distribution 

All typas of exposure ...... 100.0 100.0 100.0 100.0[ 100.0 100.0 100.0 100.0 

Using contraception ........................ 75.7 68.0 59.2 76.6 71.5 72.7 

Not using contraception,., ........ .. ..... 24.3 34.0 40.8 32.8 I 21.6 23.4 28.5 27.3 

Pregnant, postpartum, trying to 3 

get pregnant ............................ 13.1 16.0 15.1 11.9 12.4 14.6 16.4 14.0 14.2 14.9 16.3 

Starlla and other nonusars ......... 1::: 20.9 24.8 23.9 I 8.2 13.6 16.7 16.4 I 7.6 9.2 13.6 11.0

Number 

All women using


contraception .................... 329 I 555 452 I 523 I 1,282 1 1,505 i 1,333 957 I 1,006 I 793 I 773. I 420


Percent distribution 

Diaphragm ...................................... 1.1 1.7 2.2 3.7 3.4 3.0 5.9 11.5 5.5 7.5 7.6 17.1 

Condom .......................................... 4.1 12.2 12.8 23.8 12.2 17.8 15.2 22.6 11.4 12.4 15.1 18.7 

Withdrawal ...................................... 3.3 3.6 3.5 8.8 2.4 2.6 2.3 4.0 1.1 0.8 1.8 0.6 

Foam .............................................. 2.1 4.1 5.6 3.2 4.4 5.2 6.8 2.6 3.0 6.2 6.7 4.2 

Rhythm .......................................... 1.5 3.6 4.6 7.8 3.2 4.0 8.0 14.2 2.8 4.2 7.1 10.4 

Douche........................................... 1.2 1.1 6.6 4.7 0.2 0.4 1.6 3.3 0.4 0.3 0.9 2.2 

All methods .......................... 100.0 100.0 100.0 100.0 100.0 1s)0.0 100.0 100.0 100.0 100.0 100.0 100.0 

Wifa stabilized ................................. 

Husband sterilized ........................... 

25.8 

15.2 

17.2 

12.8 

13.7 7.5 

4.9 

17.1 

14.7 

10.7 

10.9 u 4.2 3.8 

11.6 

14.8 

. 7.1 

11.0 

4.8 

7.6 

2.9 

4.1 

Pill .... ............. .. ............................... 35.9 32.9 3;:: 27.2 32.6 35.1 36.8 26.0 37.0 37.6 34.9 33.4 

7.7 8.1 6.6 0.9 7.9 8.7 7.1 0.9 10.0 11.8 8.8 1.5 

Other .............................................. 1.9 I2.5 4.6 9.6 2.1 1.8 4.1 7.0 2.5 1.1 4.5 4.7 

lThe population of women represented in this tatde is further restricted to those married before age 25 and married less than 25 Years. 

Table 4. Percent of women who have never used contraception, by duration of marriage (standardized by the 1970 marriage duration


distribution): currently married white women 1!5A4 years of age,1 both spouses married once, 1965, 1970, 1973, and 1975


I I I I


Marriage duration 1975 1973 1970 1965


I Percent 

All durations . .. .... .. .. .. ... ... .. .. .. .. .... .. .. .. .... .. .. .. .... .. ... .. .. ... ... .. .. ... .. ... .. ... .. ... .. .. ... . ... . .... .. .. .. . . ... . . ... . 

[ 

5.3 1 9.6 I 12.2 I 14.3 

Less than 5 years .. .. .... .. ... . .. .... ... . .. .... .. .. .. ... .. .. ... ... .. .. .. ... .. .. . ... .. ... .. ... .. ... .. .. .. ... ... .. ... . .... .. .. .. .. .... .. .. .. ......... 11.7 16.5 

5-9 years .... .. ... .. ... .. .. .. .. .... .. .. ... . .. .. .. ... ... .. .. .. .. ... .. ... ... .. .. .. .... . ... .. ... .. ... .. ... .. .. .. .. .... ... .. . .... .... .. ...... ............... 8.3 11.7 

10-14 years . .... .. .. ... ... .. .. ... .. ... .. .. .. ... ... .. .. .. .... .. .. .... . ... .. ... .. ... .. .. ... ... .. .. .. ... ... .. ... ... .. . ... .. .. .. .... .. ... . ..... ........... 10.0 10.9 

15-19 years .. .. .. ... ... . .. .. . .... ... ... . ... .. .... .. .. ... .... .. ... .. ... ... .. .. .. .. .. ... .. .. .. .. .. .. ... .. .. ... . ... ... ... . ... . .. ... .. .... . ............... 16.2 14.0 

20-24 years .. ... .. .. . ... .. ... ... .. . ... ... .. ... .. .. .. .. .. . ... .. .. .. .. .. .. .. .. .... .. .. . ... .. .. ... ... .. .. .. ... .. ... ... .. .. ... .. ... . ... . .................. 17.6 19.4 

lThe population of women represented in this table is further restricted 

d 

to those married before age 25 and married 

1-

leas than 25


years.


17

Table 5. Percent of women who have never used contraception, by duration of marriage and marriage cohort: currently married white 

women 18-39 years of age,l both spouses married once, 1955, 1960, 1965, 1970, and 1975 

Duration of marriage in years 

Marriage cohort Less 

than 5-9 10-14 15-19 20-24 

5 

Percant 

1971-75 . .. .... .. .. .... . .. ... .. .... . ... ... .. .. . .. .. .. .. ... .. ... .. .. .... .. ... .. .. ... .. ... .. .. .. .. ... .. ... .. ... .. .. .. ... .. .. .. .. .. ... ... .... 5.2 

1966.70 . .. ... .. ... ... .. .. ... . ..... .. .. .. .. ... ... .. .. .. .. .. .. .. .. ... .. ... . .... . .... . ... .. ... ... .. .. .. ... .. ... .. .. ... .. .. .. ... . ............ 9.6 2.1 

1961-65 ... ... .. .. ... .. ... .. ... ... .. .. .. .. .. .. . ... .. ... .. .. .... ... . .. ... .. .. ... ... ... .. .. .. ... .. ... .. ... .. .. .. .. ... .. ... .. .. .. ... .. . ...... 15.4 8.3 5.1 

1956.60 .. .... .. ... .. .. ... . ... .. ... ... .. .. .. ... .. ... .. .. .. ... ... .. .. ... ... ... . .... .. .. ... .. .. .. ... .. ... .. . .. .. .. ... .. .. .. .. .. .. ........... 23.7 11.7 10.0 5.2 

1951-55. . .... .. .. ... .. . ... ... .. ... .. ... .. ... . ... .. ... .. .. ... ... .. .. ... ... .. .. .... .. .. .. .. ... . .... .. .. ... .. ... . ... .. .. ... . ... .. ... . .. ..... 32.4 13.7 10.9 4.9 9.3 

1946.50 ..................................................................................................... O.................. CC
 ........ 21.5. 17.6 4.5 12.9

1941-45 .............................................................................................................................. .... 23.2 19.9 19.4


193640 .......................... .. ........................................................................................... O.......... 32.8 19.4


1931.35 .......................i .......................................................................................................... 40.6


lThe ~oPulation of women re~re~ented in thi~table is further restricted to those married before age 25 and married less than 25 

years. 

NOTE. –Percents on the diagonals refer to the women in each duration group atthetime ofeach survey. Figures inthe two bottom 

diagonals are from the 1955 and the 1960 Growth of American Family Studies; the next three diagonals in ascending order are, 

respectively, from the 1965, 1970, and 1975 National Fertility Studies. Data intherows therefore refer to the same marriage cohorts of 

women represented in the different samplesat successive durations of marriage. 

Table6. Percent of women using contraception who are using the most effective methods (stabilization, pill, lUD), by duration of 

marriage (standardized by the 1970 marriage duration distribution): currently married white women 1544 years of age,l both 

spouses married once, 1965, 1970, 1973, and 1975 

Marriage duration 1975 1973 1970 1965 

I 

Percent 

All durations .............................. ........ .................................................. ................................. 74.3 67.0 56.9 38.3 

Less than 5 yaars ... ... .. .. ... . ... . .... .. .. ... .. .. .. .. ... ... .. . .... . .. .. . . .... .. .. .. ... ... .. .. .... . ... .. .. .... ... ... .. .. .. .. .. .. ... ... ... .......... 74.4 76.3 66.9 55.0 

5-9 years .. .. . ... . .. . ... .. .. ... ... .. .. .. .. .. .. . ... . .... .. . .. . .. ... .. .. .. .... . .. ... . .. .. .. . .... .. .. .. .... .. . ... .. .. .. .... . ... ... . ... ...... ............... 74.8 72.3 62.4 41.6 

10-14 years .. ... .. .. .. ... .. ... ... . . .. .. . ... .. .. .. . ... .. . ... .. ... . ... ... .. .. .. ... .. .. ... .. .. . ..... . ... .. .. ... . ... .. ... .. .. ... .. .. ... .. .. ............... 77.5 64.0 51.5 33.7 

15-19 years .. ... . .. ... .. .. ... .... . .. .. .. .. .. .. ... .. ... .. .. ... . ... . .. .. .. .. .. .. .. . ... .. .. .. .. .... . . .... .. .. .. . .... .. ... . .... .. . ... .. ... ..... ........... 72.5 60.4 50.3 26.5 

20-24 years .. .. .. . ... .. .... . .. .... . ... .. ... ... ... .. . ... ... .. .. ... .. .. .. ... .. ... .. .. .. .. .. ... . ... . .... .. .. .. ... .. .. ... .. . ... ... . .. .. .. .. ............... 69.9 55.2 46.3 25.7 

lThe population of women represe~tedin this tableisfurther restricted to those married before age 2S and married less than 25 

years. 

18 
Table7. Percent of women using contraception who are using the most effective methods (sterilization, pill, lUD), by duration of 

marriage and marriage cohort: currently married white women 15-44 years of aga, 1 both spouses married onca, 1965, 1970, and 1975 

Marriage duration in years 

Marriage cohort 

E 

Percent 

1971.75 . .. ... . .... . ... ... .,,, . .. .. .. .... . ... .. ... .. .. .. . .. ... .. .. .. . ... ... ... .. .. . ... .. .. .... .. .. .. .. .. .. ... .. ... .. .. .. .. ... ... . ... ...... 74.4 

1966-70 ,,, ,,, ,.,, ,,, ,, ..., . ... ... . ... ... . ... .. .. .. .. ... . .. ... .. ... ... .. ... ... ... ... ... . .. .... . ... .. ... .. . .. . .. . .. .. .. ... .. ... .. .. .. .... . . 66.9 74.8 

1961.65 . .. ... .. .. ... ... . .... .. ... ... . ... .. .. .. ... .. . ... . .. .. ... ... ... ... ... .. .... . .. .. .. .. ... . ... .. .. ... .. ... . ... ... .. .. .. ... ............ 55.0 62.4 77.5 

1956.60 . . .... .. ... .. ... ... .. .. ... . .... .. .. .. .. ... . .. .. ... . ... ... .. ... ... .. .... ... ... .. .. .. ... .. .. .. ... .. .. ... .. ... . .... .. .. .. ............ 41.6 51.5 72.5 

1951.55 . .. ... .. ... ... .. .. ... ... .. .. ... .. . ... .. ... . ... .. .. .. .. ... .. ... ... ... .. .... ... .. .. ... . .. ... . ... ... .. .. ... .. ... ... . .. .... ........... 33.7 50.3 69.9 

1946.50 . .. ... ... .. .. ... ... ... .. ... . ... .. .. .. .. ... ... . .. .. ... .. .. .. .. .... .. .. .. .. ... ... .. .. ... ... .. .. .. ... . ... . ... .. .... .. ... .. ........... 26.5 46.3 

1941.45 . .. .... .. .. .. ... .. .... . ... .. ... .. .. . ... ... . .. .. .. .. ... .. ... .. ... .. .. ... ... ... .. ... . ... . ... .. .. ... . ... ... ... .. ... .. .... . ........... 25.7 

, 

lThe po~ulation of ~~men ~enresented inthi~ table is further restri~ted to those married before age 25 and married le~s than 25 

years. - -

NOTE.-The upper diagonal containa data from the 1975 survey ;the middle diagonal, 1970 data; andthe lower diagonal, 1965 data. 

19 
Table8. Percent of women surgically sterilized or whose husbands were sterilized, by typa of operation and duration of marriege 

(standardized by the 1970 marriage duration distribution): currently married white women 15-44 years of age,l both spouses 

married onca, 1965, 1970, 1973, and 1975 

Marriage duration 19751 1973 I 1970 I 1965 

Total sterilized 

All	 durations ......................................................................................................................... 

Standardized ................................................................................................................... 

Lessthan 5 years .................................................................................................................................. 

5-9 yaars ............................................................................................................................................... 

10-14 years ........................................................................................................................................... 

15-19 years ................................................................................................................................ ........... 

20-24 years .......................................................................................................................................... . 

Tubal ligation3 

All	 durations .............................................................................................................................. 

Standardized ......................................................................................................................... 

Lessthan 5 years .................................................................................................................................. 

5-9 years .......................................................................................................................................... ..... 

10-14 years ........................................................................................................................................... 

15-19 years ........................................................................................................................................ ... 

Hysterectomy 

All	 durations .............................................................................................................................. 

Standardized ......................................................................................................................... 

Lessthan 5 years .................................................................................................................................. 

5-9 years ............................................................................................................................................... 

10-14 years ................................................................................................................................ ........... 

15-19 years ........................................................................................................................................... 

20-24 years ........................................................................................................................................... 

Vasectomy 

All	 durations .............................................................................................................................. 

Standardized ......................................................................................................................... 

Lessthan 5 years .................................................................................................................................. 

5-9 yaars ............................................................................................................................................... 

10-14 years ........................................................................................................................................... 

15-19 years ........................................................................................................................................... 

20-24 yean ........................................................................................................................................... 

Percent 

26.4 21.2 14.3 13.1 

28.1 21.7 14.3 11.9 

1.3 2.1 1.0 0.7 

17.0 14.9 6.4 5.0 

40.1 29.0 15.0 16.1 

50.2 34.1 27.1 20.9 

53.1 44.3 34.4 27.2 

9.7 7.2 4.0 3.4 

10.2 7.4 4.0 3.0 

0.6 1.5 0.3 0.0 

7.9 7.3 2.2 1.8 

16.1 10.9 5.4 5.4 

17.5 9.0 7.5 5.7 

15.5 12.0 7.6 4.2 

4.9 5.7 4.0 5.7 

5.4 5.8 4.0 5.2 

0.1 0.1 0,1 0.3 

1.1 0.6 0.7 0.7 

4.4 5.4 2.5 6.1 

11.0 10.4 8.4 9.3 

16.5 19.3 13.1 15.1 

11.c 8.1 4.9 3.1 

11.~ 8.3 4.9 2.9 

O.e 0.4 0.6 0.3 

7.5 7.0 3.0 2.1 

19.0 12.6 5.6 3,9 

19.5 13.7 8.4 4.4 

19,5 12.7 10.3 5.9 

lThe population of women represented inthistable is further restricted to those married before age 25 and married less than 25 

years. 

21ncludes other typea of operations, multiple operations, and operations Of tYpe unknown. 

3For 1975 incIudes laparoscopy, aprocedme not developed andin useat the time of the=dkrstdk 

20 
Tabla9. Number and percent distribution of women by typo of expmure totherisk ofconceptionin 1975, according totvpeof exposure in 1970 currently married white women,1 

both spousesmarried once, and married 5-24 wars i“ 1975 

Type of exposure, 1975 

Number 

Not using 

contracepti.m Using contraception 

TYPS of exposure, 197o of 

women Total Pregnant, Sterile 

postpartum, and wife Husband Pill IUD Diaphragm Condom Foam Rhythm Other trying to get other sterilized sterilized 

pregnant nonusers 

Percem distribution 

All categories................. 2,348 100.0 7.9 10.1 17.6 — 

16.2 19.5 7.0 3.1 8.8 3.0 2.6 3.9

Not mi”g contraception: 

Pregnant, postpartum, trying 

to get pregnant ...................... 412 100.0 14.6 10.2 13.6 13.6 20.1 8.7 1.2 9.0 4.1 3.2 1.7 

Sterile and other nonusers,, ...... + 270 100.0 9.3 40.0 12.6 9.6 9.6 4.1 2.2 4.4 0.4 3.0 4.8 

Wing contraception: 

I 

Wife sterilized .......................... 126 100.0 . . . . . . 99.2 . . . 0.8 . . . . . . . . . . . . . 

Husband sterlllzed, ................... 101 100.0 1.0 . . . . . . 99.0 . . . . . . . . . . . . . . . . . . . . . 

Pill ........................................... 609 100.0 6.o 5.3 13.1 14.3 41.5 5.7 1.6 5.1 2.3 1.5 1.5 

lad ...................................... 136 100.0 3.7 2.2 22.1 10.3 10.3 43.4 2.2 2.2 2.9 0.7 

Diaphragm ............................... 97 100.0 9.3 8.2 12.4 13.4 4.1 4.1 36.1 6.2 1.0 2.1 3.1 

Condom ................................... 234 100.0 6.0 7.3 11.1 14.5 10.3 1.7 1.3 40.6 1.7 0.9 4.8 

Foam ....................................... 121 100.0 9!1 6.6 18.2 14.9 19.0 4.1 1.7 2.5 19.0 4.9 

Rhythm ................................... 111 100.0 4.5 7.2 10.8 12.6 9.9 6.3 3.6 14.4 20.7 9.9 

Other ....................................... 131 100.0 4.6 6.4 16.8 13.7 15.3 3.1 3.1 3.1 4.6 3.1 24.4 

lThe population of women represented in this table is further restricted to those married before age 25. 

Table IO. Number andparcent dlstributionof women by method of contraception used in1975, according tomethod used in1970: currently married 

white womenrlbot"h spousesmarried one&, andmarried 5-24 years by 1975 

Number Method of contraception used in 1975 

in 1970 women Total Wife Husband Pill IUD Diaphragm sterilized sterilized 

Condom Foam Rhythm Other 

Percent distribution 

All methods ................... 1,479 100.0 22,2 20.1 23.7 8.0 4.1 10.7 3.5 2.8 4.9 

Wife sterilized ................................ 126 100.0 99.2 . . . 0.8 . . . . . .,. . . . .,. . . . 

Husband sterilized ......................... 100 100.0 . . . 100.0 . . . . . . . . . . . . . . . . . . . . 

Pill ................................................. 528 100.0 15.2 16.5 47,9 6.6 1.9 5,9 2.7 1.7 1.7 

lUD ............................................... 126 100.0 23.4 10.9 10.9 46.1 2.3 2.3 3.1 0.8 

Diaphragm, .................................... 80 100.0 15.0 16.3 5.0 5.0 43.8 7.5 1.3 2.5 3.8 

Condom ........................................ 203 100.0 12.8 16.7 11.8 2.0 1,5 46.8 2.0 1.0 5.5 

Foam, ............................................ 102 100.0 21.6 17.6 22.5 4.9 2.0 2.9 22.5 5.9 

Rhythm.,.., .................................... 98 100.0 12.2 14.3 11.2 7.7 4.1 16.3 23.5 11.2 

Other .........i ................................... 114 100.0 19,3 15.8 17.5 3.5 3.5 3.5 5.3 3.5 28.1 

lThe population of women represented in this table is further restricted to those married before age 25. 

Method of contraception used of 

21 
Table Il. Numbarand percant distribution ofwomen bymethod ofcontraception used in1975, according totiether additional children were intanded 

in each yearand method ofcontraception usedin 1970:currently marridwhite women,lboth spousasmarried once, andmarried 5-24 years by 1975 

Vumber Method of contraception used in 1975 

Intention status and method of of contraception usedin 1970 women Total Wife Husband Pill IUD Diaphragm Condom Foam Rhythm Other 

sterilized sterilized 

Pill ................................................. 71 100.0 . . . . . . 56.3 16.92.6 6.6 

All other ........................................ 45 100.0 . . . . . . 28.9 20.0 6.7 13.3 11.1 11.1 8.9 

Intanded more in 1970 and 

no more in 1976 

Intended	 more in 1970 and 

in 1975 Percent distribution 

All methods ................... 116 100.0 . . . . . .	 45,7 18.1 4.3 9,5 9.5 6.0 6.9 

= 

2.6 7.0 8.5 

All methods ................... 334 100.0 15.0 13.2 35.3 11.4 4.5 10.6 4.8 0.6 4.5 — 

Hll ................................................. 154 100.0 13.6 13.6 50.6 8.4 6.5 2.6 2.6


lUD ............................................... 32 100.0 21.9 12.5 18.8 40.6 ::: 3.1


Diaphragm 6.3 

Condom ........................................ 40 100.0 10.0 7.5 20.0 5.0 5.0 45.0 2.5 5.0 

Foam ............................................. 39 100.0 23.1 10.3 25.6 7.7 5.1 23.1 5.1 

Rhythm ......................................... 27 100.0 14.8 18.5 18.5 18.5 3.7 14.8 7.4 

Other ............................................. 26 100.0 15.4 7.7 34.6 3.8 7.7 3,6 3.8 2::; 

Intended no mora in 1970 

andin 1975 

..................................... 16 100.0 6.3 31.3 12.5 137.5 6.3 0.0


All methods ................... 1,025 100.0 27.2 24.8 17.1 5.8 4.0 10.8 2.4 3.1 4.8 

Wife sterilized ...............................! 126 100.0 99.2 . . . 0.8 . . . . . . . . . . . . . . . . . . 

Husband sterilized ......................... 100 100.0 . . . 100.0 . . . . . . . . . . . . . . . . . . . . . 

Pill ................................................. 300 1Oost 19.7 22.0 44.0 3.3 1.7 5.3 1.3 2.3 0.3 

IUD ............................................... 87 100.0 26.4 11.5 6.9 !8.3 2.3 3.4 1.1 

Diaphragm ..................................... 62 100.0 17.7 12.9 3.2 45.2 8.1 1.6 3.2 4.0 

Condom ........................................ 156 I 00.0 14.1 19.9 8.3 ::; 0.6 47.4 1.9 1.3 6.8 

Foam ............................................. 55 100.0 23.6 25.5 14.5 1.8 1.8 1.6 23.6 0.0 7.3 

Rhythm ......................................... 59 100.0 13.6 15.3 6.5 5.1 15.3 27.1 15.3 

Other ............................................. 80 I 00.0 22.5 20.0 10.0 3.8 1.3 3.8 5.0 5.0 26.8 

I’fhe population of women *ePre~e~ted in this table is further restricted to those married before age 25. 

22 
Table 12. Number and percent distribution Of women who changed methods of contraception during 1971-75 by prior method, 

according to method used in 1975: currently married white women, 1 both spouses married once, 1975 

Method of contraception used in 1975 

Prior method of contraception Wife Husband 

sterilized sterilized 

Pill IUD Diaphragm Condom Foam Rhythm 

Number 

All women ............................... .... . 249 232 I 320 152 I 73 I 182 I 95 [ 50 

Percent distribut~on 

100.0 100.0 I 100.0 100.0 I 100.0 I 100.01100.0 I 100.0 

Other 

Pill . .. .. .. .. .. ... ... . ... .. .. ... .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. ... 40.2 45.7 55.3 52.1 57.1 75.8 58.0 

lUD . .. .. ... . .... .. .. .. .. .... . ... .. ... .. .. .. ... .. .. . ... . ... .. .. .. .. 12.4 6.0 14:; 9.6 8.8 10.5 4.0 

Diaphragm .. .. .. ... .. ... .. .. ... .. .. ... . ... . ... .. .. .. .. .. .. .. .. 6.8 6.5 7.8 5:9 2.2 1.1 8.0 

Condom .. .. .. .. .. .. .. .. .. ... .. .. .. ... .. .. .. .. .. .. .. .. .. .. .. .. .. 14.1 21.1 35.0 15.1 26:0 . . . 10.5 14.0 

Foam . .. .. .... .. ... .. ... . ... .. .. ... .. .. .. ... .. .. . ... . ... . .. ... .. . 10.0 11.6 24.4 12.5 6.8 92.6 6.0 

Rhythm . . .. ... .. ... . ... .. .. .. .. . . .... .. .. .. .. .. .. .. ...i . ... .. .. 6.8 3.0 7.5 3.9 1.4 8.2 ;:1” . . . 

............................................................ 9.6 L6.0 10.6 7.3 4.1 10.9 0.0 10.0 

lTh~ ~oPulation of women represented in this table is further restricted to those married before age 25 and married less than 25 

years. 

Table 13. Percent change of method in relation to pregnancy experience for the 1971-75 period: currently married white women 

marriedl less than 25 years, both spouses married once, 1975 

Pregnancy planning status in period Number Number of Total Changed No change 

of women pregnancies method in method 

I I I Percent distribution 

No pregnancy 2 .. .. .. .. .. .. ... .. ... .. .. .. .. .. .. ... ... .. .. .. .. .. .. .. .. .. .... .. .. .. .. .. .. . ... .. ... .. ... .. 1,893 100.0 37.2 62.8 

Plenned pregnancy3 .. .. ... ... .. ... . .. .. .. .. ... ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .... .. .. .. ... . .. .. .. 473 531” 100.0 38.4 61.6 

Unplanned pregnancy4 ..... .. .. .. .. ... ... .. .. ... ... .. .. ... .. ... .. ... . ... ... .. .. .. .... . .... . ... .. .. 371 427 100.0 55.5 44.5 

Timing failure5 ... ... . .... .. .. .. .. .. .. .. .. ... .. .. ... .. .. ... ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 222 254 100.0 54.7 45.3 

Number failure6 ... .. .... . ... ... .. .. .. .. .... .. .. .. .. ... ... .. .. .. ... .. ... .. .. .. .... . ... ... .. .. .. . 160 173 100.0 56.6 43.4 

lThe population of ~omen represented in this table is further restricted to those married before age 25 and married less ‘ban 25 

years. Women married less than 30 months are also omitted. 

2percent bused on number of ~omen; ~n]y periods of continuous contraceptive use of at least 3&months duration are considered. 

3~ercent based on nUrnber of pregnancies; planned pregnancies where contraception was used before the Pregnancy and resumed 

within no more than 4 months after the pregnancy are included. 

4percents based on number of pre~ancies; unplanned pregnancies where contraception wx used within 6 months before the 

pre mmcy and resumed within no more than 4 months after the pregnancy are included. 

%Timing tkilure means birth wanted but at a Mer time. 6Number failure means birth not ~nted at a]l. 

*	 US, GOVSRNMSNS’PRIN’IMG OFFICE :1979 0-2S1-259 (17) 

23 
VITAL AND HEALTH STATISTICS Series 

Series 1.	 programs and collection Procedures. –Reports which describe the genera] programs of the National 

Center for Heafth Statistics and its offices and divisions and data collection methods used and include 

definitions and other material necessary for understanding the data. 

Series 2.	 Data Evaluation and Methods Research. –Studies of new statistical methodology including experimental tests of new survey methods, studies of vital statistics collection methods, new analytical 

techniques, objective evaluations of reliability of collected data, and contributions to statistical theory. 

Series 3.	 Analytical Studies. –Reports presenting analytical or interpretive studies based on vital and heaIth 

statistics, carrying the analysis further than the expository types of reports in the other series. 

Series 4.	 Documents and Committee Reports. –Final reports of major committees concerned with vital and 

heafth statistics and documents such as recommended model vital registration laws and revised birth 

and death certificates. 

Series 10.	 Data From the Health Interview Survey. –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. 

.$erics 11.	 Data From the Health Examination Survey and the Health and Nutrition Examination Survey .–Data 

from direct examination, testing, and measurement of national samples of the civilian noninstitutionalized population provide the basis for two types of reports: (1) estimates of the medically defined 

prevalence of specific diseases in the United States and the distributions of the population with respect 

to physical, physiological, and psychological ch~acteristics and (2) analysis of relationships among the 

various measurements without reference to an explicit finite universe of persons. 

Series 12.	 Data From the Institutionalized Population Survey s.–Discontinued effective 1975. Future reports from 

these surveys will be in Series 13. 

Series 13.	 Data on Health Resources Utilization. –Statistics on the utilization of health manpower and facilities 

providing long-term care, ambulatory care, hospital care, and family planning services. 

Series 14.	 Data on Health Resources: Manpower and Facilities. –Statistics on the numbers, geographic distribution, and characteristics of health resources including physicians, dentists, nurses, other health 

occupations, hospitals, nursing homes, and outpatient facilities. 

Series 20.	 Data on Mortality. –Various statistics on mortality other than as included in regular annual or monthly 

reports. Special analyses by cause of death, age, ~d other demographic variables; geographic and time 

series analyses; and statistics on characteristics of deaths not available from the vital records based on 

sample surveys of those records. 

Series 21.	 Data on Natality, Marriage, and Divorce. –Various statistics on nat~ity, marriage, and divorce other 

than as included in regular annual or monthly reports. Special analyses by demographic variables; 

geographic and time series analyses; studies of fertility; and statistics on characteristics of births not 

available from the vital records based on sample surveys of those records. 

Series 22.	 Data From the National Mortality and Natality Surveys. –Discontinued effective 1975. Future reports 

from these sample surveys based on vital records will be included in Series 20 and 21, respectively. 

Sen’es 23.	 Data From the National Survey of Family Growth. –Statistics on fertility, family formation and dissohrtion, family planning, and related maternal and infant health topics derived from a biennial survey 

of a nationwide probability sample of ever-married women 15-44 years of age. 

For a list of titles of reports published in these series, write to: Scientific and Technical Information Branch 

National Center for Health Statistics 

Public Health Service 

Hyattsville, Md. 20782 .