From Vital and Health Statistics of the National Center for Health Statistics Number 104 � February 11, 1985 

Fecundity and Infertility in the United States, 1965-82 

by William D. Mosher, Ph. D., and William F. Pratt, Ph. D., Division of Vital Statistics 

In 1982, about half of all American married couples with 

wives in the childbearing ages were currently sterile or had 

some childbearing impairment. Almost 8 million of these couples 

were voluntarily sterilized because they had had all the children 

they wanted. However, another approximately 6 million couples 

were unable or unlikely to have additional births, including 

about 1.4 million couples who were childless. These and related 

statistics on fecundity and infertility in the United States are 

from the National Survey of Family Growth, most recently 

conducted in 1982 by the National Center for Health Statistics. 

This report presents, for the first time, preliminary nationwide statistics on the fecundity status of all women of repr~ 

ductive age in the United States, regardless of marital status, 

and reports the latest data on trends in fecundity and infertility 

among married couples. The data on currently married women 

in this report update statistics published in a previous report. 1 

The data for 1976 and 1982 were collected in Cycles II and III 

of the National Surveys of Family Growth (NSFG’S); the data 

for 1965 are from the 1965 National Fertili~ Study conducted 

by Princeton University.2 

The 1982 NSFG was based on personal interviews with a 

national sample of 7,969 women in the childbearing ages 

(15-44 years of age) in the noninstitutionalized population of 

the conterminous United States. Between August 1982 and 

February 1983 interviews were conducted with 3,201 black 

women and 4,768 women of races other than black. The interview focused on the respondent’s fecundity (or physical ability 

to have children); past and current use of contraception; marital 

and pregnancy history; use of family planning and infertility 

services; labor force participation; and a wide range of social, 

economic, and demographic characteristics. 

The Concept of Fecundity Status 

The respondent’s physical ability to have children was 

measured by her answers to a series of questions, not by a 

medical examination. The purpose of this series of questions 

was to classify couples into three major groups: surgically sterile 

(impossible to have a baby); impaired fecundity (nonsurgically 

sterile or difiicult or dangerous to have a baby); and fecund (no 

known physical problem). The questions included the following 

As far as you know, is it possibIe or impossible for you . . . 

to get pregnant (again)? 

As far as you know, is there any problem or difilculty for 

you . . . to conceive or deliver a(notber) baby? 

In these questions, the words “as far as you know” are 

important. Many women who have never tried to become pregnant do not know whether they have a fecundity impairment. 

Some women who reported that they did not know of any 

physical problems nonetheless have had long periods of time in 

which they did not conceive although they used no contracep 

tion. A few women maybe classified as having fecundity problems because of underreporting of either contraceptive use or 

pregnancies, but there is no evidence that this underreporting 

has a significant effect on the estimates presented here? Finally, 

while some women with fecundity problems subsequently may 

have children, their reduced capacity for childbearing has an 

impact on the nation’s birthrate and on the estimates of couples 

needing medical services to improve their chances of childbearing. 

The category “surgically sterile” is divided into two sub 

groups: contraceptively and noncontraceptively sterile. The 

category “contraceptively sterile” consists of women or their 

current husbands who have had a sterilizing operation (tubal 

ligation, hysterectomy, or vasectomy) at least partly because 

they had had all the children they wanted. Table 1 shows that 

in 1982, 17 percent of all women 15–44 years of age were 

contraceptively sterile, including 1 percent of never married 

women, 28 percent of currently married women (or their husbands), and 20 percent of formerly married women. Not surprisingly, in each marital status category the percent contraceptively sterile was much higher for women with children 

(parity 1 or more) than for childless women (parity O). 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service 
2 

Table 1. Number of women 15–44 years of age end percent distribution by fecundity status, according to marital status, perity, and sge: 

United States, 1982 

[Prel,minav statistics based on a sample of the female population of the conterminous United States. See Technical notes for est,mates of sampling variability and 

definitions of terms] 

Surgically sterile Impaired fecundity 

NonMarital status, parity, All All surgically Long 

and age women Total Contraceptive Noncontraceptive impaired sterile Sub fecund interval Fecund 

MARITAL STATUS Number in 

AND PARITY thousands Percent distribution 

All women, . . . . . . . . . . . 54,099 100.0 17.4 7.8 8.2 1.6 5.4 1,2 00.0 r--

Parity O ., . . . . . . . . . . . . 22,941 100,0 1.4 1.7 8.4 2.5 5.2 0.7 88.5 

Parity l or more, ..,.., 31,158 100.0 29.2 12.4 8.1 1.0 5.6 1.5 50.2 

Never married 

Allparitiee . . . . . . . . . . . . 19,162 100.0 1.3 “0.8 4,1 1.0 3.0 0.1 93.8 

Parity O..,....,...,,. 16,693 100.0 “0.3 “0.4 3.7 1.0 2.6 0.1 95.6 

Parity l or more....,.. 2,469 100.0 7.9 *3.8 *6.4 0.8 5.6 0.0 81.8 

Currently married 

All parities, . . ...,,.... 28,231 100.0 27.8 11,0 10.5 2.0 6.3 2.1 50.7 

Parity O . . . . . . . . . . . . . . 5,098 100,0 *4.6 *5.3 21,7 7.2 11,8 2,6 68.4 

Parity l or more, . . . . . . 23,134 100,0 33.0 12.3 8.0 0.9 5.1 2,0 46.7 

Formerly married 

All parities...,,....,,. 6,706 100.0 19.9 14.4 10.7 1.9 8.7 0.0 54.9 

Parity O . . . . . . . . . . . . . . 1,150 100.0 *4.2 *4. 1 *16.6 2.1 14.3 0.1 75.1 

Parity l or more ..,,... 5,556 100.0 23.2 16,6 *9.4 1.8 7.6 0.0 50.8 

AGE 

15-19 years . ...,...., 9,521 100,0 0.0 ‘2.1 “0.5 *1.6 97.9 

20–24 years . . . . . . . . . . 10,629 100,0 3.7 “0.6 6.0 “0.9 4,9 “0.2 89.7 

25-29 years, .,....... 10,263 100.0 12.1 3.7 10.3 *1.5 7,7 “1.0 73.9 

30-34 years . . . . . . . . . . 9,381 100.0 26.7 10.1 9.2 *1.7 6.5 *1.1 54.0 

35-39 years . . . . . . . . . . 7,893 100.0 35.3 18.4 12.6 3.1 7.0 *2.5 33.7 

40-44 years . . . . . . . . . . 6,412 100.0 39.4 21.8 10,8 *2.9 4.7 *3.2 28.0 

Women classified as “surgically sterile for noncontracep 

tive reasons” had sterilizing operations for reasons other than 

limiting the size of their families. Table 1 shows that 8 percent 

(about 4.2 million) had had such operations, including 1 percent of never married women, 11 percent of currently married 

women (or their current husbands), and 14 percent of formerly 

married women. The percent sterilized for noncontraceptive 

reasons also was higher for women with children than for childless women. 

Women classified as “nonsurgically sterile” said that it 

was impossible to have a baby for some reason other than a 

sterilizing operation—such as accident, illness, or unexplained 

inability to conceive. As of 1982, 0.9 million women (2 percent) were classified as nonsurgically sterile. The percent 

nonsurgically sterile was 1 to 2 percent in each marital status 

category. 

Women classified as “subfecund” said that it was physically 

diflicult for them to conceive or deliver a baby, or that a doctor 

had told them never to become pregnant again, because of danger 

to the woman, the baby, or both. In 1982, 5 percent, or about 

2.9 million women, were classified as subfecund, including 

3 percent of never married, 6 percent of currently married, and 

9 percent of formerly married women (table 1). 

Women or couples who were continuously married (either 

formally or informally), did not use contraception, and did not 

become pregnant for 36 months or more were classified as 

having a “long interval.” Although these women reported no 

known physical problems, they were well beyond any normal 

period for conception, indicating some impairment to childbearing and possibly sterility. As of 1982, 1 percent of all 

women, or about 0.6 million women, had a long interval. 

The category “impaired fecundity” includes women who 

were classified as nonsurgically sterile, subfecund, or having a 

“long interval” since their last pregnancy. About 4.4 million 

women, or 8 percent, had impaired fecundity. Of these, about 

1.9 million were childless and about 2.5 million had 1 or more 

children (calculated from table 1). 

“Fecund” is a residual category consisting of women who 

were not surgically sterile (and whose husbands were not surgically sterile) and did not have impaired fecundity. In table 1, 

94 percent of never married women were classified as fecund, 

compared with about 51 percent of currently married and 

55 percent of formerly married women. There are two main 

reasons for this large difference between never married and 

ever married women. never married women are younger on 

average than ever married women, and most never married 

women have never been pregnant or tried to become pregnant. 

As a result, never married women are much less likely to be 
admceMa3 

surgically sterile than ever married women, and have had less 

chance to develop or discover any fecundity problems. 

Table 1 also contains data for all women by age. Differences between age groups also reflect differences in marital 

status, parity, and other factors. The percent contraceptively 

sterile increased with age, from 4 percent at ages 20–24 to 

39 percent at ages 40-44. The percent noncontraceptively 

sterile also increased with age, especially after age 30. The 

percent with impaired fecundity ranged from 2 percent at ages 

15– 19 to 13 percent at ages 35–39. Because both surgical 

sterility and impaired fecundity are more common at the older 

ages, the percent fecund declined from 98 among teenagers to 

28 among women 40–44 years of age. 

Trends Among Married Couples: 

1976 to 1982 

In 1982, as in 1976, the proportions of couples in both 

categories of surgical sterilization increased with age and both 

were greater among couples with children than among childless 

couples (table 2). However, the proportions contraceptively 

sterile differ sharply by parity at each age while noncontracep 

tive sterilization is little affected by parity. In both years, impaired fecundity was notably more common among childless 

women. It also increased with age, especially among childless 

couples: about half the childless couples 35–44 years of age 

had impaired fecundity. The increase in impaired fecundity 

with age was not statistically significant among couples with 

children in 1982. 

The percent of married couples who were contraceptively 

sterile increased by half—from 19 percent in 1976 to 28 percent in 1982—as shown in table 2. The largest increase occurred among couples with wives 35–44 years of age who had 

1 or more children. Changes in the percents surgically sterile 

for noncontraceptive reasons were not marked and generally 

were not statistically significant. The proportion of currently 

married couples who were surgically sterilized (all reasons) 

rose at a faster rate from 1976 to 1982 than from 1965 to 1976 

(table 3): an increase of 10.7 percentage points from 1976 to 

1982 (1.8 percentage points per year) compared with an increase of 12.4 percentage points from 1965 to 1976 (1.1 percentage points per year). 

Overall and among those with children, between 1976 and 

1982 the proportions of couples with impaired fecundity decreased, although at 15–24 years of age the decline was not 

statistically significant. There was no significant change in any 

of the three age groups in the proportion of childless couples 

with impaired fecundity (table 2). 

The proportion fecund decreased from 56 to 51 percent 

overall, primarily because of the decline from 35 to 26 percent 

among wives 35–44 years of age with children (table 2). The 

overall decline in the proportion of childless couples who were 

fecund (from 73 to 68 percent) was entirely due to the older 

age composition of childless couples in 1982 compared with 

1976; there were no significant declines in the percent fecund 

in any age group of childless couples. 

InfertilityAmong Married Couples 

“Infertility” is a medical concept for identi~ing couples 

potentially in need of medical services to improve their chances 

of childbearing. When neither partner is surgically sterile, a 

Tabla 2. Number of currently married women 15-44 years of aga and percent distribution by facundity stetus, according to parity and age: 

Unitad Statas, 1976 and 1982 

[Statistics are based on samples of the female population of the conterminous lJnotedStates. See Technical mtes for estimates of sampllng variability and definitions 

of terms. Data for 1982 are prelimina~] 

Parity and age 

All parities 

15-44 years . . . . . . . . . . . . . . . . . . 

15-24 years . . . . . . . . . . . . . . . . ,.. 

25-34 yesrs ...,,...,.,,....,.. 

35–44 years . . . . . . . . . . . . . . . . . . 

Parity O 

15–44 years . . . . . . . . . . . . . . . . . . 

15-24 years . . . . . . . . . . . . . . . . . . 

25-34 years . . . . . . . . . . . . . . . . . . . 

35-44 years . . . . . . . . . . . . . . . . . . 

Parity 1 or more 

15-44 years . . . . . . . . . . . . . . . . 

15-24 years, . . . . . . . . . . . . . . . . . 

25-34 years, . . . . . . . . . . . . . . . . . . 

35-44 years, . . . . . . . . . . . . . . . . . 

All women 

1982 1976 

Number in 

thousands 

28,231 27,488 

4,741 6,020 

12,924 12,179 

10,566 9,288 

5,098 5,235 

1,989 2,738 

2,256 1,931 

853 565 

23,133 22,253 

2,752 3,282 

10,668 10,248 

9,713 8,723 

Surgically sterile 

Non contra- Impaired 

Total Contraceptive ceptive fecundity Fecund 

1982 1976 1982 1976 1982 1976 1982 1976 1982 1976 

Percent distribution 

100.0 100.0 27.8 la,5 11,0 9.6 10.5 5.7 50.7 56.1 

100.0 100.0 *6.6 3.5 “0.6 “0.4 *8.O 0.8 84.8 85.3 

100.0 100.0 23,8 19,1 7.7 6.8 9.4 5.5 59.0 58.7 

100.0 100.0 42,3 27,6 19.8 19.4 12.8 9.1 25.1 33.9 

100.0 00.0 *4.6 1.5 *5.3 4.1 21.7 21,4 68.4 73.0 

100.0 00.0 - “0,2 “0.1 - *11,1 10.6 88,8 89.3 

100.0 00.0 *6.2 *1,8 *3,5 4.5 21.1 27.3 69.2 66.4 

100.0 00.0 *1O,8 *6.5 *22.5 22,3 47.8 53.9 *18.9 17.2 

100.0 100.0 33,0 22.6 12.3 11.0 8.0 14.3 46.7 52.2 

100.0 100.0 *11.3 6.2 ‘1.0 “0.8 *5.8 11.1 81.9 62.0 

100.0 100.0 27.6 22.3 8.6 7.2 7.0 13,2 56.8 57.3 

100,0 100.0 45.0 29.0 19.6 19.2 9.7 16.8 25.7 34,9 
4 aduancedata 

Table 3. Number of currently married women 15-44 years of age and percent distribution by infertility status, according to age, parity, and 

race: United States, 1965, 1976, and 1982 

[Statistics are based on samplea of the female population of the conterminous United States. See Technical notes for estimates of sampling variability and definitiona 

of terms. Data for 1982 are prelimina~] 

Age, parity, and race 

Total . . . . . . . . . . . . . . . . . . 

AGE 

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

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

25-29 years . . . . . . . . . . . . . 

30-34 years . . . . . . . . . . . . . 

35–39 years . . . . . . . . . . . . . 

40-44 years . . . . . . . . . . . . . 

PARITY 

o	 . . . . . . . . . . . . . . . . . . . 

1 .... ......... ..... 

2	 . . . . . . . . . . . . . . . . 

3 or more . . . . . . . . . . . . . . . 

RACE AND AGE 

White 

15–44 years . . . . . . . . . . . . . 

15–29 years . . . . . . . . . . . . . 

30-44 years . . . . . . . . . . . . . 

81ack 

15-44 years . . . . . . . . . . . . . 

15-29 years . . . . . . . . . . . . . 

30-44 years . . . . . . . . . . . . . 

All women 

1982 1976 19651 Total 

Number in thousands 

28,231 27,488 26,454 100.0 

612 1,043 1,032 100.0 

4,130 48977 4,397 100.0 

6,442 6,443 4,953 100.0 

6,482 5,736 5,074 100.0 

5,783 4,814 100.0 

4.783 4.474 } 10,998 100.0 

5,098 5,235 3,492 100.0 

5,891 5,571 4,497 100.0 

9,042 7,638 6,878 100.0 

8,201 9,045 11,587 100.0 

25,175 24,795 23,427 100.0 

10,005 11,217 9,166 100.0 

15,170 13,577 14,261 100.0 

2,125 2,169 43,027 100.0 

859 993 41,216 100.0 

1,266 1,177 41,811 100.0 

Infertility status 

Surgically sterile Infertile Fecund2 

1982 1976 1965 1982 1976 1965 1982 1976 1965 

Percent distribution 

38.9 28.2 15.8 8.4 10.3 11.2 52.7 61.6 73.0 

‘0.3 81.0 “0.6 “2.1 *2.1 “0.6 97.7 96.6 98.9 

*8.2 4.5 3.1 9.7 6.4 *3.5 82.1 89.2 93.4 

19.6 16.6 9.5 7.0 9.0 6.5 73.4 74.4 84.0 

43.6 36.2 17.0 7.7 10.3 11.6 48.7 53.5 71.3 

58.2 45.3 22.8 10.2 12.5 14.2 31.6 42.2 63.0 

66.7 49.0 26.8 9.0 15.9 20.2 24.3 35.2 52.9 

9.9 5.6 7.3 19.6 18.1 14.5 70.5 76.3 78.2 

17.7 8.8 7.5 10.6 12.4 17.2 77.7 78.8 75.3 

46.8 32.3 14.2 5.0 6.0 9.3 48,2 61.7 76.6 

63.4 49.8 21.5 3.8 7.9 9.4 32.8 42.3 69.0 

38.9 29.0 15.9 8.1 9.4 10.5 53.0 61.6 73.6 

13.7 10.7 5.5 7.4 6.7 4.4 78.8 82.6 90.1 

55.5 44.1 22.3 8.6 11.6 14.3 35.9 44.3 63.3 

36.3 21.6 14.2 13.1 18.1 16.3 50.6 60.3 69.5 

19.7 9.2 6.6 10.9 12,1 4.5 69.4 78.7 88.9 

47.5 32,1 20.6 14.6 23.2 26.1 37.9 44.7 53.3 

1For method of estimation, see Technical notes. 

‘The definition of “fecund” used in this table is different from the definition used in tables 1 and 2. 

31ncludes white, black, and other races, 

4Figurea are for racas other than white. 

couple is classified as infertile if, during the preceding 12 

months or longer, they were continuously married (presumed 

to be sexually active), had not used contraception, and had not 

conceived.4-6 The measure of infertility generally provides 

lower estimates than impaired fecundity, as in tables 1 and 2, 

because it includes only wives who have difIicuky conceiving, 

and excludes wives who are using contraception because a pregnancy would threaten their health. An important advantage of 

this measure is that we can measure the trend in infertility since 

1965 ,l,s as shown in tables 3 and 4. Not shown in the tables is 

the duration of infertility, which averaged (median) 27 months 

in 1982, with 47 percent of infertile couples having been infertile for 30 months or more. 

Changes in the percent infertile between 1976 and 1982 

generally were not statistically significant, except for the decline 

among women 40–44 years of age. However, during the longer 

period between 1965 and 1982, the proportion infertile showed 

a statistically significant decline, from 11 percent in 1965 to 

8 percent in 1982. This overall decline occurred because the 

increase in infertility among women under age 30 was more 

than offset by the sharp decline in the percent infertile among 

women 30–44 years of age. 

The decline in infertility among older women and overall 

is the result of the large increase in surgical sterilizations. 

Although it is possible that more women who know they are 

infertile may have surgical sterilizations, it seems more likely 

that the increasing use of contraceptive sterilizations reduces 

the proportions of women who otherwise would fmd themselves 

infertile at age .30 and older. 

When couples who were surgically sterile are excluded, 

the percent infertile did not change significantly between 1965 

(13 percent) and 1982 (14 percent) (table 4). Among couples 

who were not surgically sterile, for those with wives aged 

20–24 years, the percent infertile increased from 4 percent in 

1965 to 11 percent in 1982. This was the only statistically 

significant change in any age or parity group in table 4. 

Table 3 also contains data by race. The percent classified 

as infertile was higher among black than white couples in all 

three survey years; in 1982, 13 percent of black and 8 percent 

of white couples were classified as infertile. The increase in the 
dance&a5 

Table 4. Percent of currently married women 15-44 years of age (excluding surgically sterile) who were infertile by age, parity, and race: 

United States, 1966, 1976, and 1982 

[Statistics are based on samples of the female population of the conterminous United States. See Technical notes for estimates of sampling variability and definitions 

of terms. Data for 1982 are preliminary] 

Age, parity, and race 1982 1976 7965 

Total! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Age 

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

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

25-29 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

30-34 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

35-39 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

40-44 years . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Parity 

o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

3 or more . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Race 

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

black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Percent 

13.8 14.3 13,3 

*2.1 *2.1 *0.6 

10.6 6.7 *3.6 

8.7 10.8 7.2 

13.6 16.1 14.0 24.4 22.8 18.4 

27.2 31.1 27.7 

21.8 19.2 15.6 

12.9 13.6 18.6 

9.3 8.9 10.8 

*1 0.4 15.8 12.0 

13.3 13.3 12.5 

20.6 23.1 19.0 

1 Includes black, white, and other races. 

percent infertile, from 4 to 7 percent among white couples with 

wives 15–29 from 1965 to 1982, was not statistically signitlcant. There was a significant decrease, from 14 to 9 percen< 

among white couples with wives 30–44. The percent infertile 

among black couples 15-44 did not change significantly beReferences 

lNational Center for Health Statistics, W. Mosher and W. Pratt 

Reproductive impairments among married couples United States. 

Vital and Health Statistics. Series 23, No. 11. DHHS Pub No. (PHS) 

83-1987. Public Health Service. Washington. U.S. Government 

Printing Office, Dec. 1982. 

2N. B. Ryder and C. F. WestofE Reproduction in the United States, 

1965. Princeton, N.J. Princeton University Press, 1971. 

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at ages 15–29 years (5 to 11 percent) and a significant decrease at ages 30–44 years (26 to 15 percent). The changes 

between 1976 and 1982 for white and black women 15–29 

years of age were not statistically significant. 

5R Kleimnan and P. Senanayakex Handbook on Infertility. London. 

International Planned Parenthood Federation, 1979. 

I$R Ansbacher, M. Shapiro, C. L. Witten, and H. Bsrben Fomrn 

Management of infertility. The Female Patient 4(8~26-30, 1979. 

7U.S. Bureau of the Census: Marital status and family status March 

1965. Current Population Reports. Series P–20, No. 144, tables 1 

and 3. Washington. U.S. Government Printing Oftice, Nov, 1965. 

3W. Moshec Infertility trends among U.S. couplex 1965-1976. ‘U.S. Bureau of the Census Fertility of the population June 1964 

Family Planning Perspectives 14(1):22-27, Jan./Feb. 1982. and March 1962. Current Population Reports. Series P–20, No. 147, 

4R Hatcher, G. K. Stewart, F. Stewar& et al.: Contraceptive Tech- table 1. Washington. U.S. Government Printing OftIce, Jan. 1966. 

noiogy 1982-1983, 1Ith cd., p. 214. New York. Irvington Inc., 1982. 
6 akmdata 

Technical notes 

Survey design 

The National Survey of Family Growth (NSFG) is a 

periodic survey conducted by the National Center for Health 

Statistics to collect data on fertility, family planning, and related 

aspects of maternal and child health. Fieldwork for Cycles II 

and III was conducted under contract by Westat, Inc., in 1976 

and 1982, respectively. 

Personal interviews were conducted with a multistage area 

probability sample of women 15–44 years of age in the noninstitutionalized population of the conterminous United States. 

In Cycle II, conducted in 1976, ever married women and never 

married women with offspring living in the household were eligible for the survey. In Cycle III, all women aged 15–44 were 

eligible regardless of marital status or the presence of offspring. 

Women living in group quarters were excluded from the sample 

in Cycle II but included in Cycle III. Interviews were conducted 

with 8,611 women in Cycle II and 7,969 in Cycle III. Further 

details of the sample design of Cycle II are given in the report 

cited in reference 1. 

Fieldwork for Cycle III was conducted between August 

1982 and February 1983. Black women and women aged 

15–1 9 were oversampled. Interviews were conducted by trained 

female interviewers and lasted an average of 1 hour. The interview focused on the woman’s pregnancy history; use of contraceptives in each pregnancy interval; ability to bear children 

in the future; use of family planning and infertility services; 

marital history; labor force participatio~ and a wide range of 

social, economic, and demographic characteristics. 

Reliability of estimates 

Because the statistics presented in this report are based on 

a sample, they may differ from the statistics thatwould result if 

all 54 million women represented by the NSFG had been interviewed. The standard error of an estimate is a measure of such 

differences. The standard error of an estimated number or percent is calculated by using the appropriate values of A and B 

from table I in the equations, 

and 

B“P’”(lOO -P’) 112 

SE(F) = [ x’ 1

where N’ = the number of women 

P’ = the percent 

X’ =	 the number of women in the denominator of the 

percent 

NOTE: A list of references follows the text. 

Table 1. Parameters used to compute estimated standard errors 

and relative standard errors of numbers and percents of women, 

by marital status and race: National Survey of Family Growth 

Parameter 

Cycle, marital status, and race A B 

CYCLE Ill (1982) 

Ever married women 

Allraces and white . . . . . . . . . . . . -0.001097329 39,809.1677 

Black . . . . . . . . . . . . . . . . . . . . . . . -0.000908632 6,346.0484 

All marital statuses 

Allraces and white . . . . . . . . . . . . -0.0003935957 21,306.4134 

Black . . . . . . . . . . . . . . . . . . . . . . . -0.000908632 6,346.0484 

CYCLE II (1976) 

Currently married women 

All races . . . . . . . . . . . . . . . . . . . . . -0.000185899 6,751.0619 

White and other races. . . . -0.000205624 7,021.1665 

Black . . . . . . . . . . . . . . . . . . . . . . . -0.000631040 2,798.6440 

The chances are about 68 out of 100 that a sample estimate 

would fall within one standard error of a statistic based on a 

complete count of the population represented by the NSFG. 

The chances are about 95 in 100 that a sample estimate would 

fall within two standard errors of the complete count estimated. 

Differences between percents discussed in this report were 

found to be statistically significant at the 95-percent contldence 

level using a 2-tailed t-test with 39 degrees of freedom. This 

means that in repeated samples of the same type and size, a 

difference as large as the one observed would occur in only 

5 percent of samples, if there were, in fact, no difference between the percents in the population. 

The relative standard error of a statistic is the ratio of the 

standard error to the statistic and usually is expressed as a 

percent of the estimate. In this report, statistics with relative 

standard errors of 30 percent or larger are indicated with an 

asterisk (*). These estimates may be viewed as unreliable by 

themselves, but they may be combined with other estimates to 

make comparisons of greater precision. 

Statistics in this report also maybe subject to nonsarnpling 

error, that is, errors or omissions in responding to the interview, recording answers, and processing data. The data have 

been adjusted for nonresponse by means of adjustments to the 

sample weights assigned to each case. Other types of nonsampling error were minimized by a series of quality control 

measures as described in reports on Cycle II. 1 

The 1965 National Fertility Study 

The figures on infertility for 1965 in tables 3 and 4 were 

computed from the 1965 National Fertility Study and were 

published previously. ‘.3 The survey design and procedures are 

described in references 1 and 2. 

Unlike the NSFG, the 1965 National Fertility Study did 

not include procedures to obtain weighted numbers; therefore, 
adwncedata 7 

approximate numbers of currently married women for 1965 

were obtained from population estimates made by the U.S. 

Bureau of the Census. The weighted numbers shown for 1965 

in table 3 differ from those shown for 1976 and 1982 in the 

following ways: in the 1965 figures, Alaska and Hawaii are 

included, “black” includes women of all races other than white 

and the age range includes currently married women 14 years 

of age. The population estimates for 1965 are obtained from 

two reports published by the U.S. Bureau of the Census.T$ 

Definitions of terms 

Fecundity status—Fecundity is the physical ability of a 

woman or couple to have children at the time of interview, and 

refers to women with any number of children, unless classified 

by parity. It is determined by responses to questions asked in 

the NSFG interview, not by a medical examination. Fecundity 

status, as shown in tables 1 and 2, has three main categories: 

surgically sterile, impaired fecundity, and fecund. Women 

were classii3ed as surgically sterile if they (or their current 

husband) had had a sterilizing operation. Surgically sterile is 

divided into two subcategories: contraceptive and noncontraceptive. Impaired fecundity is divided into the subcategories 

nonsurgically sterile, subfecund, and long interval. Women 

were classified as nonsurgically sterile if they reported that it 

was impossible for them to have a baby for any reason other 

than a sterilizing operatio~ as subfecund if it was diflicult or 

dangerous to have a bab~ and as “long interval” if they had 

been continuously married (formally or informally), had not 

used contraception, and had not become pregnant for 3 or more 

years. In tables 1 and 2, fecund is a residual category and means 

that the woman (or couple) is not surgically sterile and does not 

have impaired fecundity. The percent of currently married 

couples with impaired fecundity is higher than the percent inNOTE: A list of references followsthe text. 

fertile because impaired fecundity includes difficulty in conceiving and difficulty or danger carrying to term, whereas infertility includes only difficulty in conceiving. For more detailed 

discussion of the concept of fecundity status, see the text of this 

report, and the report cited in reference 1. 

Infertili@ status-Infertility is a medical concep~ it identifies couples that may need medical services to improve their 

chances of having children. When neither spouse is surgically 

sterile, a couple is considered infertile if, during the previous 

12 months or longer, they were continuously married, had not 

used contraception, and had not conceived. Infertility status, as 

shown in tables 3 and 4, refers to the categories surgically sterile, 

infertile, and fecund, where fecund means neither surgically 

sterile nor infertile. 

Age—Age is classified by the age of the respondent at her 

last birthday before the date of interview. 

~ace—~ace refers to the race of the woman interviewed 

and is reported as black, white, or other. In Cycle III, race was 

classii3ed according to the woman’s report of the race that best 

described her. In Cycle II, race was classified by the observation of the interviewer. Cycle III data indicated that results 

using either method of classiilcation were very similar. 

Marital status—Persons were classified by marital status 

as married, widowed, divorced, separated, or never married. In 

Cycle II, informally married women—women who volunteered 

that they were sharing living quarters with their sexual partner— 

were classified as currently married. These women constituted 

about 3 percent of currently married women in Cycle II. To 

improve the comparability of NSFG results overtime and with 

other sources of data, in Cycle III such women were classfled 

according to their legal marital status. In both cycles, women 

who were married but separated from their spouse were classified as separated if the reason for the separation was marital 

discord, and as currently married otherwise. 

Panly—Parity refers to the number of live births the 

woman has had. 

Symbols 

. . . Data not available 

. . . Catego~ not applicable 

0.0 

z 

* 

Quantity zero 

Quantity more than zero but less than 

0.05 

Quantity more than zero but less than 

500 where numbers are rounded to 

thousands 

Figure does not meet standard of 

reliability or precision (30 percent or 

more relative standard error) 
8 aduancedata 

Recent Issues of Advance Data From Vital and Health Statistics 

No. 103. Use of Services for Family Planning 

States, 1982 (Issued Dec. 20, 1984) 

No. 102. Use of Contraception in the United 

Dec. 4, 1984) 

No. 101. 1983 Summary: National Hospital 

sued Sept. 28, 1984) 

Suggested Citation -

and Infertility: United 

States: 1982 (Issued 

Discharge Survey (IsNo. 100. CAT Scan Use in Short-Stay Non-Federal Hospitals: 

United States, 1979-82 (Issued Sept. 28, 1984) 

No. 99. Health Care of Adolescents by Office-Based Physicians: 

National Ambulatory Medical Care Survey, 1980–8 1 (Issued Sept. 

28, 1984) 

Copyright Information 

This report may be reprinted without further 

permission. 

THIRD CLASS MAIL 

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PERMIT No. G-281 r 

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National Center for Health Statistics, W. D. Mosher 

and W. F. Pratt: Fecundity and infertility in the 

United States, 1965-82. Advance Data From Vital 

and Hea/th Statistics. No. 104, DH HS Pub. No. 

(PHS) 85–1 250. Public Health Service. Hyattsville, 

Md., February 11, 1985. 

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