National Health Statistics Reports
 

Number 113  July 11, 2018 

Fertility of Men and Women Aged 15–44 in the 

United States: National Survey of Family Growth, 

2011–2015 

by Gladys M. Martinez, Ph.D., Kimberly Daniels, Ph.D., and Isaedmarie Febo-Vazquez, M.S. 

Abstract 

Objective—This report presents national estimates of selected fertility measures 

for men and women aged 15–44 in the United States in 2011–2015 based on data 

from the National Survey of Family Growth (NSFG). Estimates for 2011–2015 are 

compared with those for 2006–2010. 

Methods—Data were collected through in-person interviews of a nationally 

representative sample of the household population aged 15–44 in the United States 

from September 2011 through September 2015. The 2011–2015 NSFG sample 

comprised 20,621 respondents aged 15–44, including 9,321 men and 11,300 women. 

The response rate for the 2011–2015 NSFG was 72.3% for women and 69.6% for 

men. Fertility measures in this report include: have ever had a biological child, number 

of children born alive, timing of the first child, and birth spacing. 

Results—Most estimates of fertility measures for men and women aged 15–44 

in 2011–2015 were similar to those reported in 2006–2010. For 2011–2015, 85.0% 

of women had given birth and 80.4% of men had fathered a child by ages 40–44. On 

average, women had 1.2 biological children and men had fathered 0.9 children. The 

mean age at first birth was 23.1 for women and 25.5 for men. Among women, 31.2% 

of first births occurred during the teen years and 54.5% occurred during ages 20–29. 

Among men, 13.8% of first births occurred during the teen years and 63.1% occurred 

during ages 20–29. In 2011–2015, nearly one-third of women aged 15–44 with a birth 

had only had one birth at the time of interview, about one-third had a second birth 

within 36 months, and one-third had a second birth more than 36 months after their 

first birth. Estimates of fertility measures differed by age, marital or cohabiting status, 

education, household income relative to the federal poverty level, and Hispanic origin 

and race. 

Keywords: parity • number of children • age at first birth • birth spacing 

Introduction 

This report presents national 

estimates of selected fertility measures 

for both men and women in the United 

States during 2011–2015. In 2015, vital 

statistics data indicated there were 4 

million births in the United States; the 

number of births declined steadily during 

2007–2013, increased slightly in 2014, 

and decreased again in 2015 (1). The 

birth rate (number of births per 1,000 

females in a specific age group) declined 

for teenagers aged 15–19 and those aged 

20–24. The rate increased for women 

aged 30–39 and 40–44 (1). The mean 

number of children born declined, from 

three children per woman in 1976 to two 

children per woman in 2012 (2). 

Fertility research in the United 

States has focused on various topics, 

including characteristics of those who 

have children (3,4), how many children 

they have (2,3,5), timing of childbearing 

(e.g., adolescent childbearing, late 

childbearing) (2,6,7), and spacing of 

births (8). Having a child at an early 

age, particularly in the teen years, has 

been associated with negative social, 

economic, and health consequences for 

the young woman and her child (9–13), 

and it is estimated that in 2015 alone, the 

United States saved about $4 billion as 

a result of efforts to prevent unintended 

births among teenagers (14). On the other 

hand, later childbearing is associated with 

declines in U.S. total fertility rates (15). 

In 1970, the birth rate among women 

aged 20–24 was 168 births per 1,000 

women compared with 76.8 births per 

1,000 women in 2015 (1,16). The gap in 

the birth rate has narrowed for women in 

their 20s compared with women in their 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
 

Centers for Disease Control and Prevention
 

National Center for Health Statistics
 
Page 2	 National Health Statistics Reports  Number 113  July 11, 2018 

30s, and most recently, there has been a 

higher rate of childbearing among women 

in their 30s than women in their 20s. 

For example, in 2016, the birth rate for 

women aged 20–24 reached a record low 

at 73.8 births per 1,000 women, while 

the birth rate for women aged 30–34 was 

at the highest rate since 1964 at 102.7 

births per 1,000 women (17). In addition, 

spacing of births can have a significant 

impact on the health of the baby and the 

mother. Short birth spacing, defined as 

having a pregnancy less than 18 months 

after a previous birth, has been associated 

with adverse outcomes, including preterm 

delivery, low birth weight, congenital 

disorders, and poor health for the mother, 

including folate depletion and incomplete 

recovery from the prior birth, especially 

for cesarean deliveries (8,18–22). 

This report presents data on the 

fertility experience of men and women 

aged 15–44 in the United States using 

4 years of National Survey of Family 

Growth (NSFG) data collected during 

2011–2015, and it updates previously 

published estimates using 2006–2010 

data (3). Selected fertility measures 

include: have ever had a biological child, 

number of children born alive, timing 

of the first child, and birth spacing (for 

women only). The fertility measures are 

described by several key demographic 

characteristics, including age, marital or 

cohabiting status, education, household 

income relative to the federal poverty 

level, and Hispanic origin and race. 

Methods 

Data source 

This report is based on pooled 

NSFG public-use data for 2011–2013 

and 2013–2015. The combined 4 years of 

data collected in 2011–2015 come from 

20,621 face-to-face interviews—11,300 

with women and 9,321 with men— 

representative of the U.S. household 

population aged 15–44. The National 

Center for Health Statistics (NCHS) 

has been conducting NSFG since 

1973 to collect data on fertility and the 

proximate determinants (23) that explain 

fertility in the United States. NSFG is 

jointly planned and funded by NCHS 

and several other U.S. Department of 

Health and Human Services programs 

(see Acknowledgments). The response 

rate for the 2011–2015 NSFG was 

72.3% for women and 69.6% for men 

aged 15–44. More details on the sample 

design, fieldwork procedures, and 

variance estimation for the 2011–2013 

and 2013–2015 NSFG were previously 

published (24). 

Fertility measures 

This report focuses on fertility 

measures based on questions 

administered by an interviewer to 

respondents. Data are shown for both 

men and women, which is an important 

contribution, because there are limited 

sources of information on the fertility of 

men. The results presented in this report 

are described separately for men and 

women, because the fertility patterns of 

men and women differ across the life 

course. The average age at first birth 

is younger for women compared with 

men, so comparisons between men and 

women in the same age group would 

show differences solely for this reason 

(3). Although some results are presented 

that indicate whether the patterns of 

differences are similar for men and 

women, a systematic comparison of the 

fertility of men and women is not the 

focus of this report. 

The four fertility measures covered 

include: 

●	 Ever had a biological child 

○		 The percentage of women who 

have had a biological child 

○		 The percentage of men who have 

fathered a child 

●	 Number of children born alive 

○		 The percent distribution of the 

number of children born alive to 

women 

○		 The percent distribution of the 

number of children fathered by 

men 

●	 Timing of first birth 

○		 The percent distribution of age at 

first birth for men and women 

○		 The probability of a first birth 

by selected ages for men and 

women 

●	 Birth spacing (for women with at 

least one child) 

○ Number of months from first 

birth to second births (or 

percentage with no second birth 

at the time of interview) 

Selected demographic 

variables 

The fertility measures presented 

in this report are shown with respect to 

several key demographic characteristics, 

including age, marital or cohabiting 

status, educational attainment, household 

income relative to the federal poverty 

level, and Hispanic origin and race. With 

the exception of age and marital status at 

first birth in Table 6, all variables reflect 

the respondent’s own status at the time 

of interview. Educational attainment is 

shown only for respondents aged 22–44 

because many of those aged 15–21 are 

still attending school. Household income 

relative to the federal poverty level, 

shown as the respondent’s household 

income as a percentage of the federal 

poverty level accounting for the number 

of household members, is shown for 

respondents aged 20–44 because of 

concerns about younger respondents’ 

ability to accurately report on their 

household incomes. The definition of 

Hispanic origin and race used in this 

report takes into account the reporting 

of more than one race, in accordance 

with the 1997 guidelines from the Office 

of Management and Budget (25), and 

while not shown separately, data from 

respondents reporting more than one 

race are included in the total. Hispanic 

respondents, regardless of their racial 

identification, are shown separately and 

further categorized by their nativity 

status. 

Statistical analysis 

All estimates in this report are 

weighted to represent the approximately 

61 million men and 61 million women 

aged 15–44 in the household population 

of the United States. SAS software, 

Version 9.4 (www.sas.com), was used to 

produce statistics for this report. For most 

tables, PROC SURVEYFREQ was used 

to produce weighted percentages and 

variances that account for the complex 

sampling design of NSFG. Tables 1–6 

and the Appendix Table include standard 
National Health Statistics Reports  Number 113  July 11, 2018	 Page 3 

errors as a measure of the precision of 

each point estimate. 

In addition, PROC LIFETEST 

was used for Table 5 to calculate 

probabilities of a first birth using life 

table methodology. These probabilities 

represent the expected proportion of 

individuals who have had a first birth 

by a certain age, assuming the current 

age-specific first birth rates apply 

to future birth cohorts. Probabilities 

were estimated based on retrospective 

reporting of the age at first birth and are 

shown for those aged 18, 20, 25, 30, 35, 

and 40. In this report, probabilities are 

described as percentages, such as the 

percentage of women who would have 

a first birth by age 18. Table 5 illustrates 

information beyond the distribution of 

age at first birth (Table 4) by showing the 

cumulative probability of having a first 

birth by specific ages. 

Overall, differences in fertility 

measures by demographic characteristics 

were evaluated using survey-adjusted 

Wald chi-square tests. Significance of 

differences between any two estimates 

was determined by standard two-tailed 

t tests at the 0.05 level using point 

estimates and their standard errors. 

A weighted least-squares regression 

method was used to test for linear trends 

across age, education, and household 

income. Terms such as “increased” and 

“decreased” or “higher” and “lower” 

indicate there was a statistically 

significant difference between the two 

estimates. When statistics compared did 

not demonstrate a statistically significant 

difference, terms such as “similar” or “no 

difference” were used. 

In this report, data presentation 

standards for proportions are based on a 

minimum denominator sample size and 

on the absolute and relative widths of 

a confidence interval calculated using 

the Korn–Graubard approach (modified 

Clopper–Pearson) for complex surveys. 

All estimates presented meet the NCHS 

guidelines for presentation of proportions 

(26). When a percentage or other statistic 

is not shown for this reason, the table 

contains an asterisk signifying that the 

“statistic does not meet standards of 

reliability or precision.” This report 

also compares selected measures of 

the fertility of men and women in the 

United States during 2006–2010 and 

2011–2015. Statements describing an 

increase or decrease between two time 

points do not necessarily indicate a 

linear trend. The results presented in 

this report are descriptive and do not 

attempt to demonstrate cause-and-effect 

relationships. Differing age distributions 

may explain some of the differences 

shown in fertility measures across 

education, marital status, household 

income relative to the federal poverty 

level, and Hispanic origin and race. For 

example, non-Hispanic white women 

have fewer children, on average, 

which may in part be explained by age 

if Hispanic and non-Hispanic black 

women have a younger age distribution 

than non-Hispanic white women, 

and non-Hispanic white women have 

children at older ages. Differences in 

other characteristics, such as household 

income relative to the federal poverty 

level across marital status, may also 

account for some of the differences seen 

in fertility measures by marital status. A 

full multivariate analysis of these fertility 

outcomes that controls for differences 

across groups or standardizes across 

groups by other characteristics, such as 

age or household income relative to the 

federal poverty level, is beyond the scope 

of this report. 

Results 

Ever had a biological child 

Table 1 shows the percentage of 

men and women who had ever had a 

biological child by selected demographic 

characteristics. In 2011–2015, 54.9% of 

women and 43.8% of men aged 15–44 

had ever had a child, which was similar 

to their respective percentages in 

2006–2010. 

●	 In 2011–2015, 17.1% of women 

aged 15–24 and 85.0% of those aged 

40–44 had ever had a biological 

child. Among men, 7.6% of those 

aged 15–24 and 80.4% of those aged 

40–44 had ever had a child. 

●	 Among currently married women, 

80.4% had ever had a child, which 

is higher than the percentage for 

currently cohabiting women (59.4%). 

●	 Among both men and women, 

the percentage who had ever had 

a biological child was higher for 

individuals with lower levels of 

education. For example, 80.7% of 

women with a high school diploma 

or GED had ever had a child 

compared with 53.8% of women 

with a bachelor’s degree or higher. 

●	 Looking at household income 

relative to the federal poverty level, 

a higher percentage of women with 

household incomes below 150% 

of the federal poverty level had 

ever had a biological child (75.0%) 

compared with women whose 

household incomes were 300% or 

more than the federal poverty level 

(54.0%). A similar pattern was 

observed among men. 

●	 Among Hispanic men and women, 

looking at differences by nativity, 

a higher percentage of those born 

outside of the United States had ever 

had a biological child (63.7% of men 

and 79.3% of women) compared 

with those born in the United 

States (38.4% of men and 50.4% of 

women). 

●	 A higher percentage of Hispanic 

women, regardless of nativity, had 

ever had a biological child (62.1%) 

compared with non-Hispanic 

white (53.0%), non-Hispanic 

black (57.1%), and non-Hispanic 

Asian (48.9%) women (Figure 1). 

The percentage of Hispanic men, 

regardless of nativity, who had ever 

had a child (49.8%) was higher than 

non-Hispanic white (42.3%) and 

non-Hispanic Asian (35.6%) men 

but similar to the percentage for 

non-Hispanic black men (46.6%). 

The percentages were similar for 

non-Hispanic black (46.6%) and 

non-Hispanic white (42.3%) men. 

Number of children ever born 

Table 2 shows the percent 

distribution and mean number of children 

born to women aged 15–44 by selected 

demographic characteristics. The mean 

number of children decreased, from 1.3 

children in 2006–2010 to 1.2 children in 

2011–2015. There were no significant 

differences in the distribution of the 

number of children born in 2006–2010 

and 2011–2015. In 2011–2015, 45.1% of 

women had not had a biological child, 
Page 4	 National Health Statistics Reports  Number 113  July 11, 2018 

 

 

 

 

 

 

 

 

NOTES: The definition of Hispanic origin and race takes into account the reporting of more than one race, in accordance 

with the 1997 guidelines from the Office of Management and Budget. The “other race/multiple race reported” residual 

category is not shown separately but is included in the total. Chi-square statistics for “ever had a biological child by 

Hispanic origin and race” were statistically significant (p < 0.05). 

SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 

Figure 1. Percentage of women and men aged 15–44 who ever had a biological child, by 

Hispanic origin and race: United States, 2011–2015 

17.1% had one child, 19.7% had two 

children, 11.9% had three children, and 

6.2% had four or more children at the 

time of interview. 

●	 In 2011–2015, the majority of 

women aged 15–24 had not had a 

biological child (82.9%), and 15.0% 

of women aged 40–44 had not had a 

child. 

●	 The highest mean number of children 

ever born was reported by formerly 

married women (2.1), followed by 

currently married (1.8) and currently 

cohabiting (1.2) women. Formerly 

married women were more likely to 

have four or more children (13.9%) 

compared with currently married 

(8.4%) and currently cohabiting 

(7.2%) women. 

● Women with no high school diploma 

or GED had a higher average 

number of children (2.6) compared 

with women with higher levels of 

education (1.0–1.9) (Figure 2). In 

 

 

 

 

 

 

 

 

 

 

 

 

 

Percent 

●	 Women aged 20–44 living in 

households with incomes of 300% 

of the federal poverty level or higher 

at the time of interview were more 

likely to have not had a birth (46.0%) 

compared with women living in 

households in lower income groups 

(25.0%–36.4%). 

●	 When comparing differences by 

nativity, a higher percentage of 

U.S.-born Hispanic women had 

not had a child (49.6%) compared 

with Hispanic women born outside 

of the United States (20.7%). 

A lower percentage of Hispanic 

women (37.9%) had not had a 

child compared with non-Hispanic 

white (47.0%), non-Hispanic black 

(42.9%), and non-Hispanic Asian 

(51.1%) women. 

Table 3 shows the percent 

distribution and mean number of children 

fathered by men aged 15–44 by selected 

demographic characteristics. The mean 

number of children fathered by men in 

2011–2015 (0.9) was unchanged from 

2006–2010. In 2011–2015, 56.2% of 

men had not fathered a biological child, 

15.6% had fathered one biological child, 

16.2% had fathered two children, 8.1% 

had fathered three children, and 3.9% 

had fathered four or more children. A 

similar percent distribution of the number 

of biological children fathered by men 

occurred in 2006–2010. 

●	 In 2011–2015, the majority of men 

aged 15–24 had not had a biological 

child (92.4%), and at age 40–44, 

19.6% had not had a child. 

●	 Currently married men reported the 

highest mean number of children 

(1.7), followed by formerly married 

(1.4) and currently cohabiting 

(1.2) men. A higher percentage of 

currently married men fathered four 

or more biological children (7.5%) 

compared with currently cohabiting 

(5.2%) and never married (0.3%) 

 

Figure 2. Mean number of children ever born to women and men aged 22–44, by education: 

United States, 2011–2015 

 

 

 

 

 

addition, nearly one in four women 

with less than a high school diploma 

have had four or more children NOTES: The level of education was limited to persons aged 22–44 at the time of interview. Chi-square statistics for the 

number of children ever born or fathered by education were statistically significant (p < 0.05). (23.5%), which is more than twice SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 

the percentage of any other education 

group. 
National Health Statistics Reports  Number 113  July 11, 2018	 Page 5 

men, but the percentage was similar 

to formerly married (7.1%). 

●	 Men with no high school diploma 

or GED had fathered a higher mean 

number of children (1.8) compared 

with men who had a high school 

diploma (1.3) or those with some 

college (0.9) or a bachelor’s degree 

or higher (0.9). 

●	 Men aged 20–44 currently living in 

households with incomes of 300% 

of the federal poverty level or higher 

on average fathered 0.9 children 

compared with an average 1.3 

children for men living in households 

with incomes of 0%–149% of the 

federal poverty level and an average 

1.1 children for men living in 

households with incomes of 150%– 

299% of the federal poverty level. 

●	 Higher percentages of U.S.-born 

Hispanic men had not fathered 

a child (61.6%) compared with 

Hispanic men born outside of the 

United States (36.3%). Hispanic 

men (50.2%) were less likely to have 

not fathered a child compared with 

non-Hispanic white (57.7%) and 

non-Hispanic Asian (64.4%) men but 

were similar to non-Hispanic black 

men (53.4%). 

Timing of first birth 

Table 4 focuses on men and women 

who have had a child and shows their 

mean age at first birth, as well as the 

percent distribution by age at first birth. 

In 2011–2015, the mean age at first birth 

among women who had ever had a child 

was 23.1, which was similar to the mean 

age at first birth in 2006–2010 (23.0). The 

and 30.7% among those aged 25–29) 

and nearly one out of eight occurred 

among those under age 20 (13.8%). 

●	 Women aged 15–24 and 25–29 were 

more likely to have had a first birth 

before age 20 (61.3% and 35.3%, 

respectively) than older women 

(25.2%–27.2%). This same pattern 

did not exist among men. 

●	 A higher percentage of currently 

married women have had a first 

birth at age 30 and over (20.2%) 

than those who were not married 

(4.7%–8.2%). This relationship also 

holds for men. 

●	 College-educated women were more 

likely to have had a first birth at 

age 30 and over (35.0%) compared 

with women with lower levels of 

education (3.4%–9.6%). The same 

pattern holds for men. For both men 

and women aged 22–44, the higher 

the level of education, the lower the 

percentage who have had a first birth 

before age 20. For example, 53.9% 

of women who had less than a high 

school education have had a first 

birth before age 20 compared with 

5.5% of women with a bachelor’s 

degree or higher (Figure 3). 

●	 Women currently living in 

households with incomes of 300% 

of the federal poverty level or 

higher were more likely to have 

 

 

 

 

 

had a first birth at age 30 and over 

(29.0%) compared with women 

living in households with lower 

incomes (6.1%–10.3%). The same 

relationship holds for men. Men 

currently living in households with 

incomes of 300% of the federal 

poverty level or higher were more 

likely to have had a first birth at 

age 30 and over (35.2%) compared 

with those living in households with 

lower incomes (11.2%–18.9%). 

●	 The mean age at first birth among 

those who had ever had a child 

was highest for non-Hispanic 

Asian women (26.7), followed by 

non-Hispanic white (24.1), Hispanic 

(21.5), and non-Hispanic black 

(21.2) women. A similar pattern 

exists among men. 

Another way to examine the timing 

of first births in the U.S. population is to 

use life table methodology to calculate 

the cumulative probability of having 

had a birth by selected ages (Table 5 and 

Figure 4). In 2011–2015, the probability 

of a woman having had a birth was 8% 

by age 18 and 83% by age 40 (Figure 

4). For men, the probability of having 

fathered a child was 2% by age 18 and 

78% by age 40. Among those aged 

15–44, the probability of having a child 

by age 40 decreased among women from 

2006–2010 (85%) to 2011–2015 (83%) 

 

 

 

 

 

 

 

percentage of women whose first birth 

occurred at age 30 or over was similar 

in 2011–2015 (14.2%) to 2006–2010 

first births occurred among women 

 

 

 

 in their 20s (33.0% among those 

 

(13.6%). For men, the mean age at first 

birth in 2011–2015 (25.5) and 2006–2010 

(25.1) was similar.	 

 

● In 2011–2015, more than one-half of 

 

 

 aged 20–24 and 21.5% among those 

aged 25–29) and nearly one-third 

occurred at ages younger than 20 

(31.2%). About two-thirds of first 

NOTES: The level of education was limited to persons aged 22–44 at the time of interview. Distribution of age at first birth 

by education was statistically significant (p < 0.05). 

SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 

births occurred among men in their Figure 3. Percent distribution of age at first birth for women aged 22–44, by education: 

20s (32.4% among those aged 20–24 United States, 2011–2015 
 

 

Page 6	 National Health Statistics Reports  Number 113  July 11, 2018 

NOTE: Women had a higher cumulative probability of a first birth at each age than men (p < 0.05). 

SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 

 

Figure 4. Probability of a first birth, by selected age for women and men aged 15–44: 

United States, 2011–2015 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

and increased slightly for men (76% 

compared with 78%) (Table 5). 

●	 Women and men with lower levels 

of education were more likely to 

have had a child by age 20 than those 

with higher levels of education. For 

example, 50% of women who did 

not graduate from high school have 

had a birth by age 20 compared 

with 3% of those who had at least a 

college degree. 

●	 Women currently living in 

households with incomes less than 

150% of the federal poverty level 

were more likely to have had a 

birth by age 20 (33%) compared 

with women living with household 

incomes at 300% of the federal 

poverty level or higher (7%). Among 

men, those currently living with the 

highest household incomes relative 

to the federal poverty level were less 

likely to have fathered a child by 

age 20 (4%) compared with those 

with the lowest household incomes 

relative to the federal poverty level 

(12%). 

●	 There were significant differences 

by Hispanic origin and race in the 

probability of having had a first 

birth by age 20. Hispanic (28%) and 

non-Hispanic black (28%) women 

had a higher probability of having 

had a first birth by age 20, followed 

by non-Hispanic white (14%) and 

non-Hispanic Asian (4%) women. 

Non-Hispanic black men (12%) were 

most likely to have had a first birth 

by age 20, followed by Hispanic 

(9%), non-Hispanic white (5%), and 

non-Hispanic Asian (less than 1%) 

men. U.S.-born Hispanic men (8%) 

and women (27%) were less likely 

to have had a first birth by age 20 

than Hispanic men and women born 

outside of the United States (10% 

and 30%, respectively). 

Birth spacing 

Based on women aged 15–44 in 

2011–2015 who had at least one birth in 

their lifetime, Table 6 shows variations 

in birth spacing (or birth intervals) 

between their first and second birth (if 

any at the time of interview) by selected 

characteristics. The distribution of birth 

spacing in 2011–2015 is similar to that in 

2006–2010. 

●	 In 2011–2015, nearly one-third of 

women aged 15–44 in the United 

States with a birth had only one 

birth (31.7%). About one-third of 

women had their second birth within 

36 months of the first birth (22.8% 

within 26 months and 12.7% within 

27–36 months). About one-third of 

women had a second birth more than 

3 years after their first birth (10.2% 

within 37–48 months and 22.6% at 

49 or more months). 

●	 Higher percentages of women in 

older age groups at the time of their 

first birth did not have a second birth. 

For example, 50.3% of women aged 

30–44 at the time of their first birth 

did not have a second birth compared 

with 31.2% of women aged 20–24. 

●	 A higher percentage of women under 

age 20 at the time of their first birth 

had a second birth within 26 months 

of the first birth (26.1%) compared 

with women aged 20–24 (21.3%). 

●	 The percentage of women who had a 

second birth 49 months or more after 

their first birth decreased as their age 

at first birth increased. For example, 

29.1% of women under 20 at the 

time of their first birth had a second 

birth 49 months or later after their 

first birth compared with 7.8% of 

women aged 30–44. 

●	 The percentages of women who had 

a second birth within 26 months 

among those who were married 

(24.7%) or cohabiting (23.4%) at the 

time of their first birth were higher 

than the percentages for women who 

were formerly married (14.2%) or 

never married (18.8%). 

●	 A higher percentage of women 

who had never been married at 

the time of their first birth had a 

birth interval of 49 or more months 

(27.9%) compared with women who 

were married (19.9%) or cohabiting 

(22.4%) at the time of their first 

birth. 

●	 The percentage of women without 

a high school diploma or GED who 

had a second birth within 26 months 

of their first birth (29.7%) was 

similar to the percentage for women 

with a high school diploma or GED 

(25.1%). The percentage of women 

with some college but no bachelor’s 

degree who had a second birth within 

26 months of their first birth (19.8%) 

was similar to the percentage for 

women with a bachelor’s degree 

or higher (21.6%). The percentage 

of women with a high school 

diploma or GED who had a second 

birth within 26 months of their 

first birth (25.1%) was similar to 

the percentage for women with a 

bachelor’s degree or higher (21.6%). 

●	 About one in seven women with a 

bachelor’s degree or higher had a 

birth interval of 49 or more months 

(15.4%) compared with about one in 
National Health Statistics Reports  Number 113  July 11, 2018	 Page 7 

four women in the other education 

groups (25.4%–27.8%). 

●	 A higher percentage of women with 

higher household incomes relative 

to the federal poverty level did not 

have a second birth. For example, 

37.0% of women with household 

incomes at 300% or higher of the 

federal poverty level did not have a 

second birth compared with 27.6% 

of women with household incomes 

of less than 150% of the federal 

poverty level. 

●	 A higher percentage of women with 

household incomes of 0%–149% 

of the federal poverty level had a 

second birth within 26 months of 

their first birth (26.3%) compared 

with women with household incomes 

of 150%–299% of the federal 

poverty level (20.6%) or women 

with household incomes of 300% or 

higher of the federal poverty level 

(20.2%). 

●	 A higher percentage of women with 

household incomes relative to the 

federal poverty level of 0%–149% 

(23.4%) and 150%–299% (26.0%) 

had a second birth 49 months or 

more after their first birth compared 

with women with a household 

income of 300% or higher than the 

federal poverty level (19.5%). 

●	 The percentage of Hispanic women 

born in the United States who had 

a second birth within 26 months of 

their first birth (21.2%) was similar 

to the percentage among Hispanic 

women born outside of the United 

States (27.0%). The percentage 

of Hispanic women (regardless 

of nativity) who had a second 

birth within 26 months (24.2%) 

was similar to the percentage 

for non-Hispanic white (22.6%), 

non-Hispanic black (21.7%), 

and non-Hispanic Asian (17.6%) 

women. The only comparison 

among all Hispanic-origin and race 

groups shown for women that was 

statistically significant was a higher 

percentage of Hispanic women 

born outside of the United States 

who had a second birth within 26 

months (27.0%) compared with 

non-Hispanic Asian women (17.6%). 

●	 The percentage of Hispanic women 

born in the United States who had a 

second birth 49 months or later after 

their first birth (25.1%) was similar 

to the percentage among Hispanic 

women born outside of the United 

States (31.2%). The percentage 

of Hispanic women (regardless of 

nativity) who had a second birth 

49 months or later after their first 

birth (28.2%) was higher than 

the percentage for non-Hispanic 

white (20.9%), non-Hispanic black 

(22.1%), and non-Hispanic Asian 

(19.3%) women. 

Summary 

This report presents selected fertility 

indicators for men and women aged 

15–44 in the United States based on 

2011–2015 NSFG data. Measures of 

fertility include having had any biological 

children, the number of biological 

children, age at first child’s birth, and 

birth intervals for women with at least 

one child. The fertility experience of 

men and women differs across various 

characteristics, including education, 

household income relative to the federal 

poverty level, and Hispanic origin and 

race. The overall results reported for 

2011–2015 are generally similar to those 

based on the 2006–2010 NSFG. 

In 2011–2015, 54.9% of women and 

43.8% of men aged 15–44 in the United 

States had a biological child. The mean 

number of births reported by women 

aged 15–44 in 2011–2015 was 1.2, and 

the mean number of births reported by 

men aged 15–44 was 0.9. 

Among men and women aged 

15–44 in 2011–2015 who had ever had 

a biological child, the mean age at first 

birth (25.5 and 23.1, respectively) was 

statistically unchanged from 2006–2010. 

Among women, about one-third had their 

first birth in their teens, and more than 

one-half had them in their 20s. Among 

men, one in six fathered their first child in 

their teens, and two-thirds fathered them 

in their 20s. This difference may also 

be explained in part by age differences 

between women and men in sexual 

relationships (27). 

The frequently documented 

differences in birth rates and birth timing 

by Hispanic origin and race continue 

(1,3,28). On average, the number of 

children ever born is highest for Hispanic 

women followed by non-Hispanic 

black and non-Hispanic white women, 

which is explained partly by a higher 

age at first birth for non-Hispanic 

white women compared with Hispanic 

and non-Hispanic black women. In 

2011–2015, non-Hispanic white women 

had the fewest number of children and the 

oldest mean age at first birth compared 

with Hispanic women and non-Hispanic 

black women. However, non-Hispanic 

Asian women had the highest mean age 

at first birth. These differences may be 

explained in part by differences in age 

structure among these different groups. 

The probability of having a first birth 

before age 20 is highest for Hispanic and 

non-Hispanic black women and lowest 

for non-Hispanic Asian women. Among 

men, the probability of fathering a baby 

before age 20 is highest for non-Hispanic 

black men, followed by Hispanic, 

non-Hispanic white, and non-Hispanic 

Asian men. 

Looking at differences by 

educational attainment, men and women 

with lower levels of education were 

more likely to have had a birth, to have 

had more children, and to have had their 

first child at younger ages compared 

with men and women with higher levels 

of education. As mentioned earlier, 

education was measured at the time of 

interview, not at the time of the child’s 

birth, so the bivariate association seen in 

cross-sectional data like NSFG may be 

due partly to early childbearing curtailing 

additional education for younger parents. 

In presenting these key findings 

on selected fertility measures for men 

and women in the United States, some 

limitations of the data must be noted. 

Some measures are assessed at the time 

of interview, such as household income 

relative to the federal poverty level, 

and may not reflect cause-and-effect 

relationships. Bivariate associations 

described in this report may be explained 

by age and other characteristics included 

or not included in this report. The 

2011–2015 pooled NSFG data do not 

include persons over the age of 44 and 

may not describe completed fertility 

for men or women nor information 

about birth spacing among later child 

bearers, because the birth of their next 

child may occur past the survey’s age 
Page 8	 National Health Statistics Reports  Number 113  July 11, 2018 

range. In addition, the age range of the 

NSFG does not allow for examination 

of birth spacing or completed fertility 

of women who start childbearing at a 

later age and who may go on to have 

the same number of children as women 

who started childbearing at an earlier 

age. Similarly, these fertility measures 

may be particularly incomplete for men, 

because men are more likely than women 

to father children after age 44. Starting 

in the fall of 2015, the NSFG age range 

was expanded from 15–44 to 15–49, 

which will allow future descriptions and 

analyses of fertility to cover more of 

the upper end of the reproductive years. 

Nonetheless, the NSFG is a rich source 

of data on proximate determinants of 

fertility, which help explain variations 

in birth rates obtained from the National 

Vital Statistics System. 

References 

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2017. Available from: https://www.cdc. 

gov/nchs/data/nvsr/nvsr66/nvsr66_01.pdf. 

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https://www.cdc.gov/nchs/data/databriefs/ 

db240.pdf. 

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of causal relationships in population 

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14. Power To Decide. Progress pays off. 

Washington, DC. 2018. Available from: 

https://powertodecide.org/sites/default/ 

files/media/savings-fact-sheet-national. 

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15. Mathews TJ, Hamilton BE. First births to 

older women continue to rise. NCHS Data 

Brief, no 152. Hyattsville, MD: National 

Center for Health Statistics. 2014. 

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in U.S. fertility. Washington, DC. 2017. 

Available from: https://www.prb.org/ 

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aspx. 

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Center for Health Statistics. 2018. 

18. Population Reference Bureau. Birth 

spacing and childhood undernutrition. 

Washington, DC. 2009. Available from: 

https://www.prb.org/Publications/ 

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depletion and poor outcomes increases in 

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133(5 Suppl 2):1732S–1736S. 2003. 

21. Conde-Agudelo A, Rosas-Bermúdez A, 

Kafury-Goeta AC. Birth spacing and risk 

of adverse perinatal outcomes: A metaanalysis. JAMA 295(15):1809–23. 2006. 

22. Conde-Agudelo A, Rosas-Bermúdez A, 

Castaño F, Norton MH. Effects of birth 

spacing on maternal, perinatal, infant, and 

child health: A systematic review of causal 

mechanisms. Stud Fam Plan 43(2): 

93–114. 2012. 

23. Bongaarts J. A framework for analyzing 

the proximate determinants of fertility. 

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MD. Available from: https://www.cdc. 

gov/nchs/data/nsfg/nsfg_2011_2013_ 

designanddatacollectionmethods.pdf. 

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omb/fedreg_1997standards. 

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27. Goodwin PY, Mosher WD, Chandra A. 

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States: A statistical portrait based on Cycle 

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in the non-marital fertility rates in 

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34(1):141–59. 2014. 
National Health Statistics Reports  Number 113  July 11, 2018 Page 9 

Table 1. Percentage of women and men aged 15–44 who ever had a biological child: United States, 2011–2015 

Women Men 

Number Percent Number Percent 

Characteristic (thousands) (standard error) (thousands) (standard error) 

Total1 

2011–2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61,263 54.9 (0.90) 60,875 43.8 (0.92) 

2006–2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61,755 55.6 (1.09) 62,128 44.8 (1.06) 

Age group 

15–24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19,937 17.1 (1.02) 20,596 7.6 (0.72) 

25–29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,550 52.1 (1.83) 10,472 37.2 (1.82) 

30–34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,540 76.2 (1.59) 10,290 58.6 (1.75) 

35–39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,787 80.0 (1.69) 9,462 74.8 (1.88) 

40–44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,449 85.0 (1.21) 10,055 80.4 (1.48) 

Marital or cohabiting status 

Currently married . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23,342 80.4 (1.14) 22,041 80.0 (1.20) 

Currently cohabiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,035 59.4 (1.99) 8,078 54.6 (2.25) 

Never married, not cohabiting. . . . . . . . . . . . . . . . . . . . . . . 23,787 21.3 (1.05) 27,648 8.8 (0.62) 

Formerly married, not cohabiting . . . . . . . . . . . . . . . . . . . . 5,099 86.8 (1.52) 3,107 70.1 (2.40) 

Education2 

No high school diploma or GED . . . . . . . . . . . . . . . . . . . . . 4,786 93.3 (1.07) 6,130 74.4 (2.40) 

High school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . 11,422 80.7 (1.24) 13,205 61.8 (1.48) 

Some college, no bachelor’s degree . . . . . . . . . . . . . . . . . 14,601 66.8 (1.33) 13,822 49.4 (1.77) 

Bachelor’s degree or higher . . . . . . . . . . . . . . . . . . . . . . . . 16,813 53.8 (1.54) 13,448 48.9 (2.00) 

Percent of federal poverty level3 

0–149 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19,371 75.0 (1.33) 14,147 57.1 (1.74) 

150–299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13,175 63.6 (1.32) 14,162 53.6 (1.74) 

300 or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19,235 54.0 (1.45) 22,569 47.9 (1.59) 

Hispanic origin and race 

Hispanic or Latino. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12,303 62.1 (1.30) 12,908 49.8 (1.66) 

Native born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,311 50.4 (1.79) 7,090 38.4 (2.17) 

Foreign born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,991 79.3 (1.71) 5,818 63.7 (2.61) 

Not Hispanic or Latino 

White, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34,087 53.0 (1.24) 34,304 42.3 (1.23) 

Black or African American, single race . . . . . . . . . . . . . . 8,407 57.1 (1.39) 7,286 46.6 (2.00) 

Asian, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,161 48.9 (3.94) 3,180 35.6 (3.32) 

1

Includes persons of other or multiple race and origin groups, not shown separately.
 

2

Limited to persons aged 22–44 at the time of interview.
 

3

Limited to persons aged 20–44 at the time of interview.
 

NOTE: Chi-square statistics for “ever had a biological child” were statistically significant (p < 0.05). 

SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 
Table 2. Number of children born to women aged 15–44: United States, 2011–2015 

Number Mean None One Two Th

Characteristic (thousands) (standard error) Total (standard error) (standard error) (standard error) (standa

Total1 Percent distribution 

2011–2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61,263 1.2 (0.02) 100.0 45.1 (0.90) 17.1 (0.47) 19.7 (0.60) 11.9 

2006–2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61,755 1.3 (0.03) 100.0 44.4 (1.09) 16.2 (0.54) 21.0 (0.75) 11.5 

Age group 

15–24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19,937 0.2 (0.02) 100.0 82.9 (1.02) 11.6 (0.71) 4.0 (0.40) 1.4 

25–29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,550 1.0 (0.04) 100.0 47.9 (1.83) 22.5 (1.10) 16.0 (1.19) 9.9 30–34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,540 1.7 (0.05) 100.0 23.8 (1.59) 22.5 (1.31) 27.3 (1.53) 17.4 35–39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,787 1.9 (0.06) 100.0 20.0 (1.69) 16.9 (1.17) 32.8 (1.68) 19.3 40–44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,449 2.1 (0.05) 100.0 15.0 (1.21) 16.8 (1.35) 33.7 (1.78) 22.0 

Marital or cohabiting status 

Currently married . . . . . . . . . . . . . . . . . . . . . . . 23,342 1.8 (0.03) 100.0 19.6 (1.14) 20.4 (0.89) 33.3 (1.17) 18.4 Currently cohabiting . . . . . . . . . . . . . . . . . . . . . 9,035 1.2 (0.05) 100.0 40.6 (1.99) 23.1 (1.42) 17.9 (1.25) 11.2 

Never married, not cohabiting. . . . . . . . . . . . . . 23,787 0.4 (0.02) 100.0 78.7 (1.05) 10.5 (0.63) 5.4 (0.41) 3.5 Formerly married, not cohabiting . . . . . . . . . . . 5,099 2.1 (0.06) 100.0 13.2 (1.52) 22.0 (1.75) 27.7 (2.23) 23.3 

Education2 

No high school diploma or GED . . . . . . . . . . . . 4,786 2.6 (0.06) 100.0 6.7 (1.07) 16.2 (1.69) 26.1 (1.96) 27.4 

High school diploma or GED . . . . . . . . . . . . . . 11,422 1.9 (0.05) 100.0 19.3 (1.24) 21.4 (1.26) 27.6 (1.34) 20.2 Some college, no bachelor’s degree . . . . . . . . 14,601 1.4 (0.04) 100.0 33.2 (1.33) 21.2 (1.03) 24.9 (1.32) 14.9 

Bachelor’s degree or higher . . . . . . . . . . . . . . . 16,813 1.0 (0.04) 100.0 46.2 (1.54) 19.0 (1.20) 23.1 (1.26) 8.9 

Percent of federal poverty level3 

0–149 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19,371 1.8 (0.05) 100.0 25.0 (1.33) 20.3 (0.83) 22.9 (0.93) 18.5 

150–299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13,175 1.4 (0.04) 100.0 36.4 (1.32) 18.6 (1.07) 24.9 (1.41) 14.7 

300 or higher . . . . . . . . . . . . . . . . . . . . . . . . . . 19,235 1.0 (0.04) 100.0 46.0 (1.45) 19.5 (1.07) 22.6 (1.20) 9.3 

Hispanic origin and race 

Hispanic or Latina. . . . . . . . . . . . . . . . . . . . . . . 12,303 1.5 (0.04) 100.0 37.9 (1.30) 16.6 (1.07) 20.4 (1.09) 15.2 

Native born . . . . . . . . . . . . . . . . . . . . . . . . . . 7,311 1.1 (0.05) 100.0 49.6 (1.79) 16.8 (1.42) 17.0 (1.36) 9.6 Foreign born . . . . . . . . . . . . . . . . . . . . . . . . . 4,991 2.0 (0.07) 100.0 20.7 (1.71) 16.3 (1.77) 25.4 (1.89) 23.5 

Not Hispanic or Latina 

White, single race . . . . . . . . . . . . . . . . . . . . . 34,087 1.1 (0.03) 100.0 47.0 (1.24) 16.4 (0.71) 21.0 (0.91) 11.5 

Black or African American, single race . . . . . 8,407 1.3 (0.05) 100.0 42.9 (1.39) 20.5 (1.27) 15.3 (0.94) 11.4 Asian, single race . . . . . . . . . . . . . . . . . . . . . 3,163 0.9 (0.10) 100.0 51.1 (3.94) 18.2 (2.41) 21.4 (3.14) 5.5 

* Figure does not meet standards of reliability or precision.
 1Includes persons of other or multiple race and origin groups, not shown separately.
 2Limited to persons aged 22–44 at the time of interview.
 3Limited to persons aged 20–44 at the time of interview.
 

NOTES: Percentages may not add to 100 due to rounding. Chi-square statistics for each variable by number of children born were statistically significant (p < 0.05). SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 
Table 3. Number of biological children fathered by men aged 15–44: United States, 2011–2015 

Number Mean None One Two T

Characteristic (thousands) (standard error) Total (standard error) (standard error) (standard error) (stand

Total1 Percent distribution 

2011–2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60,875 0.9 (0.02) 100.0 56.2 (0.92) 15.6 (0.58) 16.2 (0.66) 8.1 2006–2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62,128 0.9 (0.02) 100.0 55.2 (1.06) 15.8 (0.64) 17.0 (0.71) 7.9 

Age group 

15–24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20,596 0.1 (0.01) 100.0 92.4 (0.72) 5.8 (0.68) 1.4 (0.21) 0.5 25–29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,472 0.6 (0.04) 100.0 62.8 (1.82) 21.1 (1.42) 10.8 (1.12) 4.0 30–34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,290 1.2 (0.05) 100.0 41.4 (1.75) 21.0 (1.43) 22.0 (1.52) 11.1 35–39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,462 1.7 (0.06) 100.0 25.2 (1.88) 20.0 (1.83) 32.7 (2.05) 14.1 

40–44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,055 1.9 (0.05) 100.0 19.6 (1.48) 20.2 (1.44) 30.9 (1.89) 19.2 

Marital or cohabiting status 

Currently married . . . . . . . . . . . . . . . . . . . . . . . . . 22,041 1.7 (0.04) 100.0 20.0 (1.20) 22.4 (1.06) 33.2 (1.37) 17.0 Currently cohabiting . . . . . . . . . . . . . . . . . . . . . . . 8,078 1.2 (0.05) 100.0 45.4 (2.25) 25.5 (2.00) 15.9 (1.46) 7.9 Never married, not cohabiting. . . . . . . . . . . . . . . . 27,648 0.1 (0.01) 100.0 91.2 (0.62) 6.2 (0.51) 1.6 (0.20) 0.7 Formerly married, not cohabiting . . . . . . . . . . . . . 3,107 1.4 (0.06) 100.0 29.9 (2.40) 25.1 (2.19) 26.9 (2.30) 10.9 

Education2 

No high school diploma or GED . . . . . . . . . . . . . . 6,130 1.8 (0.09) 100.0 25.6 (2.40) 21.1 (1.94) 26.4 (2.05) 13.8 

High school diploma or GED . . . . . . . . . . . . . . . . 13,205 1.3 (0.04) 100.0 38.2 (1.48) 23.2 (1.28) 21.0 (1.42) 12.3 

Some college, no bachelor’s degree . . . . . . . . . . 13,822 0.9 (0.04) 100.0 50.6 (1.77) 18.6 (1.14) 18.2 (1.29) 8.8 

Bachelor’s degree or higher . . . . . . . . . . . . . . . . . 13,448 0.9 (0.05) 100.0 51.1 (2.00) 15.4 (1.27) 21.8 (1.51) 9.0 

Percent of federal poverty level3 

0–149 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,147 1.3 (0.05) 100.0 42.9 (1.74) 19.1 (1.32) 17.3 (1.22) 11.8 

150–299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,162 1.1 (0.05) 100.0 46.4 (1.74) 19.1 (1.21) 20.0 (1.32) 9.6 

300 or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22,569 0.9 (0.04) 100.0 52.1 (1.59) 17.3 (0.93) 20.4 (1.12) 8.4 

Hispanic origin and race 

Hispanic or Latino. . . . . . . . . . . . . . . . . . . . . . . . . 12,908 1.1 (0.04) 100.0 50.2 (1.66) 15.8 (1.34) 18.2 (1.25) 9.6 

Native born . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,090 0.8 (0.06) 100.0 61.6 (2.17) 13.2 (1.28) 14.5 (1.33) 7.4 

Foreign born . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,818 1.5 (0.08) 100.0 36.3 (2.61) 19.0 (2.37) 22.8 (1.99) 12.3 

Not Hispanic or Latino 

White, single race . . . . . . . . . . . . . . . . . . . . . . . 34,304 0.8 (0.03) 100.0 57.7 (1.23) 15.0 (0.76) 16.9 (0.92) 7.7 

Black or African American, single race . . . . . . . 7,286 1.0 (0.05) 100.0 53.4 (2.00) 17.7 (1.37) 14.4 (1.30) 9.0 

Asian, single race . . . . . . . . . . . . . . . . . . . . . . . 3,180 0.8 (0.80) 100.0 64.4 (3.32) 17.2 (2.58) 10.8 (1.88) 

* Figure does not meet standards of reliability or precision.
 1Includes persons of other or multiple race and origin groups, not shown separately.
 2Limited to persons aged 22–44 at the time of interview.
 3Limited to persons aged 20–44 at the time of interview.
 

NOTES: Percentages may not add to 100 due to rounding. Chi-square statistics for each variable by number of children fathered were statistically significant (p < 0.05). SOURCE:NCHS, National Survey of Family Growth, 2011–2015. 
Table 4. Age at first child’s birth for women and men aged 15–44: United States, 2011–2015 

Women 

Number Mean Under 20 20–24 25–2

Characteristic (thousands) (standard error) Total (standard error) (standard error) (standard 

Total1 Percent distribution 

2011–2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33,645 23.1 (0.16) 100.0 31.2 (1.20) 33.0 (0.92) 21.5 (

2006–2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34,353 23.0 (0.16) 100.0 31.1 (1.14) 34.5 (1.06) 20.7 (

Age group 

15–24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,401 18.9 (0.12) 100.0 61.3 (2.93) 38.7 (2.93) ... 

25–29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,500 21.1 (0.13) 100.0 35.3 (1.84) 46.7 (1.93) 18.0 (30–34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,032 23.1 (0.18) 100.0 27.2 (1.66) 35.3 (1.60) 25.9 (

35–39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,833 24.1 (0.26) 100.0 26.3 (1.91) 28.5 (1.96) 24.6 (40–44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,878 25.0 (0.30) 100.0 25.2 (2.13) 24.5 (1.72) 25.0 (

Marital or cohabiting status 

Currently married . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18,778 24.7 (0.18) 100.0 19.2 (1.23) 31.2 (1.20) 29.4 (

Currently cohabiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,368 21.1 (0.24) 100.0 43.8 (2.46) 38.4 (2.18) 10.5 (Never married, not cohabiting. . . . . . . . . . . . . . . . . . . . . . . . . . . 5,074 20.3 (0.17) 100.0 51.8 (2.23) 34.9 (1.99) 8.6 (

Formerly married, not cohabiting . . . . . . . . . . . . . . . . . . . . . . . . 4,425 21.6 (0.27) 100.0 43.6 (2.51) 32.5 (2.30) 15.7 (

 Education 2 

No high school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . 4,465 20.1 (0.16) 100.0 53.9 (2.01) 34.4 (1.86) 8.3 (

High school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,219 21.1 (0.16) 100.0 42.5 (1.90) 39.3 (1.54) 12.4 (

Some college, no bachelor’s degree . . . . . . . . . . . . . . . . . . . . . 9,754 22.7 (0.17) 100.0 28.1 (1.70) 42.5 (1.72) 19.8 (

Bachelor’s degree or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,043 27.8 (0.23) 100.0 5.5 (1.10) 17.7 (1.81) 41.7 (

Percent of federal poverty level3 

0–149 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,786 21.0 (0.13) 100.0 44.7 (1.42) 36.8 (1.25) 12.4 (

150–299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,445 22.8 (0.19) 100.0 29.2 (1.74) 39.0 (1.68) 21.5 (300 or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,414 26.3 (0.21) 100.0 13.8 (1.27) 22.9 (1.67) 34.3 (

Hispanic origin and race 

Hispanic or Latina. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,646 21.5 (0.17) 100.0 40.6 (1.88) 36.3 (1.74) 15.1 (

Native born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,688 21.0 (0.25) 100.0 45.4 (2.78) 34.0 (2.14) 13.0 (Foreign born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,957 22.0 (0.18) 100.0 36.2 (2.00) 38.5 (2.40) 17.1 (

Not Hispanic or Latina 

White, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18,065 24.1 (0.24) 100.0 24.8 (1.56) 31.1 (1.27) 26.2 (Black or African American, single race . . . . . . . . . . . . . . . . . . 4,802 21.2 (0.20) 100.0 44.9 (2.29) 36.0 (2.27) 10.8 (Asian, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,545 26.7 (0.46) 100.0 7.2 (2.03) 27.6 (5.28) 38.0 (

See footnotes at end of table. 
Table 4. Age at first child’s birth for women and men aged 15–44: United States, 2011–2015 —Con. 

Men 

Number Mean Under 20 20–24 25–2

Characteristic (thousands) (standard error) Total (standard error) (standard error) (standard 

Total1 Percent distribution 

2011–2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26,661 25.5 (0.16) 100.0 13.8 (0.87) 32.4 (1.30) 30.7 (

2006–2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27,821 25.1 (0.15) 100.0 14.6 (0.83) 35.4 (1.29) 29.8 (

Age group 

15–24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,572 19.7 (0.20) 100.0 45.2 (4.31) 54.8 (4.31) ... 

25–29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,893 22.8 (0.15) 100.0 14.9 (2.00) 53.3 (2.83) 31.8 (30–34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,031 24.7 (0.20) 100.0 15.6 (1.92) 31.5 (2.51) 37.3 (

35–39 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,079 26.7 (0.28) 100.0 8.5 (1.29) 26.8 (2.10) 35.3 (40–44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,085 27.6 (0.28) 100.0 10.6 (1.63) 23.4 (1.85) 27.0 (

Marital or cohabiting status 

Currently married . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17,642 26.6 (0.22) 100.0 9.6 (1.08) 26.9 (1.80) 34.4 (

Currently cohabiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,407 23.2 (0.25) 100.0 23.3 (2.27) 44.0 (3.12) 22.9 (Never married, not cohabiting. . . . . . . . . . . . . . . . . . . . . . . . . . . 2,434 22.8 (0.34) 100.0 27.1 (2.87) 44.8 (3.32) 18.4 (Formerly married, not cohabiting . . . . . . . . . . . . . . . . . . . . . . . . 2,178 24.5 (0.32) 100.0 14.5 (2.06) 39.5 (3.04) 29.8 (

 Education 2 

No high school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . 4,559 22.9 (0.23) 100.0 23.1 (2.36) 46.8 (2.93) 22.1 (

High school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,158 24.1 (0.19) 100.0 17.9 (1.54) 41.8 (2.03) 26.6 (Some college, no bachelor’s degree . . . . . . . . . . . . . . . . . . . . . 6,834 25.6 (0.23) 100.0 10.1 (1.44) 32.9 (2.41) 37.5 (Bachelor’s degree or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,570 29.7 (0.25) 100.0 1.1 (0.44) 10.8 (1.29) 37.0 (

Percent of federal poverty level3 

0–149 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,213 23.4 (0.18) 100.0 21.8 (1.66) 44.3 (2.14) 22.8 (

150–299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,617 25.1 (0.21) 100.0 13.5 (1.33) 34.9 (2.19) 32.7 (300 or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,831 27.5 (0.28) 100.0 8.1 (1.16) 21.6 (1.78) 35.2 (

Hispanic origin and race 

Hispanic or Latino. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,432 24.3 (0.22) 100.0 16.4 (1.54) 41.1 (2.20) 26.7 (

Native born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,724 24.2 (0.39) 100.0 18.3 (2.19) 40.4 (3.13) 25.5 (Foreign born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,709 24.4 (0.29) 100.0 15.1 (2.04) 41.7 (3.11) 27.5 (

Not Hispanic or Latino 

White, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,506 26.3 (0.23) 100.0 10.1 (1.08) 28.6 (1.80) 34.5 (Black or African American, single race . . . . . . . . . . . . . . . . . . 3,396 23.8 (0.40) 100.0 22.8 (2.06) 37.6 (2.82) 25.0 (Asian, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,132 29.9 (0.84) 100.0 0.4 (0.31) * 27.6 (

... Category not applicable. * Figure does not meet standards of reliability or precision.
 1Includes persons of other or multiple race and origin groups, not shown separately.
 2Limited to persons aged 22–44 at the time of interview.
 3Limited to persons aged 20–44 at the time of interview.
 

NOTES: Percentages may not add to 100 due to rounding. Chi-square statistics for each variable by age at first birth were statistically significant (p < 0.05). SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 
Table 5. Probability of a first birth, by selected ages for women and men aged 15–44: United States, 2011–2015 

Women Men 

Characteristic 18 20 25 30 35 40 18 20 25 

Total1 

2011–2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.08 0.19 0.43 0.63 0.78 0.83 0.02 0.07 0.26 

2006–2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.08 0.19 0.45 0.65 0.80 0.85 0.02 0.07 0.29 

 Education2 

No high school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 0.50 0.83 0.92 0.96 0.97 0.05 0.17 0.53 

High school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.14 0.34 0.67 0.80 0.89 0.90 0.03 0.11 0.38 

Some college, no bachelor’s degree . . . . . . . . . . . . . . . . . . . . . 0.07 0.19 0.49 0.68 0.79 0.85 0.01 0.05 0.23 

Bachelor’s degree or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01 0.03 0.13 0.41 0.66 0.74 0.00 0.01 0.06 

Percent of federal poverty level3 

0–149 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.15 0.33 0.65 0.80 0.89 0.92 0.04 0.12 0.41 

150–299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.07 0.18 0.46 0.68 0.81 0.86 0.01 0.07 0.28 

300 or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 0.07 0.21 0.45 0.66 0.73 0.01 0.04 0.15 

Hispanic origin and race 

Hispanic or Latino. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.13 0.28 0.59 0.76 0.86 0.89 0.03 0.09 0.37 

Native born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.13 0.27 0.54 0.69 0.81 0.85 0.03 0.08 0.32 

Foreign born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.13 0.30 0.65 0.82 0.90 0.93 0.02 0.10 0.42 

Not Hispanic or Latino 

White, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05 0.14 0.36 0.59 0.76 0.82 0.01 0.05 0.21 

Black or African American, single race . . . . . . . . . . . . . . . . . . 0.13 0.28 0.56 0.68 0.77 0.82 0.04 0.12 0.37 

Asian, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01 0.04 0.20 0.48 0.69 0.78 0.00 0.00 0.09 

0.00 Quantity more than zero but less than 0.05.
 1Includes persons of other or multiple race and origin groups, not shown separately.
 2Limited to persons aged 22–44 at the time of interview.
 3Limited to persons aged 20–44 at the time of interview.
 

NOTES: Probabilities in this table are produced using the life table methodology. All standard errors are p < 0.001. SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 
Table 6. Number of months from first birth to second birth for women aged 15–44: United States, 2011–2015 

Interval between first and second b

Number No second birth 26 or less 27–36 37–48 

Characteristic (thousands) Total (standard error) (standard error) (standard error) (standard 

Total2 Percent distribution 

2011–2015. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33,645 100.0 31.7 (0.78) 22.8 (0.84) 12.7 (0.65) 10.2 (02006–2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34,334 100.0 30.0 (0.96) 23.2 (0.87) 14.0 (0.59) 12.3 (0

Age group at first birth 

Under age 20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,507 100.0 20.9 (1.31) 26.1 (1.53) 11.7 (0.96) 12.2 (120–24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11,121 100.0 31.2 (1.39) 21.3 (1.25) 11.9 (1.04) 8.9 (0

25–29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,220 100.0 35.8 (1.78) 21.4 (1.97) 15.5 (1.58) 10.7 (130–44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,796 100.0 50.3 (2.72) 21.0 (2.35) 12.5 (1.77) 8.4 (1

 Marital or cohabiting status at first birth 

Married . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16,337 100.0 29.5 (1.24) 24.7 (1.26) 15.2 (1.09) 10.8 (0

Cohabiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,685 100.0 35.6 (1.57) 23.4 (1.61) 10.8 (0.92) 7.9 (0

Formerly married . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 100.0 * 14.2 (4.26) * * Never married. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,089 100.0 31.0 (1.56) 18.8 (1.35) 10.5 (0.99) 11.8 (1

 Education3 

No high school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . . 4,465 100.0 17.6 (1.80) 29.7 (1.92) 14.2 (1.38) 10.7 (1High school diploma or GED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,219 100.0 27.0 (1.52) 25.1 (1.73) 10.8 (0.90) 11.6 (1Some college, no bachelor’s degree . . . . . . . . . . . . . . . . . . . . . . 9,754 100.0 32.4 (1.49) 19.8 (1.34) 11.9 (1.13) 9.2 (0

Bachelor’s degree or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9,043 100.0 36.2 (2.09) 21.6 (1.99) 16.1 (1.69) 10.8 (1

Percent of federal poverty level4 

0–149 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,529 100.0 27.6 (1.10) 26.3 (1.10) 11.7 (0.68) 11.0 (0150–299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8,384 100.0 29.9 (1.66) 20.6 (1.60) 13.7 (1.33) 9.8 (1300 or higher . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10,380 100.0 37.0 (1.79) 20.2 (1.70) 13.6 (1.60) 9.8 (1

Hispanic origin and race 

Hispanic or Latina. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,646 100.0 27.1 (1.65) 24.2 (1.95) 11.8 (1.13) 8.7 (0

Native born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,688 100.0 33.7 (2.41) 21.2 (2.15) 9.7 (1.78) 10.4 (1Foreign born . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,957 100.0 20.9 (2.20) 27.0 (2.54) 13.7 (1.75) 7.2 (1

Not Hispanic or Latina 

White, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18,065 100.0 31.9 (1.17) 22.6 (1.12) 13.9 (0.98) 10.8 (0Black or African American, single race . . . . . . . . . . . . . . . . . . . 4,802 100.0 36.4 (2.07) 21.7 (1.52) 10.9 (1.37) 8.9 (1Asian, single race . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,545 100.0 37.2 (4.23) 17.6 (3.29) 10.8 (2.69) 15.1 (3

* Figure does not meet standards of reliability or precision (see Technical Notes for more information).
 1Refers to intervals between deliveries, not intervals between first and second babies born as a multiple birth. Pregnancies resulting in multiple births (e.g., twins) are considered one delivery.
 2Includes women of other or multiple race and origin groups, not shown separately.
 3Limited to women aged 22–44 at the time of interview.
 4Limited to women aged 20–44 at the time of interview.
 

NOTES: Percentages may not add to 100 due to rounding. Chi-square tests for differences across groups were statistically significant (p < 0.05). Includes women aged 15–44 at the time of interview during 2011–2015. Firat any time in the woman’s life and are not limited to specific years. SOURCE: NCHS, National Survey of Family Growth, 2011–2015. 
 

 

 

Page 16 National Health Statistics Reports  Number 113  July 11, 2018 

Technical Notes 

The Table compares the numbers of 

births estimated for 2007–2011 based on 

2011–2015 data from the National Survey 

of Family Growth (NSFG) and annual 

data from the National Center for Health 

Statistics’ National Vital Statistics System 

(NVSS). The Table is an assessment of 

NSFG data quality on births, since NVSS 

data represents all births registered in the 

vital records system in the United States. 

Given that the U.S. birth registration 

system only includes births occurring 

within the United States, the NSFG 

estimates for women in this comparison 

are limited to births to women who were 

born in the United States or for births 

that occurred after women who were 

born outside the United States came to 

stay in the United States. Across all years 

and population subgroups shown, NSFG 

data do not differ significantly from the 

number of births recorded in NVSS. The 

numbers based on vital records fall within 

the 95% confidence intervals for all the 

NSFG estimates shown, suggesting that 

the NSFG-based estimates are reasonably 

valid. 

Information from NVSS was 

obtained using the Centers for Disease 

Control and Prevention’s WONDER 

databases available at: https://wonder. 

cdc.gov/. The databases do not include 

information on paternal characteristics, 

therefore only maternal characteristics are 

shown. Beyond this technical limitation, 

comparisons of information about fathers 

from birth certificates represent a less 

precise benchmark to male survey reports 

in general, such as those from NSFG, 

since mothers report information for 

the birth registration system, and not all 

mothers report information about the 

fathers of their babies. 

Table. Number of births estimated for 2007–2011, based on the 2011–2015 National Survey 

of Family Growth and vital records 

Number Ratio of 

(thousands) of 95% confidence Vital NSFG and 

Characteristic births from NSFG interval records1 vital records 

Total2 

1991–1994 . . . . . . . . . . . . . . . . . . . . 15,932 14,935–16,929 16,129 0.99 

1997–2001 . . . . . . . . . . . . . . . . . . . . 20,394 18,896–21,892 19,800 1.03 

2002–2006 . . . . . . . . . . . . . . . . . . . . 21,084 19,205–22,963 20,597 1.02 

2007–2011 . . . . . . . . . . . . . . . . . . . . 20,184 18,591–21,776 20,610 0.98 

Birth year 

2011 . . . . . . . . . . . . . . . . . . . . . . . . . 3,850 3,395–4,304 3,946 0.98 

2010 . . . . . . . . . . . . . . . . . . . . . . . . . 3,890 3,462–4,317 3,992 0.97 

2009 . . . . . . . . . . . . . . . . . . . . . . . . . 4,121 3,696–4,547 4,123 1.00 

2008 . . . . . . . . . . . . . . . . . . . . . . . . . 4,101 3,601–4,601 4,240 0.97 

2007 . . . . . . . . . . . . . . . . . . . . . . . . . 4,222 3,758–4,686 4,309 0.98

 Hispanic origin and race 

Hispanic or Latino. . . . . . . . . . . . . . . 4,858 4,069–5,647 4,961 0.98 

Not Hispanic or Latino 

White. . . . . . . . . . . . . . . . . . . . . . . 11,214 9,888–12,540 11,077 1.01 

Black or African American. . . . . . . 2,623 2,142–3,103 3,027 0.87 

Marital status at birth 

Married . . . . . . . . . . . . . . . . . . . . . . . 11,499 10,321–12,678 12,240 0.94 

Unmarried. . . . . . . . . . . . . . . . . . . . . 8,684 7,872–9,496 8,369 1.04 

Age group at birth 

15–19 . . . . . . . . . . . . . . . . . . . . . . . . 2,021 1,690–2,351 1,987 1.02 

20–24 . . . . . . . . . . . . . . . . . . . . . . . . 5,053 4,531–5,575 5,017 1.01 

25–44 . . . . . . . . . . . . . . . . . . . . . . . . 13,088 11,840–14,336 13,579 0.96 

25–29 . . . . . . . . . . . . . . . . . . . . . . 5,898 5,248–6,547 5,832 1.01 

30–44 . . . . . . . . . . . . . . . . . . . . . . 7,191 6,323–8,059 7,747 0.93 

Birth order 

First. . . . . . . . . . . . . . . . . . . . . . . . . . 8,046 7,353–8,740 8,262 0.97 

Second . . . . . . . . . . . . . . . . . . . . . . . 6,733 6,143–7,324 6,465 1.04 

Third or higher . . . . . . . . . . . . . . . . . 5,404 4,668–6,139 5,752 0.94 

1

Vital records data from the Centers for Disease Control and Prevention WONDER databases are available from:
 

https://wonder.cdc.gov/.
 2

Includes births to persons of other race and origin groups, those with unknown or not stated birth order, and to women under age 


15, not shown separately.
 

NOTES: NSFG is National Survey of Family Growth. The Hispanic origin and race variable is based on the 1977 OMB guidelines 


to allow comparisons with available vital statistics reports. See the Methods section for further information on the “Hispanic origin 


and race” variable used for the majority of this report. Persons born outside the United States (50 states and Washington, D.C.) are 


limited to births occurring after they came to the United States to stay, because data on births occurring outside the United States 


are not available from vital records.
 

SOURCE: NCHS, National Survey of Family Growth, 2011–2015, and CDC WONDER databases.
 
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National Health Statistics Reports  Number 113  July 11, 2018

Acknowledgments 

The National Survey of Family Growth (NSFG) was conducted by the National Center for Health Statistics (NCHS) at the Centers for Disease 

Control and Prevention (CDC) with the support and assistance of several other organizations and individuals. Interviewing and other tasks for the 

2011–2015 survey period were carried out under a contract with the Survey Research Center at the University of Michigan’s Institute for Social 

Research, under a contract with NCHS. The 2011–2015 NSFG was jointly planned and funded by the following U.S. Department of Health and 

Human Services programs and agencies: 

•	 National Center for Health Statistics (CDC) • Division of Reproductive Health (CDC) 

•	 Eunice Kennedy Shriver National Institute of Child Health and • National Center on Birth Defects and Developmental Disabilities 

Human Development (National Institutes of Health) (CDC) 

•	 Office of Population Affairs • Division of Cancer Prevention and Control (CDC) 

•	 Division of HIV/AIDS Prevention (CDC) • Children’s Bureau 

•	 Division of STD Prevention (CDC) • The Office of the Assistant Secretary for Planning and Evaluation 

NCHS gratefully acknowledges the contributions of these programs and agencies and all others who assisted in designing and 

carrying out NSFG. 

This report was prepared in the Division of Vital Statistics (DVS) under the general direction of Delton Atkinson, Director, DVS; Paul Sutton, Acting 

Chief, Reproductive Statistics Branch (RSB); and Anjani Chandra, Team Leader, RSB NSFG Team. The authors are grateful for the valuable 

comments provided by Hanyu Ni, DVS, Associate Director for Science, and Jennifer Madans, NCHS, Associate Director for Science. 

Suggested citation 

Martinez GM, Daniels K, Febo-Vazquez I. 

Fertility of men and women aged 15–44 in 

the United States: National Survey of Family 

Growth, 2011–2015. National Health Statistics 

Reports; no 113. Hyattsville, MD: National 

Center for Health Statistics. 2018. 

Copyright information 

All material appearing in this report is in 

the public domain and may be reproduced 

or copied without permission; citation as to 

source, however, is appreciated. 

National Center for Health Statistics 

Charles J. Rothwell, M.S., M.B.A., Director 

Jennifer H. Madans, Ph.D., Associate Director 

for Science 

Division of Vital Statistics 

Delton Atkinson, M.P.H., M.P.H., P.M.P., 

Director
 

Hanyu Ni, Ph.D., M.P.H., Associate Director for 


Science
 

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DHHS Publication No. 2018–1250 • CS293349