The impact of infertility on family size in the United States: data from the national survey of family growth

Abstract

OBJECTIVE: Investigators have postulated that family size may be influenced by biologic fertility potential in addition to sociodemographic factors. The aim of the current study is to determine if a diagnosis of infertility is associated with family size in the United States. DESIGN: Cross-sectional, population-based survey. MATERIALS AND METHODS: We analyzed data from the male and female sample of the 2002 National Survey of Family Growth using multivariable logistic regression models to determine the relationship between infertility and family size while adjusting for sociodemographic and reproductive characteristics. Given that many childless respondents had not actively pursued procreation and reproductive intent can be difficult to ascertain, only survey respondents with at least one child were included in the present analysis. RESULTS: 4,409 women and 1,739 men met inclusion criteria, of whom 10.2% and 9.7% were infertile, respectively. Men and women who sought reproductive assistance had fewer offspring compared to respondents who did not utilize infertility services (p<0.05). Females who sought reproductive assistance had a 34% reduced odds of having an additional child compared to women who did not seek reproductive assistance. For each additional 6 months it took a woman to conceive her first child, the odds of having a larger family fell by 9% and the odds of having a second child were reduced by 11%. Men who reported difficulty fathering a child had a 66% lower odds of having more than one child compared to men who denied impaired fertility. A diagnosis of male infertility reduced the odds of having a larger family more than a diagnosis of female infertility. CONCLUSION: A diagnosis of infertility, especially male factor, is associated with reduced odds of having a larger family, implicating a biologic role in the determination of family size in the United States.