Objective To estimate the prevalence of infertility using a current duration approach for comparison with a traditional constructed measure. Design Cross-sectional survey. Setting National Survey of Family Growth, United States, 2002. Participants A nationally-representative sample of females aged 15–44 years. Interventions None Main Outcome Measure(s) Infertility prevalence estimated by two approaches: 1) a constructed measure derived from questions on sexual activity, contraception, relationship status, and pregnancy, and 2) a measure based on estimated time-to-pregnancy (TTP) derived from the respondents’ current duration of pregnancy attempt (i.e., current duration approach). Associations with self-reported descriptive characteristics using weighted logistic regression or parametric survival models for each respective approach. Results Infertility prevalence was approximately twofold higher using the current duration approach (15.5%; 95% CI: 8.6, 27.5) versus the constructed measure (7.0%; 95% CI: 6.2, 7.8). Both methods identified similar patterns of increasing age, lower education, nulliparity, and history of gynecologic disorders as being associated with measures of impaired fecundity, while opposing patterns were seen for racial/ethnic identification and poverty status. Conclusions Infertility prevalence based on a current duration approach was consistent with other U.S. prospective cohort studies with preconception enrollment. These findings underscore the importance of definition and methodologic approach for estimating the prevalence of infertility.

Infertility is a couple based fecundity impairment, though population level research is largely based upon information reported by female partners. Of the few studies focusing on male partners, most focus on the utilization of infertility services rather than efforts to estimate the prevalence and determinants of infertility as reported by male partners. Data from a nationally-representative sample of men aged 15–44 years who participated in the 2002 National Survey of Family Growth (NSFG) were used to estimate the prevalence of infertility and determinants of longer time-to-pregnancy (TTP) using the novel current duration approach. Using backward recurrence time parametric survival methods, we estimated infertility prevalence (TTP > 12 months) and time ratios (TR) associated with TTP as derived from males’ reported current duration of their pregnancy attempt. The estimated prevalence of infertility was 12.0% (95% CI: 7.0, 23.2). Longer TTP was associated with older male age (35–45 vs. 17–24 years) (TR: 2.49; 95% CI: 1.03, 6.03), biological childlessness (TR: 1.53; 95% CI: 1.07, 2.19), and lack of health insurance (TR: 1.73; 95% CI: 1.02, 2.94) after controlling for the differences in couples’ age and other socioeconomic factors. The prevalence of infertility based on male reporting is consistent with estimates of infertility in the United States found in prospective cohort studies and current duration studies based on female reporting. Our findings suggest that males can reliably inform about couple infertility. Interventions and services aimed at reducing couple infertility should include attention to male factors associated with longer TTP identified in this study.

Objective To estimate the prevalence of unintended pregnancies under relaxed assumptions regarding birth control use compared with a traditional constructed measure. Design Cross-sectional survey. Setting Not applicable. Patients Nationally representative sample of U.S. females aged 15–44 years. Intervention(s) None. Main Outcome Measure(s) The prevalence of intended and unintended pregnancies as estimated by 1) a traditional constructed measure from the National Survey of Family Growth (NSFG), and 2) a constructed measure relaxing assumptions regarding birth control use, reasons for non-use, and pregnancy timing. Results The prevalence of unintended pregnancies was 6% higher using the traditional constructed measure as compared to the approach with relaxed assumptions (NSFG: 44%, 95% confidence interval [CI] 41, 46; new construct 38%, 95% CI 36, 41). Using the NSFG approach only 92% of women who stopped birth control to become pregnant and 0% of women who were not using contraceptives at the time of the pregnancy and reported that they did not mind getting pregnant were classified as having intended pregnancies, compared to 100% using the new construct. Conclusion Current measures of pregnancy intention may overestimate rates of unintended pregnancy, with over 340,000 pregnancies in the United States misclassified as unintended using the current approach, corresponding to an estimated savings of $678 million in public health care expenditures. Current constructs make assumptions that may not reflect contemporary reproductive practices and improved measures are needed.