Objective: To estimate the prevalence of infertility using a current duration approach for comparison with a traditional constructed measure.
Design: Cross-sectional survey.
Setting: Not applicable.
Patient(s): A nationally representative sample of females aged 15-44 years.
Main outcome measure(s): Infertility prevalence estimated by two approaches:  a constructed measure derived from questions on sexual activity, contraception, relationship status, and pregnancy, and  a measure based on estimated time to pregnancy 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.
Result(s): Infertility prevalence was approximately twofold higher using the current duration approach (15.5%; 95% confidence interval 8.6%-27.5%) vs. the constructed measure (7.0%; 95% confidence interval 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, whereas opposing patterns were seen for racial/ethnic identification and poverty status.
Conclusion(s): Infertility prevalence based on a current duration approach was consistent with other US prospective cohort studies with preconception enrollment. These findings underscore the importance of definition and methodologic approach for estimating the prevalence of infertility.
Published by Elsevier Inc.