RESUMO
OBJECTIVE: To identify baseline characteristics of couples that are likely to predict conception, clinical pregnancy, and live birth after up to four cycles of ovarian stimulation with IUI in couples with unexplained infertility. DESIGN: Secondary analyses of data from a prospective, randomized, multicenter clinical trial investigating pregnancy, live birth, and multiple pregnancy rates after ovarian stimulation-IUI with clomiphene citrate, letrozole, or gonadotropins. SETTING: Outpatient clinical units. PATIENT(S): Nine-hundred couples with unexplained infertility who participated in the Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation clinical trial. INTERVENTION(S): As part of the clinical trial, treatment was randomized equally to one of three arms and continued for up to four cycles or until pregnancy was achieved. MAIN OUTCOME MEASURE(S): Conception, clinical pregnancy, and live-birth rates. RESULT(S): In a multivariable logistic regression analysis, after adjustment for other covariates, age, waist circumference, income level, duration of infertility, and a history of prior pregnancy loss were significantly associated with at least one pregnancy outcome. Other baseline demographic and lifestyle characteristics including smoking, alcohol use, and serum levels of antimüllerian hormone were not significantly associated with pregnancy outcomes. CONCLUSION(S): While age and duration of infertility were significant predictors of all pregnancy outcomes, many other baseline characteristics were not. The identification of level of income as a significant predictor of outcomes independent of race and education may reflect differences in the underlying etiologies of unexplained infertility or could reveal disparities in access to fertility and/or obstetrical care. CLINICAL TRIAL REGISTRATION: NCT01044862.