A nonconcurrent prospective analysis is made in an attempt to evaluate the gestational fate of clomiphene-related conceptions (study series, n=86). This latter series was contrasted with a series of pregnancies following bilateral ovarian wedge resection (BOWR) (n=51) in a comparative analysis of gestational outcome event rates. Post-therapy follow-up was available for varying time spans of up to 15 years. A 12.8% twinning rate constituted the single most important complication of clomiphene therapy, resulting in measurable increments in perinatal morbidity and mortality rates. The observation of a 26.5% spontaneous abortion rate would seem to suggest that clomiphene-related conceptions are at little or no more risk for spontaneous abortion than would have been expected from the infertile population under discussion. A 3.1% incidence of post-clomiphene birth defects was not increased as compared with commonly quoted rates for the population at large. The corresponding incidence rates of twinning, spontaneous abortion, and birth defects for the BOWR series were 0%, 21.6% and 0%, respectively.