OBJECTIVE: To evaluate the effect of supernumerary preovulatory follicular reduction as an approach to avoid multiple pregnancies in ovulation induction or superovulation cycles. DESIGN: Retrospective study. SETTING: Tertiary referral center. PATIENT(S): In 26 cycles, 24 patients underwent ovulation induction or superovulation with either clomiphene citrate or hMG. INTERVENTION(S): Selective follicle aspiration was performed before hCG administration. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate and numbers of multiple pregnancies. RESULT(S): A mean number of 4.5 follicles with a diameter > or =15 mm and a mean number of 4.5 follicles with a diameter or =15 mm and a mean number of 1.8 follicles with a diameter