Gonadotropin suppression with oral contraceptives before in vitro fertilization.

One hundred eighty-one stimulation cycles in which gonadotropin suppression with oral contraceptives (OCs) preceded induction of follicle stimulation (study group) and 113 stimulation cycles without pituitary suppression (control group) were compared. The mean length of ovarian suppression was 35.3 +/- 0.9 days. No spontaneous luteinizing hormone (LH) surges occurred when the use of OC preceded ovarian hyperstimulation, whereas in the control group the incidence of LH surges was 19.5%. The mean amount of human menopausal gonadotropin required was significantly lower in the study group than in the control group (8.9 +/- 0.4 and 10.9 +/- 0.4 ampules, respectively). Significantly more follicles greater than or equal to 1.5 cm in diameter were seen on the day before oocyte retrieval and significantly more oocytes were retrieved per attempt in the group with OC pretreatment. Our data clearly demonstrate that OCs are useful in vitro fertilization stimulation protocols to facilitate scheduling of cycles and to prevent spontaneous LH surges.