Induction of multiple follicular growth in normally menstruating women with endogenous gonadotropin suppression.

Patients with normal menstrual rhythm and normal luteinizing hormone were treated with exogenous gonadotropins to induce multiple follicular development. This was effected in the absence (34 cycles in 12 patients) or with concurrent suppression of endogenous gonadotropin levels with a gonadotropin-releasing hormone analog (84 cycles in 18 patients). In the absence of the analog, "premature" luteinization occurred in 51% of cycles before the ultrasonic visualization of a follicle with a diameter of 20 mm. In the analog-treated cycles, premature luteinization was almost totally eliminated and progesterone elevations were delayed until after administration of human chorionic gonadotropin. Follicular estrogen production was unaffected by the analog treatment, compared with hypogonadal patients treated with exogenous gonadotropins. The characteristics of follicular development showed that two to three follicles of mature size were induced with this technique, and the capacity for the induction of a larger number of follicles was evident.