Relationship between pituitary reserve and efficacy of bromocriptine in women with euprolactinemic ovulatory dysfunction.

To evaluate the relationship between pituitary reserve and efficacy of bromocriptine therapy in patients with euprolactinemic ovulatory dysfunction, the responses of prolactin (PRL) to thyrotropin-releasing hormone (TRH) and luteinizing hormone (LH), follicle-stimulating hormone (FSH) to gonadotropin-releasing hormone (GnRH) provocation in 46 anovulatory patients were compared with 15 normally cycling ovulatory women. After provocation, the patients were treated with bromocriptine 2.5 mg twice a day for two weeks from the day of menstruation or withdrawal bleeding. Within 12 weeks, 29 of 46 (63.0%) patients had resumption of ovulatory menstruation, and 11 of them became pregnant. There were a significantly (P < 0.001) exaggerated responses of PRL to TRH in bromocriptine responders compared to controls and nonresponders. Also, LH responses to GnRH were higher in responders than in controls and nonresponders, although there was no significant differences. However, FSH responses to GnRH were significantly (P < 0.005) lower in bromocriptine nonresponders, as compared with the controls and responders. These results demonstrate that pituitary reserve of PRL and gonadotropin may correlate with the efficacy of bromocriptine and aid to predict the outcome of therapy in patients with euprolactinemic ovulatory dysfunction.