Suppression and recovery of gonadotropin and steroid secretion by a gonadotropin-releasing hormone receptor antagonist in healthy women with normal ovulation versus women with polycystic ovary syndrome in the early follicular phase

Objective: To evaluate the effects of the GnRH antagonist cetrorelix on the gonadal axis inpatients with polycystic ovary syndrome (PCOS). Design: Observational clinical study. Setting: Academic research center. Patient(s): Ten patients with PCOS and 10 controls with normal ovulation. Intervention(s): Patients received a daily cetrorelix injection (0.25 mg SC at 9:00 AM) for 6 days, starting from day 3 of the menstrual cycle. Main Outcome Measure(s): Serum gonadotropin, E-2, T, 17-OH-P, and androstenedione plasma levels were evaluated at baseline and at 12 and 24 hours after each daily injection. These hormones were also assayed at days 10, 12, and 14 of the menstrual cycle. Result(s): We observed in patients with PCOS a significantly higher suppression of FSH and LH for the entire length of therapy; LH recovery secretion was significantly higher in the PCOS group. Regarding androgens, we found a greater suppression of T. Androstenedione and 17-OH-P showed a trend toward a higher suppression in PCOS. Conclusion(s): Gonadotropin and androgen suppression by GnRH antagonist is more effective in PCOS than in controls, suggesting a higher sensitivity of GnRH receptors in PCOS to this drug. (Fertil Steril(R) 2009;91: 1857-63. (C) 2009 by American Society for Reproductive Medicine.)