COMPARISON OF DIFFERENT DOSES OF GONADOTROPIN-RELEASING-HORMONE ANTAGONIST CETRORELIX DURING CONTROLLED OVARIAN HYPERSTIMULATION

Objective: To assess the minimal effective dose of a GnRH antagonist ( Cetrorelix; Asta Medical, Frankfurt, Germany) to prevent premature LH surge in patients undergoing controlled ovarian hyperstimulation (COH) for assisted reproductive technologies. Design: In 69 patients COH wa s carried out with the association of hMG, starting on day 2 of the me nstrual cycle, and a GnRH antagonist (Cetrorelix) was administered fro m day 6 of the hMG treatment (day 7 of the menstrual cycle) every day up to and including the last day of the hMG injection. In 32 and 30 pa tients, 0.5 mg and 0.25 mg of Cetrorelix were administered, respective ly. Seven patients received 0.1 mg of Cetrorelix. Setting: Tertiary re ferral center. Result(s): No premature endogenous LH surge occurred in patients treated with 0.5 and 0.25 mg of Cetrorelix, and serum LH con centrations were maintained constantly low during the entire follicula r phase in both groups. Follicle-stimulating hormone, LH, E-2, and P e xpressed as area under the curve were similar in both groups. A premat ure LH surge (18 mIU/mL; conversion factor to SI unit, 1.00) with a co ncomitant P rise (1.7 mu g/L; conversion factor to SI unit, 3.180) occ urred in one of the seven patients treated with 0.1 mg Cetrorelix; the refore, treatment with this dose was discontinued. Conclusion(s): The minimal effective dose of Cetrorelix able to prevent premature LH surg e in COH cycles is 0.25 mg administered daily. (C) 1997 by American So ciety for Reproductive Medicine.