Revisiting the clomifene-gonadotropin protocol in IVF with the use of a GnRH antagonist

OBJECTIVE: To assess the ability of GnRH antagonists to prevent LH surges during superovulation for IVF in classical stimulation protocols with clomiphene and gonadotropins. PATIENTS AND METHODS: Fifty-eight patients were treated with clomiphene (100 mg daily for 5 days starting on cycle day 2) and gonadotropins (225 UI HMG on cycle days 5, 7 and 9), with monitoring starting on cycle day 10. Cetrorelix, 0.25 mg, was administered daily when dominant follicle diameter reached 18 mm and/or plasma estradiol levels 800 pg/ml. RESULTS: No premature LH surge was observed during the 48 stimulation cycles completed. The pregnancy rate was 20.8% per punction and 25.6% per transfer, and there was no clinical ovarian hyperstimulation syndrome in these series. CONCLUSIONS: Cetrorelix, 0.25 mg, optimizes the classical stimulation with clomiphene and gonadotropins by preventing LH surges; the so-completed protocol yields acceptable pregnancy rates with lower hormone quantities and reduced risks of ovarian hyperstimulation, and becomes a convenient choice when "softer" treatments for IVF are considered.