HORMONAL PROFILE DURING THE FOLLICULAR PHASE IN CYCLES STIMULATED WITH A COMBINATION OF HUMAN MENOPAUSAL GONADOTROPIN AND GONADOTROPIN-RELEASING-HORMONE ANTAGONIST (CETRORELIX)

A third-generation gonadotrophin-releasing hormone antagonist agonist (Cetrorelix) was used during ovarian stimulation in 32 patients underg oing assisted reproduction, in order to pl event the premature luteini zing hormone (LB) surge, In ail patients, ovarian stimulation was carr ied out with two or three ampoules of human menopausal gonadotrophin ( HMG), starting on day 2 of the menstrual cycle, In addition, 0.5 mg of Cetrorelix was administered daily from day 6 of HMG treatment until t he day of ovulation induction by human chorionic gonadotrophin (HCG). A significant drop in plasma LH concentration was observed within a fe w hours of the first administration of Cetrorelix (P < 0.005). Moreove r, no LH surge was detected at any point in the treatment period in an y of the 32 patients, A mean oestradiol concentration of 2122 +/- 935 ng/l was observed on the day of the HCG administration, indicating nor mal folliculogenesis, Like LH, progesterone concentration also dropped within a few hours of the first administration of Cetrorelix (P < 0.0 05). A 0.5 mg daily dose of Cetrorelix prevented a premature LH surge in all the 32 patients treated.