EndocrinologyHormonal profile during the follicular phase in cycles stimulated with a combination of human menopausal gonadotrophin and gonadotrophin-releasing hormone antagonist (Cetrorelix)

A third-generation gonadotrophin-releasing hormone antagonist(Cetrorelix) was used during ovarian stimulation in 32 patientsundergoing assisted reproduction, in order to prevent the prematureluteinizing hormone (LH) surge. In all patients, ovarian stimulationwas carried out with two or three ampoules of human menopausalgonadotrophin (HMG), starting on day 2 of the menstrual cycle.In addition, 0.5 mg of Cetrorelix was administered daily fromday 6 of HMG treatment until the day of ovulation inductionby human chorionic gonadotrophin (HCG). A significant drop inplasma LH concentration was observed within a few hours of thefirst administration of Cetrorelix (P<0.005). Moreover, noLH surge was detected at any point in the treatment period inany of the 32 patients. A mean oestradiol concentration of 2122±935ng/1 was observed on the day of the HCG administration, indicatingnormal folliculogenesis. Like LH, progesterone concentrationalso dropped within a few hours of the first administrationof Cetrorelix (P< 0.005). A 0.5 mg daily dose of Cetrorelixprevented a premature LH surge in all the 32 patients treated.