SUPPRESSION OF THE ENDOGENOUS LUTEINIZING-HORMONE SURGE BY THE GONADOTROPIN-RELEASING-HORMONE ANTAGONIST CETRORELIX DURING OVARIAN STIMULATION

Surges of luteinizing hormone (LH) that result in luteinization but oc cur prematurely, with respect to the diameter of the leading follicle, prevent attempts to induce multiple follicular maturation for in-vitr o fertilization (IVF) in a significant number of women. We examined th e possibility of blocking premature LH surges by the administration of Cetrorelix, a potent antagonist of gonadotrophin-releasing hormone (G nRH), in a study including 20 patients, some of whom had previously sh own premature LH surges. All patients were treated with human menopaus al gonadotrophins (HMG) starting on day 2. From day 7 until the induct ion of ovulation by human chorionic gonadotrophin (HCG) the GnRH antag onist Cetrorelix was given daily. HCG was injected when the dominant f ollicle had reached a diameter of greater than or equal to 18 mm and o estradiol concentration was > 300 pg/ml for each follicle having a dia meter of > 15 mm. Oocyte collection was performed 36 h later by transv aginal ultrasound puncture, followed by IVF and embryo transfer. The h ormone profiles of these patients and the results of IVF and embryo tr ansfer are comparable to those treated with GnRH agonists and HMG. How ever, less time and especially less HMG is needed in comparison to pat ients stimulated with a long agonist protocol. Hence, treatment with C etrorelix proved to be much more comfortable for the patient. In this study we showed that combined treatment with gonadotrophins and the Gn RH antagonist Cetrorelix is a promising method for ovarian stimulation in patients who frequently exhibit premature LH surges and therefore fail to complete treatment.