Suppression of the endogenous luteinizing hormone surge by the gonadotrophin-releasing hormone antagonist Cetrorelix during ovarian stimulation

Surges of luteinizing hormone (LH) that result In luteinizationbut occur prematurely with respect to the diameter of the leadingfolilde, prevent attempts to induce multiple follicular maturationfor in-vitro fertilization (IVF) in a significant number ofwomen. We examined the possibility of blocking premature LIIsurges by the administration of Cetrorelix, a potent antagonistof gonadotrophin-releasing hormone (GnRH), in a study Including20 patients, some of whom had previously shown premature LHsurges. All patients were treated with human menopausal gonadotrophins(HMG) starting on day 2. From day 7 until the induction of ovulationby human chorionic gonadotrophin (HCG) the GnRII antagon Cetrorelixwas given daily. HCG was injected when the dominant fofficlehad reached a diameter of >18 mm and oestradlol concentrationwas >300 pg/ml for each follicle having a diameter of >15mm. Oocyte collection was performed 36 h later by transvaginalultrasound puncture, followed by IVF and embryo transfer. Thehormone profiles of these patients and the results of IVF andembryo transfer are comparable to those treated with GnRH agonistsand HMG. However, less time and especially less HMG Is neededin comparison to patients stimulated with a long agonist protocol.Hence, treatment with Cetrorelix proved to be much more comfortablefor the patient. In this study we showed that combined treatmentwith gonadotrophins and the GnRH antagonist Cetrorelix is apromising method for ovarian stimulation in patients who frequentlyexhibit premature LH surges and therefore fall to complete treatment.