[Suppression of endogenous LH increase in ovarian stimulation with the GnRH antagonist Cetrorelix]

Surges of LH in serum, which result in luteinization, but occur prematurely with respect to the diameter of the leading follicle, frustrate attemps to induce multiple follicular maturation for in-vitro fertilisation in a number of women. We examined the possibility of blocking premature LH-surges by the administration of Cetrorelix, a potent antagonist of gonadotrophin releasing hormone. Twenty patients, who had repeatedly shown premature LH surges, were treated with human menopausal gonadotrophins from the 2nd day onwards. From the 7th day until the induction of ovulation by HCG, the GNRH-antagonist Cetrorelix was given daily. HCG was injected when the dominant follicle had reached the diameter of at least 18 mm and oestradiol levels were above 300 pg for each follicle and more than 15 mm. Oocyte collection was performed 36 hours later by transvaginal ultrasound puncture, followed by IVF and embryo transfer. The hormone profiles of these patients and the results of in-vitro fertilisation and embryo transfer are discussed. It could be demonstrated in this study, that combined treatment with gonadotrophins and the GNRH-antagonist seems to be a promising method for ovarian stimulation in patients, who frequently exhibit premature LH discharges and therefore fail to complete treatment.