SCHEDULED ADMINISTRATION OF A GONADOTROPIN-RELEASING-HORMONE ANTAGONIST (CETRORELIX) ON DAY-8 OF IN-VITRO FERTILIZATION CYCLES - A PILOT-STUDY

To assess in a pilot study the ability of a single injection of a GnRH antagonist (Cetrorelix) to prevent premature luteinizing hormone (LH) surges in an in-vitro fertilization (IVF) embryo transfer programme w hen administered on a fixed day in the late follicular phase, ovarian stimulation was carried out in 11 women with two ampoules of human men opausal gonadotrophin per day beginning on day 2 of the menstrual cycl e, A 3 mg dose of Cetrorelix was administered on day 8 of the stimulat ion cycle, A second injection was administered 72 h later if ovulation was not triggered in the meantime, We did not observe a premature LH surge in any of the cycles studied, The injection of 3 mg Cetrorelix w as capable of preventing LH surge in all the patients studied, introdu cing a very simple treatment protocol, Among the patients who received two injections (n = 3), the day of the first administration was delay ed in two subjects due to slow follicular maturation kinetics. Out of 11 patients, 10 had an embryo transfer. Four clinical pregnancies were obtained (40% per embryo transfer), of which 3 are ongoing (30% per e mbryo transfer), A simple administration protocol for a new GnRH antag onist (Cetrorelix) was able to prevent LH surges in the 11 patients st udied.