THE EFFECT OF THE DURATION OF GNRH-AGONIST DOWN-REGULATION BEFORE OVARIAN STIMULATION ON THE BIOLOGICAL AND CLINICAL OUTCOME AFTER INTRACYTOPLASMIC SPERM INJECTION

The object of this study was to compare the biological outcome (oocyte maturity, fertilization, cleavage) and the clinical outcome after a ' long' (15-24 days) and a 'long-long' (25-40 days) protocol of GnRH-ago nist administration for intracytoplasmic sperm injection. Group A cons isted of 51 patients with a 15-24-day down regulation period and Group B consisted of 35 patients with a 25-40-day down regulation period, a ll of which entered ICSI due to severe male factor infertility. Durati on and amount of gonadotropin stimulation, serum E-2 on the day of hCG administration, number of oocytes retrieved, oocyte maturity, fertili zation rate, cleavage rate and pregnancy outcome were comparable for t he two groups of patients. Therefore, a flexible period of pituitary d esensitization can be employed, allowing us to simplify planning for p atients and for the medical staff without affecting the outcome of the trial. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.