COMPARISON OF HCG VERSUS GNRH ANALOG FOR RELEASING OOCYTES FOLLOWING ULTRA LOW-DOSE GONADOTROPIN STIMULATION

Previous data have suggested there is a higher incidence of luteinized unruptured follicle (LUF) syndrome (defined as failure to release any oocyte as determined by sonography) in gonadotropin-treated patients following human chorionic gonadotropin (hCG) versus the gonadotropin r eleasing hormone agonist (GnRH-a) leuprolide acetate. The present stud y was designed to determine if an ultra low-dose gonadotropin regimen, designed not to raise the serum estradiol level much above normal for non-stimulated cycles, might result in a decrease in LUF following hC G treatment, and even reduce the rate to that seen following leuprolid e acetate. The hypothesis tested was that the higher estradiol levels might suppress the pre-ovulatory follicle stimulating hormone (FSH) su rge which, in turn, would inhibit plasmin production, thus preventing detachment of the oocyte from the follicle. The data did show a reduce d rate of LUF incidence with either hCG or leuprolide acetate in ultra low-dose human menopausal gonadotropin- (hMG-) treated patients compa red to data from previous studies with conventional hMG/hCG therapy. P regnancy rates were also similar following h CG or leuprolide acetate for release in low-dose hMG-treated patients. Preliminary data show th at leuprolide acetate is superior to hCG for causing oocyte release wh en stimulation is with low-dose purified FSH, and possibly also that l ow-dose hMG is superior to low-dose purified FSH for producing superio r pregnancy rates.