Follicular development and oocyte maturation after stimulation with gonadotropins versus leuprolide acetate/gonadotropins during in vitro fertilization.

Follicular development and oocyte maturation were compared in 22 patients stimulated with human menopausal gonadotropins/human chorionic gonadotropin (hCG, group I) and in 52 women also treated with the gonadotropin-releasing hormone agonist (GnRH-a) leuprolide acetate (LA, group II). Suppression of endogenous leutinizing hormone (LH) surges by LA allowed delayed hCG administration, resulting in higher peripheral estradiol levels, more retrieved oocyte cumulus corona complexes, and greater numbers of cryopreserved embryos. Reduction in spontaneous LH surges in the GnRH-a cycles may have allowed time for larger follicular fluid (FF) volume accumulation during all phases of oocyte cumulus corona complex maturation, restoring synchrony between FF volume and oocyte cumulus corona complex maturity.