- The present study compared the effect of gonadotropin therapy alone with a combination of gonadotropins and GnRH agonist on ovarian stimulation in anovulatory women and in spontaneously ovulating patients in an IVF program. Nineteen infertile patients were treated with combined GnRH agonist/gonadotropin therapy for induction of ovulation. Ten women received combined therapy for ovarian stimulation in the framework of an IVF-ET program. Twenty-one additional patients served as controls, receiving gonadotropins but not GnRH agonist for induction of ovulation or ovarian stimulation stimulation before IVF-ET. This study indicates that the GnRH agonists Buserelin, Decapeptyl, and Decapeptyl CR are similarly effective in their ability to down-regulate pituitary-ovarian axis function. The suppressive effect occurred by 14 days in 77% of the patients, and never required more than 28 days. Stimulation of ovarian function, when carried out in the presence of a suppressed pituitary-ovarian axis, required an increased dose of exogenous gonadotropins (26.4 vs. 16.5 ampules). Our data do not support the view that GnRH analogs can aid in the synchronization process of oocyte maturation.