ABSTRACT
The cornerstone of successful assisted reproductive technology (ART) has been the ability to replace several selected preembryos from a larger cohort obtained following recruitment, harvest and fertilization of multiple oocytes. Thus, although the first successful human in vitro fertilization (IVF) pregnancy followed the retrieval of a single oocyte in a spontaneous menstrual cycle1, current standard practice in ART programs worldwide entails the use of controlled ovarian hyperstimulation in order to maximize pregnancy rates. This strategy, while maximizing pregnancy rates, has also been associated with the inherent increased risks of multiple pregnancies. A wide variety of ovulation-inducing agents have been employed in the practice of ART, including clomiphene citrate, human menopausal gonadotropins (hMG), and recombinant gonadotropin preparations, with and without the adjunctive use of gonadotropin releasing hormone (GnRH) agonists and antagonists. Currently, the dominant approach to ovulation induction for IVF combines exogenous gonadotropins (hMG, Puriffied follicle stimulating hormone (FSH) and recombinant FSH) with GnRH agonists.
