A short review of ovarian stimulation in assisted reproductive techniques

Ovarian stimulation during assisted human reproduction is currently a standard procedure in assisted reproductive techniques (ART). Its objective is to stimulate the growth of several follicles by injections of FSH-containing compounds, most recently recombinant FSH (rFSH). An injection of human chorionic gonadotrophin (HCG), or a luteinizing hormone-releasing hormone agonist to discharge pituitary LH is then given to invoke follicle and oocyte maturation. Various other medications are also used in addition to specific drugs such as human menopausal gonadotrophin, rFSH, HCG and rLH. Non-specific drugs include clomiphene citrate, other anti-oestrogens, bromoergocryptine, and gonadotrophin-releasing hormone (GnRH) agonists and antagonists. Numerous protocols have been utilized with these agents, the most common being clomiphene citrate and various regimens of gonadotrophins, including step-up, step-down and continuous. The regimens are used with or without GnRH agonists, and with or without GnRH antagonists. In this brief review, the advantages and disadvantages of each protocol are presented.