The use of GnRH analogs for induction of the preovulatory gonadotropin surge in assisted reproduction and prevention of the ovarian hyperstimulation syndrome

Abstract
Ovarian hyperstimulation syndrome (OHSS) remains a potential severe complication of the use of gonadotropin therapy in ovulation induction and assisted reproduction technologies. In 1988, we reported preliminary results which demonstrated the ability of gonadotropin-releasing hormone analogs (GnRH-a) to trigger ovulation, and to prevent subsequent OHSS. In this report, we summarize our experience of 73 treatment cycles involving 44 high responders (i.e. patients with a previous history of severe OHSS, or with high estradiol levels (> 13 200 pmol/l) on the day of triggering the luteinizing hormone (LH) surge). In spite of the high estradiol levels (mean 24 202 pmol/l) and the large number of oocytes (mean 32.4), none of our patients developed severe OHSS. Luteal support with progesterone and estradiol valerate was necessary to maintain adequate serum levels of these hormones. Without such support, a precipitous decline in levels of estradiol and progesterone was observed. We believe that the use of GnRH-a instead of human chorionic gonadotropin (hCG) for the induction of ovulation allows for safe ovarian stimulation without exposing the patient to the risk of OHSS.