Comparison between flare up and down regulation effects of luteinizing hormone-releasing hormone agonists in an in vitro fertilization program.

Luteinizing hormone-releasing hormone (LH-RH) agonists are being increasingly used in ovulation stimulation protocols in IVF programs. The results of two methods of utilization of LH-RH agonists are compared. In the long protocol, gonadotropin stimulation was commenced only after a preliminary period of pituitary desensitization with LH-RH agonist. In the short protocol, exogenous gonadotropins were administered shortly after the start of LH-RH agonist therapy, benefiting from the gonadotropin flare up effect. One hundred eighty-six patients were equally divided between the two treatments. There was no difference in the ovarian response on the day of human chorionic gonadotropin (hCG) or the number of mature oocytes recovered. The cleavage rate of mature oocytes was higher in the short protocol (70% versus 56% P less than 0.01). The ongoing pregnancy rate per treatment cycle was similar in both groups (18% in the long protocol and 16% in the short protocol). Analysis of the luteal phases revealed a trend for higher progesterone values in the long protocol although this was only significant on the 2nd day following oocyte retrieval. As the clinical results were similar, other factors should be taken into account when deciding therapy. These include patient convenience, cost, and side effects. Other schedules of ovulation stimulation with LH-RH agonists are discussed.