EVALUATION OF 2 GONADOTROPIN-RELEASING-HORMONE (GNRH) ANALOGS (LEUPROLIDE AND BUSERELIN) IN SHORT AND LONG PROTOCOLS FOR ASSISTED REPRODUCTION TECHNIQUES

Purpose: The administration of two GnRH analogues (buserelin and leupr olide acetate) in long and short protocols was evaluated prospectively . In the long protocol, the analogues were given from day 1 of the cyc le for at least 14 days and then hMG administration was started, while in the short protocol the analogues were initiated from cycle day 1, adding hMG from day 3. The patients were divided into four groups acco rding to the protocol used: Group I, buserelin-long; Group II, buserel in-short; Group III, leuprolide-long; and Group IV, leuprolide-short. Serum E2 levels on the day of hCG injection and the number of follicle s observed, oocytes retrieved, and embryos obtained, as well as implan tation rates, were significantly higher (P < 0.001) in the long protoc ols than in the short ones. Results: Pregnancy rates were similar in a ll groups, although a trend for better results was observed in buserel in-long compared to buserelin-short. There were no differences in the results achieved with buserelin or leuprolide. Conclusion: The adminis tration of GnRH analogues (buserelin and leuprolide acetate) in long p rotocols induced a more intense ovarian response and was associated wi th significantly higher implantation rates and also a trend for higher pregnancy rates, although this difference was not statistically signi ficant.