Received May 01, 2013
Accepted September 01, 2013

ABSTRACT Objective: to evaluate the results of gonadotropin-releasing hormone agonist (GnRH-ag) and gonadotropin-releasing hormone antagonist (GnRH-ant) using daily dose fixed of rFSH, in Brazilian normoresponder patients undergoing their first in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycle. Methods: a total 50 women were included in this retrospective comparative study. Patients were stimulated with standard 150 IU/day recombinant FSH (follitropin alfa). In group GnRH-ag a daily dose of leuprolide acetate (1mg short protocol) was administered starting on day 1 of the cycle till the day of hCG injection. In GnRH-ant group a daily dose of cetrorelix acetate (0.25 mg) was administered when follicles reached a diameter of ≥14 mm. Recombinant human chorionic gonadotropin (250 μgrhCG) was administered when at least three follicles of 18 mm in diameter were observed. Stimulation characteristics and outcome of both protocols were compared. Results: stimulation days with rFSH (11.0 vs. 9.24;p=0.0091), total doses of rFSH (2094 vs. 1365 IU; p<0.0001), GnRH using days (12.0 vs. 3.6; p<0.0001), and total doses of GnRH (1.2 vs. 0.9 mg; p=0.0001)was shorter in GnRH-antagonist group. The number of follicles (≥ 16 mm) on day rhCG (6.76 vs. 4.64; p=0.04) was higher in GnRH-ag group. There was no difference in the other parameters, nevertheless, the number oocytes retrieved (5.92 vs. 4.16; p=0.06) was higher in GnRH-agonist group, but the fertilization rate (40.1 vs. 54.4%; p=0.29) was higher in GnRH-antagonist group. The rates of chemical and clinical pregnancy were similar in two groups. Conclusion: controlled ovarian stimulation plays a major role in human reproduction and, it is well known that, even in normoresponders patients, the first treatment cycle exposes patients to a risk of either a low or an excessive ovarian response. In this study GnRH-ag and GnRH ant provide comparable results, but antagonist protocol was shorter period of stimulation.