Tazegül, AybikeGörkemli, HüseyinÖzdemir, SunaAktan, Tahsin Murad2020-03-262020-03-2620080932-00671432-0711https://dx.doi.org/10.1007/s00404-008-0620-9https://hdl.handle.net/20.500.12395/22270Objective To investigate the efficacy of gonadotropin releasing hormone antagonist (GnRH) in poor responders undergoing in vitro fertilization. Study design Ninety-six patients with poor ovarian response in previous treatment cycles were prospectively randomized into two groups. Forty-four patients were stimulated with GnRH antagonist multidose protocol and 45 patients received a standard long agonist protocol. Ovarian response was evaluated by transvaginal ultrasound and hormonal parameters. Cycle characteristics and treatment outcomes were statistically compared between groups. Results There was significantly reduced duration of stimulation and consumption of gonadotrophins in the antagonist group when compared to the agonist group. The estradiol concentrations on the day of human chorionic gonadotropin (hCG) injection, the number of oocytes retrieved, and the number of embryos transferred were similar for both groups. In the antagonist group, eight (18.1%) ongoing pregnancies were achieved and in the agonist group, ten (22.2%) clinical pregnancies were achieved but the difference was not statistically significant. Conclusions The present study was not powered to detect clinically relevant differences between two protocols in outcomes such as pregnancy rate, with confidence.en10.1007/s00404-008-0620-9info:eu-repo/semantics/closedAccessGnRH antagonistGnRH long agonistin vitro fertilizationpoor responderArticle278546747218335226Q2WOS:000259040400012Q4