The effectiveness of gonadotropin-releasing hormone antagonist in poor ovarian responders undergoing in vitro fertilization: a systematic review and meta-analysis

To evaluate the effectiveness of gonadotropin-releasing hormone (GnRH) antagonist in poor ovarian responders undergoing in vitro fertilization (IVF).Systematic review and meta-analysis.Affiliated hospital with a medical university.None.Electronic search.Clinical pregnancy rate, number of oocytes retrieved, cycle cancellation rate.A total of 12 published studies (1,332 cases) were included. Both the stimulation period (mean difference [MD], -0.43; 95% confidence interval [CI], -0.68 to -0.17) and the gonadotropin dosage (MD, -5.41; 95% CI, -7.51 to -3.31) were statistically significantly lower in the GnRH antagonist protocol than in the long GnRH agonist protocol. Both the endometrial thickness (MD -0.45; 95% CI, -0.76 to -0.13) and estrogen (E2) level on the day of hCG administration (MD, -1,299.15; 95% CI, -1,716.34 to -881.95) were statistically significantly lower in the GnRH antagonist protocol than the GnRH agonist protocol. Fewer oocytes were retrieved for the GnRH antagonist protocol than the long GnRH agonist protocol (MD, -0.34; 95% CI, -0.54 to -0.13) or the short GnRH agonist protocol (MD, -0.54; 95% CI, -0.9, 8 to -0.10). The cycle cancellation and clinical pregnancy rates were not statistically significantly different between the two groups.Compared with GnRH agonist protocols, the GnRH antagonist protocol is associated with fewer oocytes retrieved, lower E2 levels, and thinner endometrium whereas the clinical pregnancy and cycle cancellation rates are similar.