Meta-analysis of GnRH-antagonists versus GnRH-agonists in poor responder protocols.

Based on the present meta-analysis, agonist protocols could be suggested as a first choice approach, in terms of effectiveness. Due to the high studies' heterogeneity, results should be considered with caution. Accordingly, larger cohort studies and meta-analyses like the present one will enhance the robustness of the emerging results to identify the ideal protocol for poor responders.