What is the optimal GnRH antagonist protocol for ovarian stimulation during ART treatment? A systematic review and network meta-analysis.

Available evidence, mostly of low quality and certainty, suggests that different antagonist protocols should not be considered as equivalent for clinical decision-making. More trials are required to assess the comparative effectiveness of ganirelix versus cetrorelix, the effect of different pretreatment interventions (e.g. progestins or oestradiol) or the effect of different criteria for initiation of the antagonist in the flexible protocol. Furthermore, more studies are required examining the optimal GnRH antagonist protocol in women with high or low response to ovarian stimulation.