Estradiol pretreatment in GnRH antagonist protocol for IVF/ICSI treatment

We conducted a systematic review and meta-analysis of all published data to determine the impact of estradiol pretreatment on reproductive outcomes and ovary stimulation characteristics for in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment with gonadotropin-releasing hormone (GnRH) antagonist protocol. MEDLINE, EMBASE, Cochrane Library, Web of Science, and China National Knowledge Infrastructure were searched, and any randomized controlled trials associated with estradiol pretreatment in GnRH antagonist protocol were included. Seven studies (1,236 patients) were included in the present study. The pooled data from the meta-analysis demonstrated no significant difference in ongoing pregnancy rate (odds ratio (OR): 0.92 (95% CI: 0.69-1.21; P = 0.53) and live birth rate OR: 0.98 (95% CI: 0.74-1.30; P = 0.90) between patients with and those without estradiol pretreatment in GnRH antagonist protocol. Duration of gonadotropin exposure, gonadotropin consumption, and the number of cumulus-oocyte complexes were not significantly different between groups. Luteal estradiol pretreatment in IVF/ICSI cycles with GnRH antagonist protocol in normal ovary responding population does not affect the reproductive outcomes. It is an encouraging option to facilitate cycle scheduling in GnRH antagonist protocol, for luteal estradiol pretreatment does not increase the duration of gonadotropin exposure or gonadotropin consumption.