Oral contraceptive pill pretreatment in ovarian stimulation with GnRH antagonists for IVF: a systematic review and meta-analysis

Objective: To assess the impact of oral contraceptive pill (OCP) pretreatment in ovarian stimulation for in vitro fertilization (IVF) using gonadotropin releasing hormone (GnRH) antagonists. Design: Systematic review and meta-analysis of randomized controlled trials (RTC). Setting: University IVF center. Patient(s): Infertile patients (n = 847), treated in four trials. Intervention(s): Systematic literature search (MEDLINE, EMBASE, CENTRAL COCHRANE, conference proceedings, reference lists) for randomized trials on OCP treatment before stimulation with gonadotropins and GnRH antagonist for IVF. Meta-analysis of data yielding pooled odds ratios (OR) or weighted differences of the means (WMD) and 95% confidence intervals (CI). Main Outcome Measure(s): Ongoing pregnancy rate per randomized woman. Result(s): Ongoing pregnancy rate per randomized woman was not found to be significantly different between patients with and those without OCP pretreatment (OR: 0.74, 95% CI: 0.53 to 1.03). Duration of gonadotropin stimulation (WMD: +1.41 days, 95% CI: +1.13 to +1.68) and gonadotropin consumption (WMD: +542 IU, 95% CI: +127 to +956) were significantly increased after OCP pretreatment. No significant differences were observed regarding the number of cumulus-oocyte complexes (COCs) and the fertilization rates. Conclusion(s): A significant difference in ongoing pregnancy rates between patients who received OCP pretreatment and those who did not is currently not present, although further studies are necessary for more solid conclusions on pregnancy likelihood to be drawn.