Is a GnRH antagonist protocol better in PCOS patients? A meta-analysis of RCTs

To review published randomized controlled trials (RCTs) evaluating the outcomes of in vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) utilization of gonadotropin-releasing hormone (GnRH) antagonists for ovarian stimulation in polycystic ovarian syndrome (PCOS) patients compared with classic luteal long agonist protocols. A meta-analysis of prospective randomized trials published in English between 2002 and 2013. Nine RCTs examining PCOS patients undergoing IVF/ICSI including 588 women who underwent long agonist protocols and 554 women who underwent GnRH antagonist protocols. Clinical pregnancy rate (CPR), ongoing pregnancy rate (OPR) and ovarian hyperstimulation syndrome (OHSS) rate. Nine RCTs were included in this analysis. The CPR-per-embryo transferred was similar in the two groups (relative risk (RR): 0.97, 95% confidence interval (CI): 0.85-1.10). Non-significant estimates comparing the two protocols were found for age, BMI, total dose of gonadotropin administered, number of days of stimulation and number of oocytes retrieved. After meta-analysis of 4 of the RCTs, it was concluded that a GnRH antagonist protocol is better than an agonist long protocol to reduce the rate of severe OHSS (odds ratio (OR): 1.56, 95% CI: 0.29-8.51). With respect to CPR, a GnRH antagonist protocol is similar to a GnRH agonist long protocol. However, for severe OHSS, a GnRH antagonist protocol is significantly better in PCOS patients.