BACKGROUND: The aim of this systematic review and meta-analysis was to evaluate whether the addition of GnRH agonist for luteal support in ICSI/IVF cycles enhances the probability of live birth.METHODS: Systematic literature search (MEDLINE, EMBASE, CENTRAL and RCT registries) was conducted to identify relevant randomized controlled trials published as full manuscripts. Meta-analysis of data yielded pooled risk differences (RDs) and 95% confidence intervals (CIs). A random effects model was applied for pooling the studies.RESULTS: Six relevant RCTs were identified including a total of 2012 patients. The probability of live birth rate (RD: +16%, 95% CI: +10 to +22%) was significantly higher in patients who received GnRH agonist support compared with those who did not. The subgroup analysis according to the type of GnRH analogue used for LH suppression did not change the effect observed (studies in which GnRH agonist was used during ovarian stimulation, RD: +15%, 95% CI: +5 to +23%); (studies in which GnRH antagonist was used during ovarian stimulation, RD: +19%, 95% CI: +11 to +27%).CONCLUSIONS: The best available evidence suggests that GnRH agonist addition during the luteal phase significantly increases the probability of live birth rates.