A Cochrane review included 14 studies with a total of 2612 subjects. Eleven trials involving 2396 women used a GnRH agonist. There was no evidence of a statistical difference in live birth rate reported in two trials (OR 1.51, 95% CI 0.79 to 2.87). There was no evidence of a statistical difference in clinical pregnancy rates reported in seven trials OR 1.15, 95% CI 0.91 to 1.45. There was no evidence of a statistical difference or in ongoing pregnancy rates seven trials OR 1.22, 95% CI 0.95 to 1.56. Three trials used a GnRH antagonist. No data on live birth rates was available. There was no evidence of a statistical difference in clinical pregnancy rates (one trial: OR 0.79, 95% CI 0.26 to 2.43) or in ongoing pregnancy rates (two trials: OR 0.83, 95% CI 0.39 to 1.80) comparing both groups. The pooled pregnancy estimates of trials including only poor responders showed significant increase in pregnancy rate, in favour of co-administrating rLH (three trials: OR 1.85, 95% CI 1.10 to 3.11).