Embryos from IVF cycles are commonly transferred at either the early cleavage stage (day 2 to 3) or blastocyst stage (day 5 to 6).  In this study, we showed that live birth rate is higher when embryo transfer is performed on blastocyst stage. However, as cumulative live birth rate was not evaluated by several of the included randomized controlled trials, we should be cautious with our recommendations.