Wei D, et al. - In this multicentre, non-blinded, randomised controlled trial, researchers ascertained if elective frozen single blastocyst transfer improved singleton livebirth rate vs fresh single blastocyst transfer. This trial was conducted in 21 Chinese academic fertility centres. From August 1, 2016, to June 3, 2017, 1650 women with regular menstrual cycles undergoing their first cycle of in-vitro fertilisation were recruited. Eligible women were either allocated fresh or frozen single blastocyst transfers randomly. In ovulatory women with good prognosis, frozen single blastocyst transfer resulted in a higher singleton live birth rate than fresh single blastocyst transfer. Further studies are warranted by the increased risk of pre-eclampsia after frozen blastocyst transfer.