Blastomere number (BN) at time of start of compaction (tSC) for Day 3 embryos correlates with clinical pregnancy rate (CPR)

Background and Aim: The aim of the study was to examine any correlation between the BN at tSC for Day 3 (D3) embryos and clinical outcome. The study of Le Cruguelet et al (2013), has shown that D3 compacted embryos are correlated with a significantly higher pregnancy and implantation rate, but tSC was not considered. According to guidelines published by Alpha Scientists in Reproductive Medicine and ESHRE Special Interest Group of Embryology (2011), embryos should ideally reach 8 cells by 68±1hr.