The clinical benefit of Blasotcyst transfer (BT) in IVF-ET is still controversial. Recent study elucidated the benefit of BT to reduce ectopic pregnancy in assisted reproduction. Retrospective analysis of pregnancies with BT showed lower ectopic pregnancy rate compared to the cleaved stage transfer, especially among patients with tubal factor. There could be few chance of embryo migration into the tube after BT because of a limited period from transfer to implantation, and a reduced frequency of uterine contraction at the time of transfer.