Ferreux L, et al. - Researchers here aimed to evaluated the live birth rate (LBR) after frozen–thawed Day 5 (D5) and Day 6 (D6) blastocyst transfers. They observed significantly lower LBR following frozen–thawed blastocyst transfer with D6 than with D5 blastocyst regardless of embryo quality. These observations could affect cryopreservation procedures as they suggested that the use of D5-expanded blastocysts for thawed blastocyst transfer (TBT) could be preferred in order to shorten the time of conceiving.