Embryo selection or uterine environment: Which plays the greater role in blastocyst transfer cycles?

摘要

Aim: Blastocyst stage embryo transfer (BET) leads to higher pregnancy rates when compared to cleavage stage transfer. Better embryo selection and a more physiologic stage of transfer are possible explanations. We assessed the significance of embryo selection in achieving an improved outcome. Methods: Retrospective analysis of all BETs from our 2007 IVF database was performed. The BET cycles were grouped based on the number of top-quality cleavage stage embryos (3). A cut-off of 3 top-quality cleavage embryos, n = 219). The number of follicles >14 mm and the number of eggs/mature eggs were higher in the group with >3 good quality day 3 embryos. Slightly more embryos were transferred in the