Is blastulation time frame (D5/6) and origin of the embryo (fresh/frozen) correlated with early embryo development assay (eeva) and reproductive outcome?

Abstract

Introduction: Blastocyst transfers improve reproductive outcomes (better synchrony with endometrium and embryo selection). Berrenetxea et al. (2005) compared implantation and pregnancy rates of blastocysts on day 5–6 observing better results in patients undergoing day 5 transfers. However, Shaphiro et al. (2008) showed contradictory results.