Blank C, DeCroo I, Weyers B, et al. - Researchers here examined the predictive value of the dynamic morphological development process between cleavage-stage and blastocyst-stage embryos via performing a retrospective study at Ghent University Hospital including a total of 996 first fresh IVF/ICSI cycles resulting in a single embryo transfer on day 5. On day 3 and day 5, they scored embryos as excellent, good, moderate or poor based on Alpha/ESHRE guidelines and Gardner and Schoolcraft scoring-system. On day 5, excellent embryos had the ongoing pregnancy rate (OPR) of 37.4%. Outcomes indicated more predictive value of day-5 embryo scoring for ongoing pregnancy outcome than the same scoring on day 3. The established day 5 variables should initially be employed to select blastocyst-stage embryos. They emphasize considering dynamic evaluation of the embryo quality between day 3 - 5 as a second parameter.