Coello A, et al. – Analysts depict the morphological dynamics of vitrified/warmed blastocysts and aim to identify quantitative morphological factors identified with implantation. The investigation of warmed blastocysts by time–lapse imaging may provide objective quantitative markers for the blastocyst implantation potential. They propose a hierarchical model to classify vitrified/warmed blastocysts according to their implantation probability. The observed correlations and the proposed algorithm ought to be validated in a prospective trial to assess its effectiveness.