Objectives:To identify contraction (CT) patterns in human blastocysts using a Time-Lapse incubator and to correlate them with their ploidy status by PGT-A analysis, the time they took to reach blastocyst state, implantation rate and clinical pregnancy rate. Design: Retrospective cohort study. Interventions: From October 2016 through May 2018, 270 patients were evaluated, 912 embryos were cultivated in the Time-Lapse (Embryoscope™, Vitrolife) incubator; 778 of them were tested for aneuploidy using an NGS platform in a reference laboratory. Vitrification was performed according to the result of embryo development and awaiting the NGS result, followed by devitrification and transfer of a single embryo. Blastocyst contractions (CT) were determined using the EmbryoViewer (EmbryoViewer™ drawing tools) in order to obtain area, percentage of contraction and the various types of contractions,...