Kinetic characteristics of mosaic embryos observed by time-lapse and their post-implantation outcomes: A single-center retrospective cohort study

Objective: The interpretation and evaluation of mosaicism in pre-implantation genetic testing for aneuploidy (PGT-A) are complex, and no consensus or standardized criteria are currently available. We investigated whether mosaicism, as assessed by type or level in PGT-A, is correlated with clinical pregnancy and live birth rates. Methods: This retrospective experimental trial included 207 oocyte retrieval cycles and 124 cycles of single vitrified-warmed blastocyst transfer performed between August 2020 and March 2023 at a single in vitro fertilization center. A total of 124 single vitrified-warmed blastocyst transfer cycles were analyzed for clinical outcomes, stratified by mosaic type and level. We also analyzed the correlations between kinetic characteristics and embryo ploidy. Results: No significant difference in live birth rates was found between the euploid and low-level mosaic groups (52.9% vs. 35.7%). However, live birth rates were significantly lower in the high-level mosaic group than in the euploid group (52.9% vs. 17.6%, p