Kinetic characteristics of mosaic embryos observed by time-lapse and their post-implantation outcomes: A single-center retrospective cohort study
Year: 2026
Type: article
Study design: Observational Study
Abstract: 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<0.05). No full-term live births were recorded among the embryos with high-level mosaicism for trisomy and segmental aneuploidy, although three live births were observed in high-level mosaic embryos with monosomy. Furthermore, time to blastocyst development was longer in mosaic embryos than in euploid embryos. However, when analyzed according to mosaic level, the developmental kinetics were not sufficiently distinctive to enable reliable non-invasive prediction of mosaic status. Conclusion: This study suggests that ranking embryos by the level and type of mosaicism can help maximize post-implantation outcomes. Live birth rates varied according to the type of mosaicism.
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7130506809