Live birth and other reproductive outcomes of mosaic and euploid embryos: a systematic review and meta-analysis.

Advances in preimplantation genetic testing for aneuploidy (PGT-A) have improved embryo selection in assisted reproductive technologies (ART). However, the clinical significance of mosaic embryos remains uncertain. This systematic review and meta-analysis evaluates reproductive outcomes following mosaic embryo transfer compared to euploid embryos. Live birth rate was the primary outcome, while secondary outcomes included biochemical pregnancy, biochemical pregnancy loss, miscarriage, clinical pregnancy, ongoing pregnancy, and neonatal outcomes. Our findings indicate that mosaic embryos have significantly lower implantation and live birth rates than euploid embryos, reinforcing the superior reproductive potential of euploid embryos. However, once implantation occurs, biochemical pregnancy loss and miscarriage rates were comparable between groups, suggesting that implantation is the primary limiting factor in mosaic embryo viability. The type and extent of mosaicism may further influence reproductive outcomes, with segmental mosaicism showing better prognoses than whole-chromosome mosaicism. Additionally, a trend toward lower birth weight in mosaic embryos was observed, though neonatal health outcomes remained as favorable as euploid embryos. The heterogeneity in diagnostic and reporting criteria highlights the need for standardized classification of mosaicism to enhance prognostic accuracy. Further research is required to refine embryo selection strategies and improve clinical decision-making in ART.