P721: CGG repeat length and AGG interruptions in FMR1: Association with expansion risk in a reproductive carrier screening population

Results: Our meta-analysis included data from three studies, encompassing a total of 5,161 embryos, of which 745 were mosaic and 4,416 euploid.Treatment with mosaic embryos was not associated with statistically significant differences in the risk of congenital anomalies (OR 1.06; 95% CI 0.59-1.89;p = 0.5479; I 2 = 0%), gestational diabetes (OR 0.94; 95% CI 0.69-1.29;p = 0.9367; I 2 = 0%), or gestational hypertension (OR 0.94; 95% CI 0.65-1.35;p = 0.6992; I 2 = 0%).These results indicate that mosaic and euploid embryos achieve comparable outcomes, supporting the safety of implanting mosaic embryos.Conclusion: Mosaic embryo transfer is not associated with increased risks of congenital anomalies, gestational diabetes, or gestational hypertension compared with euploid embryo transfer.These findings indicate that mosaic and euploid embryos yield comparable obstetric and perinatal outcomes, supporting the clinical safety and viability of mosaic embryo transfer in appropriately selected cases.Further large-scale prospective studies are warranted to refine patient selection and optimize clinical decision-making.