Healthy live births achieved from embryos diagnosed as non-mosaic segmental aneuploid.

Purpose: To investigate pregnancy outcomes resulting from transfer of embryos with non-mosaic (NM) segmental aneuploid (SA) results following preimplantation genetic testing for aneuploidy (PGT-A).

Methods: All patients who underwent frozen embryo transfer (FET) of at least one embryo with a NM-SA between March 2021 and April 2024 were retrospectively reviewed. Primary outcomes included live birth rate (LBR) and results of prenatal diagnosis. Embryos with NM-SA results were also compared to those with NM whole chromosome aneuploid (WCA) and mosaic SA results.

Results: Out of 25 NM-SA embryos transferred, the LBR was 24%. Prenatal diagnosis by amniocentesis and/or chorionic villus sampling was performed in 3/6 pregnancies, and results were normal. Embryos with duplications produced more live births compared to those with deletions. NM-SA embryos had a significantly higher ongoing pregnancy (OP)/LBR compared to embryos with NM-WCA results and a significantly lower OP/LBR compared to embryos with mosaic SA results; however, when compared to embryos with high-level SA mosaicism > 40%, the OP/LBR was not significantly different.

Conclusion: Embryos with NM-SAs can result in euploid live births, albeit at reduced rates compared to those with mosaic SAs. These data can be used to aid in patient counseling about PGT-A results and embryo transfer decisions.