Trophectoderm/ICM biopsy concordance
Using a new non-toxic imaging method, researchers watched living human embryos divide in real time and discovered that chromosome separation errors linked to mosaicism can arise even at the blastocyst stage, showing that mosaicism is a dynamic process rather than one confined to early development.
A 2024 meta-analysis combined the results of 10 studies to show that embryos that are thawed for PGT-A, or rebiopsied after inconclusive results, have lower chances of pregnancy and live birth, with higher miscarriage rates.
A new case report describes the healthy birth of dizygotic twin girls from embryos labeled as aneuploid by PGT-A, highlighting the limitations of embryo testing and the need to reconsider strict discard protocols.
A 2025 study shows that segmental abnormalities detected by PGT-A in the trophectoderm don’t always match the ICM, suggesting that these embryos may still be viable for transfer.
A 2025 opinion article highlights some of the issues with PGT-A, mainly its uncertain benefit, technical flaws, high costs, and the risk of discarding potentially viable embryos.
A 2024 study performed a more sensitive type of PGT-A by analyzing single cells, finding that nearly all blastocysts and fetal tissue contain some level of mosaicism.
Evidence up to 2022 shows that a single PGT-A biopsy is highly concordant (similar) with the rest of the embryo when the embryo is aneuploid or euploid, but not when it’s mosaic or segmental.
