Evidence-Based Reporting in Preimplantation Genetic Testing (PGT).

Preimplantation genetic testing (PGT) reports play a decisive role in determining the fate of IVF-generated embryos. The identification of a chromosomal or genetic abnormality that could impact the health of the resulting newborn often leads to embryo disposal or indefinite storage in cryogenic containers. As a growing proportion of IVF cycles include PGT assessment, greater scrutiny is being placed on its clinical validity. Initially developed to detect monogenic disorders (PGT-M) and later expanded to identify full chromosomal aneuploidies, PGT is primarily used to identify embryos unlikely to implant (aneuploid), those that would lead to miscarriage, or those causing chromosomal syndromes or monogenic conditions. Advancements in genetic analysis now allow for the assessment of more complex traits and chromosomal features from a trophectoderm biopsy, including segmental aneuploidies, chromosomal mosaicism, and polygenic conditions. However, as technology pushes the limits of biological resolution, questions arise regarding the accuracy, clinical utility, and representativeness of these findings for the entire embryo. This article reviews the gold standards for validating clinical findings and reporting strategies, aiming to maximize diagnostic utility while minimizing false positives towards appropriately defined reproductive outcomes and phenotypes.