P-555 Improved clinical validity of Preimplantation Genetic Testing for Aneuploidy (PGT-A) using a next-generation sequencing workflow for simultaneous detection of aneuploidy, ploidy and common pathogenic microdeletions

Abstract Study question Can chromosomal abnormalities beyond aneuploidies (i.e., ploidy and microdeletions, MD) be detected on a single trophectoderm (TE) embryo biopsy using a next-generation sequencing (NGS)-based workflow? Summary answer This NGS-based integrated approach allows accurate detection of ploidy status and the most common microdeletions from a single TE-biopsy,expanding PGT-A clinical validity and diagnostic capabilities. What is known already Standard methodologies employed in PGT-A do not determine embryo ploidy status due to the normalization process during copy-number-variation analysis. Transferring embryos with abnormal ploidy variations is expected to result in miscarriage or molar pregnancy. Common pathogenic MD are undetected as they fall below the PGT-A resolution limit (