P-742 Universal genome-wide haplotyping-based preimplantation genetic testing: a systematic seven-year experience at a single center

Abstract Study question To record the outcome and clinical benefit of universal genome-wide haplotyping-based preimplantation genetic testing (PGT). Summary answer Universal PGT allows for standardization protocols reduces turnaround time. Apart from accurate diagnosis, it also provides chromosome information, improving embryo selection strategies. What is known already Developments in technologies leveraged implementation that combines haplotyping copy number typing across whole genome. diagnosis any familial monogenic disorder (PGT-M) or structural rearrangement (PGT-SR), concurrent aneuploidy screening (PGT-A) PGT-M/SR cycles, all using same generic protocol biopsy. For this reason, various approaches have been developed last 2-3 years are increasingly making their way to clinic worldwide. design, size, duration as a first-tier test was implemented at UZ Leuven mid-2014, in-house algorithm (siCHILD/haplarithmisis). This retrospective analysis data, collected between 1 January 2015 31 December 2022. Data on indication, cycles biopsy results extracted. Implantation rate (IR; with IU/EU fetal sac) per transfer calculated frozen (FET) patients result by end 2021. Participants/materials, setting, methods By 2022, 718 couples successfully finalized preclinical workup. At time writing, 573 (80%) further proceeded cycles. In total, 1264 were performed day-3 (D3) cleavage-stage (n = 3344) trophectoderm (TE) biopsies 1524). 403 954 FET IR type ranking, considering information. Main role chance Couples referred due autosomal dominant (AD, 65%), recessive (AR, 14%) X-linked disorders (XL, 10%). Various PGT-M indications encompassed >200 genes but almost 20% enrolled inherited BRCA1/BRCA2 mutations. PGT-SR indication 7% cases, mainly microduplications/deletions (64%). approximately 15% 18% D3 TE biopsies, respectively, scored abnormal largely meiotic errors embryo. All unaffected embryos ranked R1 (euploid) R2 (mosaic), expectedly higher after compared (250/1063, 23.6% vs 37/510, 7.3%, p<0.001). accordance inheritance mode, suitable significantly lower AD AR (32.3% (1116/3455) 44.0% (262/596) ; p<0.0001)). (231/590, 39.2% 30/159, 18.9 %, p <0.0001), whereas no difference observed biopsy, although low transferred (85/142, 59.9% 7/12, 58.3%, p=ns). Limitations, reasons caution The analyzed data derived single center may not reflect experience other IVF/PGT centers confounding factors, such used technology IVF lab practice. Wider implications findings current dataset comprehensive overview general trends information chromosomes, which improves transfer. turn impacts counselling, interpretation reporting results, policies. Trial registration Not applicable