O-020 Aneuploidy and mosaicism in human embryos: How correct detection may improve IVF clinical outcomes

Abstract textStudy questionCan new next-generation sequencing (NGS) based strategies for preimplantation genetic testing of aneuploidy (PGT-A) improve clinical outcomes after assisted reproductive technology (ART)?Summary answerRecent randomised controlled trials (RCTs) suggest that NGS-based PGT-A strategies can improve clinical outcomes for older women. The clinical management of mosaic embryos remains controversial.What is known alreadyThere are two types of chromosome abnormalities present in embryos, meiotic arising mostly during oogenesis, and mitotic arising after fertilisation. Meiotic aneuploidies are present in all of the embryonic cells and in their vast majority are lethal. Conversely, mitotic abnormalities are present in only part of the embryonic cells with the remaining cells having a different cytogenetic constitution. This phenomenon is known as mosaicism. The sensitivity of NGS meant that mosaic aneuploidy became readily detectable in trophectoderm (TE) samples during PGT-A. The viability and clinical management of mosaic embryos has led to debates and controversies in the reproductive medicine field.Study design, size, durationThe study involved an assessment of the impact of mosaic chromosome abnormalities to embryonic viability and clinical outcomes after ART cycles using PGT-A via NGS. A large number of embryos generated in IVF clinics in Europe and the USA was examined.Participants/materials, setting, methodsEmbryos were generated by couples referred fo...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research