Preimplantation genetic screening reveals a high incidence of aneuploidy and mosaicism in embryos from young women undergoing IVF

The rates of mosaicism and aneuploidy in these embryos from young IVF patients are similar to those published for older women. We found the best confirmation rate after a diagnosis based on two cells, where both blastomeres showed the same chromosomal abnormality. In contrast, after a mosaic diagnosis the confirmation rate was low. The present study provides the first detailed reanalysis data of embryos analysed by PGS and clearly demonstrates the impact of mosaicism on the reliability of the PGS diagnosis