The reproducibility of trophectoderm biopsies - The chaos behind preimplantation genetic testing for aneuploidy

Chromosomal mosaicism is a common feature of early human embryos development. Mosaic embryos display very low rates of concordance between multiple trophectoderm biopsies and between multiple trophectoderm and inner cell mass biopsies using next-generation sequencing. The here presented data clearly demonstrate the limitations and shortages of the preimplantation genetic testing for aneuploidy screening test, which are not in alignment with WHO basic requirements. (C) 2020 Elsevier B.V. All rights reserved.