Chromosomal concordance between babies produced by the preimplantation genetic testing for aneuploidies and trophectoderm biopsies: A prospective observational study.

OBJECTIVES:Contributed to the development of next-generation sequencing (NGS) technology, more and more chromosomally mosaic and aneuploid embryos are discovered during the preimplantation genetic testing for aneuploidy (PGT-A) cycles. Because mosaicism and aneuploidy are routine phenomena throughout human pre- and post-implantation development. The benefit of implanting such mosaicism or aneuploidies detected by precise NGS remains controversial. This study aimed to investigate chromosomal concordance between babies produced by PGT-A and trophectoderm (TE) biopsies, and whether precise NGS resolution would reduce the development of an abnormal embryo in PGT cycles. STUDY DESIGN:Peripheral blood samples from 17 PGT-A babies were collected to compare with TE biopsy results at different NGS resolutions. RESULTS:16 euploid embryos diagnosed by 10 Mb resolution developed into 16 healthy babies with normal copy number variations (CNVs). One mosaic embryo diagnosed by both 10 Mb and 4 Mb resolution also produced a euploid baby finally. Among them, four euploid embryos diagnosed by 10 Mb NGS, showed segmental aneuploidy at 4 Mb NGS resolution. Four of them developed into euploid babies with normal CNVs finally. CONCLUSIONS:NGS at 10 Mb resolution is accurate enough to diagnose viable embryos. A more precise NGS resolution (e.g., 4 Mb resolution) results in discard of some potentially viable embryos. It is suggested to analyze the TE biopsy at both 10 Mb and 4 Mb resolutions to identify embryos with adverse chromosomal aberrations, but using 10 Mb resolution for guide transfer to increase a development chance of an embryo. TRIAL REGISTRATION:www. CLINICALTRIALS:gov, identifier ChiCTR2100042522.