Next-Generation Sequencing Revealed that High Proportion of Human Embryos Resulted from Donor Eggs Are Segmental Chromosome Abnormal

Abstract

High proportion of human embryos produced by in vitro fertilization (IVF) are aneuploidy or have segmental chromosomal errors. Not only a whole chromosome aneuploidy, but also small errors in a chromosome, such as microdeletion can be detected by current next-generation sequencing (NGS) for preimplantation genetic testing (PGT). The prevalence of aneuploidy in donor egg IVF was significantly different between fertility clinics. In the present study, we examined whether different embryo biopsy procedures affect embryonic aneuploidies in donor egg IVF. We did not find significant differences in the samples with abnormal chromosomes between two biopsy methods. When we further analyzed the samples with abnormal chromosomes, we found that 64.0–80.7% of the abnormalities were whole chromosome aneuploidies while 19.3–36.0% were segmental chromosome abnormalities. High embryo implantation rates were obtained after transferring screened euploid blastocysts. These results indicate that blastocyst biopsy procedures may not significantly affect embryo’s chromosomal status, but PGT by high-resolution NGS revealed that high proportions of human embryos derived from donor eggs are not only aneuploidy, but also segmental chromosome abnormal, and screening of small chromosomal errors by NGS is beneficial to patients who use donated eggs for infertility treatment.