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Journal Article Research Support, N.I.H., Extramural Epublish 34 citations

PubMed: 37779206 DOI: 10.1186/s13073-023-01231-1

Meiotic and mitotic aneuploidies drive arrest of in vitro fertilized human preimplantation embryos.

Genome Med 15(1):77

Authors: Rajiv C McCoy, Michael C Summers, Abeo McCollin, Christian S Ottolini, Kamal Ahuja, Alan H Handyside

Affiliations

  • Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21212, USA.
  • London Women's Clinic, 113-115 Harley Street, Marylebone, London, W1G 6AP, UK.
  • School of Biosciences, University of Kent, Canterbury, CT2 7NJ, Kent, UK.
  • Present Address: London Women's Clinic, The Chesterfield, Nuffield Health Clinic, 3 Clifton Hill, Bristol, BS8 1BN, UK.
  • London Women's Clinic, 113-115 Harley Street, Marylebone, London, W1G 6AP, UK. School of Biosciences, University of Kent, Canterbury, CT2 7NJ, Kent, UK.
  • Department of Maternal and Fetal Medicine, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK.
  • Present Address: Juno Genetics Italia, Via Di Quarto Peperino 22, 00188, Rome, Italy.

Abstract

BACKGROUND

The high incidence of aneuploidy in early human development, arising either from errors in meiosis or postzygotic mitosis, is the primary cause of pregnancy loss, miscarriage, and stillbirth following natural conception as well as in vitro fertilization (IVF). Preimplantation genetic testing for aneuploidy (PGT-A) has confirmed the prevalence of meiotic and mitotic aneuploidies among blastocyst-stage IVF embryos that are candidates for transfer. However, only about half of normally fertilized embryos develop to the blastocyst stage in vitro, while the others arrest at cleavage to late morula or early blastocyst stages.

METHODS

To achieve a more complete view of the impacts of aneuploidy, we applied low-coverage sequencing-based PGT-A to a large series (n = 909) of arrested embryos and trophectoderm biopsies. We then correlated observed aneuploidies with abnormalities of the first two cleavage divisions using time-lapse imaging (n = 843).

RESULTS

The combined incidence of meiotic and mitotic aneuploidies was strongly associated with blastocyst morphological grading, with the proportion ranging from 20 to 90% for the highest to lowest grades, respectively. In contrast, the incidence of aneuploidy among arrested embryos was exceptionally high (94%), dominated by mitotic aneuploidies affecting multiple chromosomes. In turn, these mitotic aneuploidies were strongly associated with abnormal cleavage divisions, such that 51% of abnormally dividing embryos possessed mitotic aneuploidies compared to only 23% of normally dividing embryos.

CONCLUSIONS

We conclude that the combination of meiotic and mitotic aneuploidies drives arrest of human embryos in vitro, as development increasingly relies on embryonic gene expression at the blastocyst stage.

MeSH

Genes, Blastocyst, Genomics, Incidence, Aneuploidy

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