Common genetic variants affect risk of a major cause of pregnancy loss

Genetic data from 139,416 human embryos were used to characterize chromosomal abnormalities, called aneuploidies, that underlie many cases of pregnancy loss. This approach revealed a relationship between aneuploidy and the exchange of DNA between chromosomes during female meiosis and egg formation, and identified common maternal genetic variants associated with meiotic errors. Biopsies from human embryos fertilized in vitro enabled testing of factors that influence risk of abnormal chromosomal number.