Maternal age and genome-wide failure of meiotic recombination are associated with triploid conceptions in humans

Ploidy abnormalities affect over 1% of human embryos. Haploidy typically results from absent sperm DNA, while triploidy mainly arises from maternal meiosis II errors. Triploidy also shows a linear maternal age effect and can be characterized by genome-wide recombination failure, indicative of defective meiotic checkpoints during fetal development.