Overview
- A Cambridge- and Crick-led team reported in Nature Biotechnology that some de novo mitotic errors appear late in preimplantation development.
- Researchers tracked thawed human embryos for about 46 hours using fluorescent nuclear tagging with light‑sheet microscopy to minimize damage.
- Across 13 embryos and 223 observed cell divisions, 8% showed chromosome misalignment and roughly 10% of cells carried abnormalities.
- Errors were confined to trophectoderm cells destined for the placenta, which are the same cells sampled by PGT-A, whereas inner-cell-mass cells showed no such events in this dataset.
- Clinicians and experts note the study’s small sample and uncertain clinical impact, with authors calling for further research and possible reassessment of transfer timing during IVF culture.