Aneuploidy

Aneuploidy means an abnormal chromosome number, such as an extra or missing chromosome. Most aneuploid embryos do not implant or end in early miscarriage; some, such as trisomy 21, can result in a live birth. The chance of aneuploidy rises significantly with the age of the eggs, which is the main reason live birth rates fall with age.

Also known as: abnormal embryo, chromosomally abnormal

Last reviewed: 8 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.