Eggs, sperm & embryos
1PN or 3PN zygotes have an abnormal chromosome complement, usually because two sperm entered the egg or a set of chromosomes failed to form properly. They are not transferred because of the risk of abnormal pregnancy.
Also known as: 3PN, 1PN, polyspermy
Related Canada guides
Sources
- Canadian Fertility and Andrology Society (CFAS)
Last reviewed: September 9, 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.