Cleavage-stage embryo

A cleavage-stage embryo is one still dividing into more, smaller cells without growing overall — typically four cells on day 2 and around eight on day 3. Some transfers are done at this stage, particularly when few embryos are available and there is little to choose between them.

Also known as: day 2 embryo, day 3 embryo, cleavage embryo

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.