Embryo warming

Embryo warming, sometimes still called thawing, is the laboratory process of bringing a vitrified embryo back from very low storage temperature to a state suitable for transfer. The embryology team checks the embryo afterwards to confirm thaw survival, meaning that its cells look intact and it has resumed normal appearance, before proceeding to transfer. Most vitrified embryos survive warming, but survival is not guaranteed for every embryo, and this is checked on the day of your planned frozen embryo transfer.

Also known as: embryo thawing, thaw survival, warmed embryo

Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.