A frozen embryo transfer, or FET, is a kind of IVF treatment where a cryopreserved embryo created in a full IVF cycle is thawed and transferred to a woman’s uterus. The cryopreserved embryo may be from a woman’s previous conventional IVF cycle, or it may be a donor embryo. If a donor embryo is being used, the embryo is not genetically related to the woman or her partner.

Instead of stimulation medication, patients use estrogen and progesterone to thicken the lining of their uterus in preparation for the embryo transfer to allow implantation.