CryoET
CryoET
FET – frozen embryo transfer
Frozen embryo transfer (FET) is a procedure in which we thaw previously cryopreserved embryos and return them in a natural or modified cycle.
Freezing all embryos is now a common trend and a new, very successful IVF technology. By forgoing fresh ET, all embryos created in IVF culture can be frozen at any stage of development:
- the pronuclear phase,
- day 3 of development - the cleavage phase or
- blastocyst.
Frozen oocytes can also be stored, and it is only in recent years, this strategy has become possible, as the success of freezing and FET is equal to or better than fresh embryo transfer. Thanks to these advances, top IVF centres are trying to achieve freezing and FET in 50% of patients today. There is also a growing focus on freezing all technology in 20-30% of procedures.
Double freezing (again, after thawing) has been found not to harm embryos.
