What is a Frozen Embryo Transfer?

After an IVF procedure is performed, the Frozen Embryo Transfer (FET) is a procedure that allows embryos from a previous IVF cycle to be implanted to help the couple achieve the goal of pregnancy.  In this blog we will explore what a Frozen Embryo Transfer is, how it works and the advantages of a Frozen Embryo Transfer procedure.  

An FET is a technique used in IVF where embryos created during a IVF retrieval cycle are frozen (cryopreserved) and stored for future use.  Sometimes the embryos are tested for disease before they are frozen. Most embryos are frozen at the blastocyst stage which is a Day 5, Day 6 or Day 7 embryo.  The actual FET process involves thawing of the frozen embryos and transferring the embryo in the female partner's  or gestational carrier's uterus.  

Typically with a FET the female partner is prepared for transfer with hormones.  The medications used are estrogen and progesterone.  Pregnancy rates are significantly higher with a hormone prepared cycle. Once the uterine lining is receptive to the embryo as determined by ultrasound the frozen embryos are then thawed in the laboratory and prepared for transfer.  The transfer procedure is usually painless and not require anesthesia in most cases.  After the embryo transfer a pregnancy test is performed around 10-14 days later.

Benefits of an FET

Since the FET does not involve ovarian stimulation and egg retreival it reduces the risk of ovarian hyperstimulation a serious complication of IVF. 

By freezing and storing embryos couples can transfer one embryo at a time decreasing the risk of multile pregnancy

By freezing excess embryos from a single IVF cycle, couples can save on costs for future pregnancies. 

By freezing embryos it allows time for Preimplantation Genetic Testing to be conducted on embryos, which improves IVF success per transfer and reduces costs when there are multiple embryos.