What is Frozen Embryo Transfer?Dr Chinmayie R

Frozen Embryo Transfer (FET) is a part of IVF treatment where a frozen embryo is created using a complete IVF cycle, is thawed, and transferred into a woman’s uterus under ultrasound guidance. Embryos are transferred into a woman’s uterus by a simple, painless procedure.

In an IVF cycle, one or more embryos develop, and these embryos are usually frozen for later use. Usually, only one or two embryos are transferred into the women’s uterus during an IVF cycle as there are more chances of multiple pregnancies. The remaining embryos are frozen for future use. The embryos in day 2 (four-cell stage) – day 5 (blastocyst stage) are frozen to be used. These embryos are transferred to a freezing machine where the temperature is made to drop rapidly to -150 degrees Celsius and then stored in liquid nitrogen tanks at -196 degrees Celsius.

Sometimes even fresh embryos are transferred without freezing the embryos, and this is called a new embryo transfer or just embryo transfer. Freezing the embryo gives you more chances of pregnancy with one hormone stimulation cycle and egg retrieval. If that cycle has not resulted in pregnancy, the frozen embryo is transferred into the woman’s uterus, so you will not have to go through the hormone stimulation cycle again.

The success of the frozen embryo has increased substantially because the chance of pregnancy increases per egg retrieval from the uterus. It saves a lot of time and money.

Currently, GarbhaGudi follows a “Freeze-All” policy in IVF cycles as the success rates in FET are more than fresh transfers. The success rate in FET cycles depends on various factors like

> Quality of the embryos

> Culture condition

> Freezing and thawing techniques

> Quality of the media used for freezing and thawing

> Skills of the embryologist

> Embryology lab conditions

> Skills of the clinician who is transferring the embryo

> Luteal phase support that is given after the transfer

> The ability of the woman’s uterus to support the growth of the fetus