FET - Frozen Embryo Transfer

How preserved embryos are prepared and transferred.

Frozen Embryo Transfer for IVF

Embryology lab at work in Dallas

Couples going through in vitro fertilization (IVF) often end up with more embryos than they need for their pregnancy. In those cases, Dallas-Fort Worth Fertility Associates is happy to offer couples a long-term option for their future family desires. We provide all of our IVF patients the opportunity to freeze the unused embryos for later use.

Embryo Cryopreservation

Freezing embryos is also called embryo cryopreservation. This is a very specialized procedure in which the remaining fresh embryos are dehydrated and flash-frozen in a process called vitrification. It’s very important to remove all of the water from the embryos before they are frozen because ice crystals can cause damage to the cells during the cryopreservation process.

Embryo Thawing

When a couple with one or more frozen embryos decides that they would like to expand their family, the frozen embryos can then be thawed. The thawed embryo is then transferred into the woman’s uterus in a modified cycle of IVF.

Frozen Embryo Transfer

Frozen embryo transfer is different than a fresh embryo transfer that occurs during the original IVF cycle or cycles. Because the egg or eggs have already been retrieved to create the frozen embryo, the woman’s ovaries don’t need to be stimulated.

When the woman is ready to start the process of frozen embryo transfer, she takes hormones to prepare the uterus to receive the embryo. This hormonal preparation typically takes between 3 to 4 weeks.

During this preparation time, the Dallas-Fort Worth Fertility Associates fertility specialist will check the woman’s hormone levels and the uterine lining to make sure the uterus is properly prepared. Once the uterus is ready, the cryopreserved embryos are thawed and transferred into the uterus. Pregnancy testing typically occurs 8 and 10 days after the embryo transfer.

Who Benefits from Freezing Embryos?

Cryopreservation of embryos is an excellent option for people who need to delay pregnancy for several reasons:

  • Fertility preservation for couples who are not ready to start or expand their families but are concerned about loss of future fertility
  • Couples who have just had a successful IVF cycle and want to have the option for future pregnancies without having to repeat the IVF cycle process

Success Rates for Cryopreservation and Frozen Embryo Transfer

Dallas-Fort Worth Fertility Associates provides some important facts to keep in mind regarding the frozen embryo transfer process:

  • Approximately 80 percent of fresh embryos survive the freeze-thaw process if vitrification is used
  • Approximately 40 percent of frozen embryo transfers at Dallas – Fort Worth Fertility result in a pregnancy
  • About 20 percent of all children born from IVF cycles worldwide are from embryo cryopreservation and frozen embryo transfer procedures.