Frozen Embryo Transfer (FET)
Frozen embryos are those embryos that were not used during a fresh IVF cycle and were frozen to use at a later date. For a frozen embryo transfer, the embryos are thawed and transferred back into your prepared uterus. It does not require the ovaries to be stimulated as they are for an IVF cycle, however, it does require the uterine lining be thickened before transfer.
When is it used?
Frozen embryos seem to have an infinite life span. They can be used to expand your family when you are ready, after an unsuccessful fresh cycle if frozen embryos are available or after CCS.
What to Expect:
In order for the embryo to implant, the uterus must be ready for implantation. Typically, this means that medications such as the birth control pill, Lupron or Synarel will be prescribed to stop you from ovulating unexpectedly. Once your pituitary has been suppressed you will start to take estrogen to thicken the lining of your uterus. Monitoring through transvaginal ultrasound and blood tests will be necessary to make sure that the uterus is thickening as it should. Once the uterine lining is sufficiently thick, progesterone will be added and the Lupron or Synarel will be stopped. Progesterone matures the lining and makes it receptive to embryo implantation. Your transfer will be scheduled accordingly.
As with any transfer, there is always a risk of infection or bleeding. If you become pregnant, risks associated with pregnancy such as an ectopic pregnancy, miscarriage, premature birth or multiple birth can also occur.
Pregnancy success rates after a frozen embryo transfer are the same as that of a fresh IVF cycle. For women under the age of 35, pregnancy rates can be as high as 60 %.