For many couples or individuals who are undergoing IVF or ICSI, the treatment often produces spare embryos that can be frozen. This can provide reassurance for you in case the procedure is unsuccessful or because you wish to try for siblings in the future.
Depending on the quality of the embryos they can be kept in cryostorage in the clinic and a frozen embryo transfer, or FET, performed at a later stage. Embryos can be stored for up to ten years under current guidelines from the Human Fertilisation and Embryology Authority (HFEA).
There are many different ways to prepare the body for a frozen embryo transfer, all of which require the endometrial thickness (womb lining) to be increased in preparation for an embryo to implant.
Ultrasound scans are performed to measure the thickness of your endometrium, and at the appropriate time we arrange your transfer.
Transferring a frozen embryo then follows the same procedure as embryo transfer in a normal, IVF cycle. Once the embryo is thawed, it is assessed in the laboratory to ensure it is of suitable quality. Approximately 80% of frozen embryos survive the freezing and thawing processes. Success rates depend on the development stage and quality of the embryo when it was frozen.
It is then placed in the uterine cavity, guided by ultrasound. A pregnancy test is arranged 10 to 12 days later to assess success.