Frozen Embryo Transfer (FET)
Spare embryos from your IVF treatment can be frozen for future use, depending on their quality. Embryos are stored removing the fluid from inside the cells before freezing them in liquid nitrogen. Your embryos are stored removing the fluid from inside the cells before freezing them in liquid nitrogen. Your embryos can be stored for up to ten years for future treatment if your first cycle was unsuccessful or for siblings. Freezing is complex and you should bear in mind that success rates can be reduced when you are using frozen embryos.
A frozen embryo transfer can be either stimulated or unstimulated. During an unstimulated (natural cycle), the embryo(s) are replaced at the corresponding time in the cycle depending on the stage of embryo development.
With a stimulated cycle, you will need to take medication to go through the process of down-regulation. This temporarily shuts down your ovaries and prevents any eggs from being released. You will have a scan on day two or three of your period and start taking medication to prepare your womb for the embryo transfer. A second ultrasound scan at day eight or nine will be performed to check the thickness of your endometrium. Once it is of appropriate thickness we can start the embryo thawing process and book your transfer.
Our embryology team will inform you of how well your embryos have survived the thawing process and if they are of good enough quality for your transfer to take place. Sometimes embryos do not survive the thawing process. If this happens, we will book you a review appointment with one of our specialists to discuss your options going forward.
The embryo transfer is similar to a smear test. It may cause some minimal discomfort. The culture medium containing one of two embryos is loaded into a thin catheter with a syringe at the end. The doctor carefully guides the catheter through the vagina and cervix and deposits the embryo(s) into the uterus. Implantation begins three to four days later.