What is frozen embryo transfer (FET)?

Patients who are undergoing IVF usually start their treatment with the aim to produce as many embryos as possible. The larger the number of high-quality embryos, the larger the chances of a healthy pregnancy as well. Ovarian hyperstimulation and the creation of many embryos often leads to left-over embryos, however. In many fertility clinics, these embryos can be frozen and used in frozen embryo transfer or FET at a later date. How does it work?

Frozen embryo transfer, and specifically the freezing of embryos, is strictly regulated in the United States. Medically speaking, the embryos have to meet certain requirements to qualify for freezing. These requirements, include the size, structure, and time from creation to freezing. Legally, there are limits on the length of time at which frozen embryos are allowed to be stored. In most cases, frozen embryos may be stored for a maximum of five years, though this can be extended under certain circumstances. FET offers parents the chance to have more than one child from one and the same IVF cycle. There are no indications that pregnancy after FET is any less successful than IVF with fresh embryos, and it is theoretically possible to get pregnant via FET many years after the creation of the embryo in question.

If you are undergoing IVF, FET may become an option for you in the future. So, who can benefit from frozen embryo transfer? To start with, those who end up with a large number of embryos after a regular cycle of IVF or ICSI. Women who are about to undergo medical treatment that has the potential of rendering them infertile are also suitable candidates for FET. Embryos created now can be transferred to her uterus at a later date. Finally, those who have already had their eggs harvested but then decide not to go ahead with IVF right away (for certain medical reasons, for example) can also freeze their embryos to use at a later date. You might also like to read about fertility clinics and egg cell donation.