For Patients Infertility Explained ART Frozen Embryo Transfer Frozen Embryo Transfer
A single IVF cycle can create more embryos than are safe to transfer in that initial cycle. Patients may then choose to cryopreserve, or freeze, the excess embryos for subsequent pregnancy attempts. Embryos can be frozen at different stages of their development. For more information about frozen embryo storage, see our Frozen Stored Embryos FAQ page.
When patients wish to proceed with using their previously frozen embryos, the Frozen Embryo Transfer (FET) is less complicated physically and financially. For example, ovulation-inducing medications are not necessary. Generally, FET can cost 70 percent less than an IVF cycle using "fresh" embryos.
Depending on the woman's overall health, her cause of infertility, and how much time has passed since the last IVF cycle, additional assessment testing may be required before FET. The medical team and patients will discuss a recommended number of embryos to be transferred.
Embryos will be rapidly thawed the morning of the transfer. Most blast embryos – about 95 percent – usually survive the thaw. If at least half of an embryo's cells are alive, it is said to have survived the thawing process. Even embryos with only half of its cells living can result in normal pregnancy. Embryos that are not considered good quality will not be refrozen after thawing.
The actual transfer procedure is similar to that performed in fresh embryo transfer. A blood test is conducted 9 to11 days following transfer to determine if the patient is pregnant.
