In medical terms, FET stands for Frozen Embryo Transfer. It is a common procedure in fertility treatments, primarily within the context of In Vitro Fertilization (IVF).
A Frozen Embryo Transfer (FET) cycle is a process designed to help individuals become pregnant. This process specifically utilizes embryos (fertilized eggs) that have been previously frozen. During an FET cycle, these frozen embryos are carefully thawed and then placed into the uterus, aiming for successful implantation and pregnancy.
Key Aspects of Frozen Embryo Transfer (FET)
| Aspect | Description |
|---|---|
| Full Name | Frozen Embryo Transfer |
| Purpose | To facilitate pregnancy using embryos preserved from a previous IVF cycle. |
| Embryos | Fertilized eggs that have undergone cryopreservation (freezing). |
| Procedure | Thawing of frozen embryos followed by their transfer into the patient's uterus. |
| Context | An integral part of modern fertility treatment, often succeeding an IVF cycle. |
The FET Process Explained
The FET cycle involves several steps to prepare the body for embryo transfer and implantation:
- Uterine Preparation: The recipient's uterus is prepared for the embryo transfer, often with hormone medications (such as estrogen and progesterone) to thicken the uterine lining and make it receptive to the embryo.
- Embryo Thawing: On the day of the transfer, the selected frozen embryos are carefully thawed in a laboratory. The success rate of thawing is generally very high.
- Embryo Transfer: Using a thin, flexible catheter, the thawed embryos are gently placed into the uterus through the cervix. This procedure is typically quick and usually requires no anesthesia.
- Post-Transfer Care: After the transfer, patients often continue hormone support and are advised to rest. A pregnancy test is typically performed about 10-14 days later to determine if the transfer was successful.
Why is FET Used?
FET offers several advantages and is utilized for various reasons:
- Utilizing Excess Embryos: After an initial IVF cycle, if there are more healthy embryos than needed for immediate transfer, these can be frozen for future use. FET allows these embryos to be used without undergoing another full IVF stimulation cycle.
- Preventing Ovarian Hyperstimulation Syndrome (OHSS): If a patient is at high risk of OHSS during a fresh IVF cycle, all embryos can be frozen, and a transfer can be performed in a subsequent, milder cycle, reducing the risk of complications.
- Preimplantation Genetic Testing (PGT): Embryos can be biopsied for genetic testing, then frozen. The FET can be performed once the genetic results are known, allowing for the transfer of only genetically healthy embryos.
- Optimal Uterine Environment: Sometimes, the uterine environment is not ideal during a fresh IVF cycle. Freezing embryos allows the patient to recover and for the uterus to be optimally prepared in a separate cycle, potentially increasing success rates.
- Family Building: FET provides an opportunity for couples to have more children from a single egg retrieval process, years after their initial IVF cycle, or if the first fresh transfer was unsuccessful.
