FET – Frozen Embryo Transfer

Frozen Embryo Transfer is recommended to get pregnant to those couples who have specific health issues or circumstances as:

• Considering genetic screening (PGT) (most common indication)
• Considering an elective procedure
• When the consulting fertility specialist considers that a couple has a high chance of getting Ovarian hyperstimulation syndrome (OHSS)
• Transfer of fresh embryos not possible due to any medical reason
• Couples considering another child with the embryos created during one IVF cycle

Benefits of Frozen Embryo Transfer:

1. Increased Flexibility: With frozen embryo transfer, embryos can be stored and used at a later time, allowing flexibility in treatment planning. This is particularly beneficial for individuals or couples who may require multiple attempts to achieve pregnancy or who need to delay embryo transfer due to medical or personal reasons.
2. Higher Success Rates: FET cycles often yield higher success rates compared to fresh embryo transfers. The frozen embryo transfer allows for better synchronization of the embryo with the recipient’s uterine lining, providing an optimal environment for implantation and reducing the risk of certain complications associated with ovarian stimulation.
3. Multiple Transfer Attempts: Frozen embryo transfer cycles offer the opportunity for multiple transfer attempts from a single IVF or ICSI cycle. This can potentially improve the chances of pregnancy without undergoing additional stimulation and egg retrieval procedures.

The thawing process for embryos during a frozen embryo transfer (FET) cycle is carefully performed to minimize the risk of damage. However, it is important to note that there is a small chance of embryo damage during the thawing process.

Embryos are cryopreserved using specialized techniques and cryoprotectant solutions that help protect them during freezing and storage. The thawing process involves gradually warming the embryos to body temperature, typically in a controlled laboratory environment. This process is conducted by experienced embryologists who closely monitor and ensure the optimal conditions for embryo survival.

While the vast majority of embryos survive the thawing process successfully, there is a slight risk of damage or loss. Some factors that can affect the survival rate include the quality of the embryos, the expertise of the laboratory, and the specific freezing and thawing techniques employed.

To mitigate this risk, fertility clinics and embryologists follow established protocols and employ best practices to maximize the chances of embryo survival. Quality control measures, strict temperature control, and precise timing are implemented during the thawing process to minimize any potential harm to the embryos.

It’s important to remember that fertility specialists and embryologists have extensive experience in handling and thawing embryos, and their primary goal is to ensure the best possible outcome for the FET procedure. They will take every precaution to minimize the risk of damage and optimize the chances of a successful transfer.

During the initial consultation with your fertility specialist, you can discuss the clinic’s specific protocols, success rates, and any concerns you may have regarding the thawing process. They will provide you with accurate and detailed information tailored to your individual circumstances and offer guidance throughout the FET cycle.

Less Medication: Most patients are kept on a natural cycle with no medication and Frozen Embryo Transfer is carried out at the appropriate time. In others, minimal oral estrogen is good enough to prepare her endometrium.

Less Stress: Patients who use high-quality blastocyst-stage frozen embryos have a better chance of a successful FET cycle. With fewer cycle cancellations, cycles are also more predictable.

Better IVF planning: An IVF cycle including Preimplantation Genetic Testing (PGT) or Intracytoplasmic Sperm Injection (ICSI) can be better planned with frozen embryo transfer

Estrogen levels naturally peak soon before ovulation during the menstrual cycle. Ovulation is triggered by an increase in estrogen, which causes the ovaries to begin releasing progesterone. The endometrial lining of the uterus is then triggered by progesterone.

A fertilised egg must be implanted in the endometrial lining and continue to expand in order for a pregnancy to develop. Because the body produces progesterone in response to ovulation, the endometrial lining develops at the appropriate rate to nurture the fertilised egg in ideal circumstances. The optimum environment for implantation is when the progesterone response and endometrial lining development are in sync.

during IVF treatment ,TThe ovaries are stimulated via hormonal medications, and estrogen levels peak at significantly higher levels than in normal cycles. Progesterone production is triggered by this artificially generated estrogen peak.

Progesterone levels can become too high too soon, causing the endometrial lining to mature too quickly. The possibility of successful implantation is reduced when an embryo and endometrial lining are out of sync. The suppression of progesterone production is one of the reasons why IVF patients use medicines. However, these drugs may not work in some people, and they may still have problems with cycle desynchronization.

One technique to avoid desynchronization is to use frozen embryo transfer. Delaying embryo transfer until a later cycle allows your hormones to return to normal before starting, which may improve your chances of becoming pregnant. Embryos are generated and frozen rather than implanted while the body is still healing from IVF. The embryos are frozen and implanted once the body has recovered from the stress of IVF and has returned to a more normal cycle. Embryos are generated, biopsied, tested, and frozen during the first cycle. Once the biopsy findings have been received and the female partner has recovered from her egg retrieval, an embryo transfer will be scheduled.

• Desynchronization can be avoided by using frozen embryo transfer.
• Delaying embryo transfer until a later cycle allows your hormones to return to normal before starting, which may improve your chances of getting pregnant.

Fresh embryo transfer takes place during the same IVF cycle as IVF. In the lab, the eggs are extracted and fertilised. The embryos are allowed to mature before being returned to the woman’s uterus 3-5 days after being removed. Whereas, a woman undergoes IVF, her eggs are extracted and fertilised in the lab, and the resulting embryos are allowed to develop in a frozen embryo transfer cycle. Instead of being transferred back into her uterus on day 5 or 6, the embryos are frozen.

Preimplantation genetic testing can be done on embryos before they are frozen to screen for chromosomal problems. Once these results were received, the transfer would take place.

Freezing techniques like vitrification have evolved significantly in recent years to resemble spontaneous conception, resulting in higher pregnancy and live birth rates, fewer miscarriages, and healthier kids. The new vitrification approach significantly reduces loss rates compared to older slow freezing technology, which delivered few viable embryos.

High grade blastocysts have up to 40% chance of giving an ongoing pregnancy.