Frozen Embryo Transfer

Frozen Embryo Transfer (FET) – Comprehensive Guide

What is Frozen Embryo Transfer (FET)?

Frozen embryo transfer is the process of thawing previously obtained embryos that have been frozen and stored, and then transferring them into the uterus at an appropriate time.

Why is it Preferred?

It is preferred when embryo transfer needs to be postponed, if there is a risk of OHSS, if the uterus is not suitable, or when transfer is planned after genetic testing (PGT).

How Does the Process Proceed?

The FET process begins with the preparation of the uterine lining and concludes with the embryo transfer.

1. Uterine Preparation

The endometrium (inner lining of the uterus) is prepared with estrogen and progesterone, or a natural cycle can be followed.

2. Embryo Thawing

Frozen embryos are thawed on the day of transfer, and their viability is assessed.

3. Embryo Transfer

It is generally a painless procedure and is placed into the uterus under ultrasound guidance.

4. Luteal Phase Support

Progesterone support is given after transfer. This supports embryo implantation.

5. Pregnancy Test

Pregnancy is checked with a blood test approximately 10–12 days after the transfer.

Success Rate

With modern techniques, the success rate of frozen embryo transfers is similar to or, in some cases, higher than fresh transfers.

Advantages

• The uterus is prepared in a more physiological environment
• No OHSS risk
• Provides more flexible timing

Disadvantages

• Requires additional time
• May incur additional cost

Who is it More Suitable For?

• Those with a high risk of OHSS
• Endometrial incompatibility
• Patients undergoing PGT
• Freeze-all cycles

Conclusion

Frozen embryo transfer is a safe and effective method widely used in IVF treatments today.