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Frozen Embryo Transfer (FET)

Frozen embryo transfer (FET) is a fertility treatment in which a previously frozen embryo, created through in vitro fertilization (IVF), is thawed and placed into a woman’s uterus. FET allows individuals or couples to use embryos stored from an earlier IVF cycle, providing another opportunity for pregnancy without undergoing a new egg retrieval process. The FET process offers flexibility as it allows patients to plan the timing of potential pregnancies.

FET involves several steps:

  • Initial Consultation and Planning
  • Endometrial Preparation
  • Thawing the Embryo
  • Embryo Transfer
  • Post-Transfer Support
  • Pregnancy Test

FET Step 1: Initial Consultation and Planning

Dr Lindheim reviews your medical history, previous IVF cycles, and the quality of your frozen embryos. Together, a plan is developed for your FET cycle, including whether a natural or medicated cycle is recommended. 

FET Step 2: Endometrial Preparation

The timing of the transfer is critical and is synchronized with your menstrual cycle. During this step, the goal is to prepare the uterus for implantation. There are two common approaches:

  • Natural cycle FET: For women with regular ovulation. The cycle is timed to your body’s natural ovulation, with minimal or no medication.
  • Medicated cycle FET: Hormones like estrogen and progesterone are used to control and thicken the uterine lining in order to optimize the timing for transfer.

Monitoring during the part of the cycle includes:

  • Ultrasounds to check the thickness of the endometrium.
  • Blood tests to measure hormone levels.

FET Step 3: Thawing the embryo

On the day of transfer, the embryo is carefully thawed in the lab. The embryologist will assess the embryo to ensure it has survived the freezing/thawing process and is suitable for transfer.

FET Step 4: Embryo Transfer

The transfer procedure is generally quick, painless, and similar to a routine gynecological exam. You may experience mild cramping, but no anesthesia is typically needed. A thin catheter is guided through the cervix into the uterus, and the embryo is placed in the optimal location. Ultrasound guidance is used to ensure precise placement. After the transfer, we recommend that you rest for a short period before resuming your normal activities. 

FET Step 5: Post-Transfer Support

Hormonal support with progesterone (begun prior to the transfer) continues for several days to help maintain the uterine lining. It is recommended to avoid strenuous exercise and intercourse during this time.

FET Step 6: Pregnancy Test

About 9 to 12 days after the transfer, a blood test (beta hCG) is done to determine if the embryo has implanted successfully and a pregnancy has begun. If the result is positive, hormonal support with progesterone is continued. Blood tests will be repeated over the next two to four weeks to be sure the pregnancy is progressing normally. An ultrasound will be performed approximately two to three weeks after the first pregnancy test to visualize and assess the pregnancy.