What is FET?

During an IVF/ICSI cycle, additional good quality embryos that are produced can be frozen and stored in a special cyroprotectant that protects them.

The FET cycle involves thawing the frozen embryo and transferring it into the uterus at the appropriate time of the cycle.

In comparison to an IVF/ICSI egg collection cycle, the FET cycle is relatively non-invasive as it does not involve stimulation of multiple eggs or an egg collection procedure. With FET, embryos can be transferred in either a natural cycle or in a medicated cycle – depending on whether natural ovulation occurs.

The Frozen Embryo Transfer Process

The frozen embryo transfer process involves:

  1. Blood tests close to the expected time of ovulation to determine the optimal time for embryo transfer.
  2. It’s likely that you will also need an ultrasound scan to determine if you have adequate endometrial development prior to scheduling of the procedure. In some instances, a trigger injection may be required to ensure that ovulation has occurred.
  3. After ovulation, progesterone pessaries are used to maintain the endometrium (lining of the uterus). The progesterone pessaries will need to be continued for at least the first 7-8 weeks of any resulting pregnancy.
  4. Prior to the scheduled embryo transfer, an embryo is taken from storage and thawed. This may occur the afternoon on the day prior to or the morning of the transfer to ensure that the embryo development matches with the endometrium.
  5. The embryo transfer process is the same as the transfer of an embryo from an IVF/ICSI cycle. The process itself is simple and is similar to a pap smear.
  6. The process involves your specialist placing a small tube called a catheter through the cervix and into the uterus. Your embryo is prepared by a skilled embryologist within the lab, loaded in specialised syringe catheter and connected to the catheter in order to be carefully pushed into position.
  7. There is no sedation required with this procedure and once it’s complete you will be asked to rest for at least 30 minutes in bed within our comfortable recovery room.
  8. Approximately 2 weeks after ovulation, a blood test for progesterone and hCG (pregnancy hormone) will be carried out to see if there is evidence of pregnancy.

What are the risks associated with FET?

There are some risks associated with FET. They include:

Cancellation of the treatment cycle

If optimal endometrial development does not occur within the expected time frame, the cycle may be cancelled. The embryo(s) will not be thawed in this situation.

Embryos do not survive the thawing process

While rare, there is a chance of embryos not surviving the freezing/thawing process or go on to have adequate cell division.

It is estimated that 10% of embryos do not survive this process. Sometimes, a few embryos may need to be thawed so that at least one embryo can be suitable for transfer. Occasionally, the FET procedure may need to be cancelled if no embryos are deemed suitable for transfer.

What are the emotional support options?

At Concept Fertility, we have experienced counsellors here to help you along your journey. Our counsellors are there for you throughout the entire process and will provide you with the support you need.

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