Treatment with frozen embryos (FET)

If there is more than one good high-quality embryo in an IVF-treatment, the ones that are not transferred will be frozen in liquid nitrogen by -196⁰C. The embryos can later be thawed and transferred, either in af unstimulated/spontaneous cycle or in a hormone stimulated cycle.

​We only freeze embryos, that have developed to blastocysts (have been cultured in 5-6 days).

​Even though we are only freezing high-quality embryos, not all frozen embryos are surviving the freezing and thawing. In average 90% of the embryos survive the thawing.

According to Danish law, frozen embryos can only be stored for 5 years.

If the couple separates, or one of the parties dies, the embryos must be destructed. It can be agreed among the parties, that if the male part dies, the female part can use the frozen embryos. (The agreement must be written).

If the embryos origins from a treatment of a couple:

  • ​Both parties must consent to the freezing and storing of the embryos in writing.
  • ​The embryos can only be thawed and used, if both parties give their consent in writing before the thawing and transferring of the embryos.

The pregnancy rate after Frozen Embryo Transfer (FET) is 30-40%.

For women with regular cycles within 35 days, the thawed embryo is transferred in a normal cycle (unstimulated).

If a cycle is long (more than 35 days) or irregular, the endometrium is primed to receive the embryos, by using tablets or bandaids containing Estradiol (stimulated cycle).

Transferring thawed embryos in an unstimulated cycle

Transfer of thawed embryos is often done without hormone stimulation.

Once your period starts, you must call the clinic, to make an appointment for a scan of the endometrium day 10-12 in your cycle. The scan determines the thickness of the endometrium, and the size of the follicle.

When the follicle is mature (diameter 17-20 mm) an ovulation injection (Ovitrelle) is given. 6-7 days later the embryo is thawed and on the same day transferred in the uterus.

When the embryos are thawed, you must call the laboratory to know, whether they survived. The transfer procedure of the embryo is the same as in a fresh transfer cycle.

Transferring thawed embryos in a stimulated cycle

On the 2. or 3. day of your period, you will start with tablets containing Estradiol á 2 mg 3 times a day.
After 10-12 days you will have an ultrasound scan. When the endometrium is thick enough, the treatment with progesterone will start.

4-5 days after an embryo will be thawed and transferred. It is either transferred the same day as thawed, or the day after.

You must continue with the estradiol and progesterone until the pregnancy test. If pregnant, you must continue the treatment with estradiol and progesterone until you are 10 weeks pregnant.

Make an appointment 

Call us to hear how we can help you

We are always ready to answer your questions.

It can be a difficult situation, when fighting against involuntary infertility. We are always ready to help and give advice.

You are welcome to send us an e-mail or please feel free to call our fertility clinic at 

+ 45 70 70 20 75

Company information

​Freya Fertility ApS

​Orebygårdvej 3, 7400 Herning

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​Phone: 70 70 20 75


CVR: 40933344

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