Embryo Freezing (Cryopreservation) & Frozen Embryo Transfer (FET)

Embryo Freezing (Cryopreservation) & Frozen Embryo Transfer (FET)

What is Embryo Freezing?

Embryo freezing is a process involving the freezing and storage of embryos for future use, especially in In Vitro Fertilization (IVF) treatments.

The procedure is also known as cryopreservation and is preferred by individuals who aim to preserve their fertility options for various reasons.

Why Would You Freeze Embryos?

Embryo freezing is an important aspect of reproductive technology. Because it offers a variety of benefits to individuals who plan their parenthood. Below are the reasons why individuals choose the freezing embryo option.

  • You are aging or need to have medical treatments like chemotherapy.
  • You would like to choose to delay being a parent due to career commitments, educational pursuits, or other personal reasons.
  • You are undergoing medical treatment that may affect your fertility.
  • Your surgeon applied for IVF egg collection, and you would like to wait for better timing and preparation of the uterus for implantation.
  • To have backup embryos in case your first attempt at IVF embryo transfer fails.
  • The frozen embryo technique allows time for comprehensive genetic testing of embryos.
  • Individuals who will undergo gender transition and wish to have biological children in the future may opt for embryo freezing.

What Happens Before Embryo Cryopreservation?

Embryo freezing is a great way in preserving eggs so that you can be a parent when you wish. Before the procedure, you will see your doctor, who will perform several tests to check if your body or overall health is suitable for the procedure.

The tests your doctor performs can include hormone level testing and ultrasound. This way, your doctor can evaluate your ovaries and uterus. After the tests, your doctor will prescribe injectable medications that stimulate your ovaries so that your body can produce multiple eggs.

Once your eggs are mature enough for the procedure, your doctor will retrieve them through a minor surgical procedure, which can also be called egg collection IVF.

Around the time of egg retrieval, the sperm of your partner or donor should be collected.

 

What is the Procedure for Embryo Freezing?

Embryo freezing procedure starts when eggs are retrieved and sperm are collected. An embryologist at the fertilization clinic performs egg harvesting with sperm. The fertilization team will then observe the embryo, which starts growing in a petri dish. This process takes about five to seven days.

During these seven days, the embryologist may perform genetic tests so that the one most likely to grow can be selected. The healthiest embryos are selected for cryopreservation, and the embryos will be frozen.

This procedure is also known as vitrification. As the last step, the embryologist replaces the water inside the frozen embryo’s cells and rapidly cools the IVF embryo with liquid nitrogen. This technique is used to prevent the damage of ice crystals in cells.

What is Frozen Embryo Transfer?

Embryo freezing process is followed by frozen embryo transfer (FET). The process is for individuals who have frozen and stored embryos after an In Vitro Fertilization cycle.

FET Frozen embryo transfer process can start with your initial contact with your clinic. After the initial consultation, your doctor or the fertilization team at the clinic will create an IVF frozen embryo transfer timeline after completing the paperwork.

A frozen embryo transfer timeline can be started after your uterus is prepared for the procedure. Your uterus can be prepared either with a natural cycle or hormone replacement therapy.

Natural cycle:

The natural FET cycle frozen embryo transfer timeline focuses on allowing the endometrium (the lining of the uterus) to thicken naturally, following your body’s natural cycle. The process is monitored through ultrasound, which tracks the growth of egg follicles in the ovary and the endometrium.

When these elements reach the desired size and thickness, ovulation is induced. The frozen embryo transfer process is scheduled, which is generally a week after this point. To support the endometrium during the latter half of the cycle, progesterone, either in the form of injections or pessaries, is usually administered.

Hormone Replacement Therapy (HRT):

If you have irregular cycles, your doctor may perform hormone replacement therapy to prepare the endometrium for a medicated frozen embryo transfer timeline. The process starts with taking estrogen throughout the cycle and introducing progesterone in the latter half.

To determine the optimal time to start progesterone, the fertility team and your doctor will monitor your endometrium via ultrasound. The frozen embryo transfer implantation timeline will be settled when your doctor observes that your uterus is ready after the HRT.

Embryo Thawing Procedure

Embryo freezing will end after our embryo's development. Your menstrual cycle is a key aspect of the IVF process. The fertility clinic thaws your embryos on transfer day and ensures that their developmental stage aligns precisely with the corresponding stage of your cycle. The thawed embryo is then taken for the transfer.

On Which Day of Cycle is Frozen Embryo Transfer Done?

Frozen embryo transfer is done about 3 or 4 weeks after the latest menstrual period. The FET cycle frozen embryo transfer protocol calendar is aligned with the woman's natural ovulation cycle.

Procedure for Frozen Embryo Transfer

Frozen embryo transfer starts with a slender catheter, which is used to gently introduce the embryo into the uterus through the cervix. Along with the embryo, a small quantity of culture medium is also placed inside the uterus to facilitate the process. This technique is typically carried out without the need for sedation, and most women experience only mild discomfort.

1 Frozen Embryo Transfer Success Rates

Frozen embryo transfer success rate has improved significantly in recent years due to advancements in embryo freezing techniques such as vitrification. While success rates vary depending on individual factors such as maternal age and embryo quality, studies have shown encouraging outcomes. To learn the possible success rate, you should consult with your doctor, who will evaluate both you and your partner’s fertility.

IVF Due Date

Embryo freezing is a long process that creates opportunities for those who wish to be parents in the future. If you complete egg freezing, embryo freezing, or embryo transfer processes, you may wonder about the due date after the transfer. Frozen embryo transfer due date generally differs from natural conception. Typically, the due date is calculated according to the age of the thawed embryo at the time of transfer.

For example, if a five-day-old blastocyst is transferred, the calculation for the due date would start from the date of egg retrieval, adding 266 days (38 weeks, which is the average human gestation period).

Faq

How much is embryo freezing?

Embryo freezing cost may vary depending on many different factors, such as necessary fertility treatments, medications, the number of embryos suitable for freezing, or a long-term storage fee. Therefore, to get an approximate cost, you should consult with your doctor.

What is oocyte cryopreservation?

Oocyte cryopreservation is a technique also known as egg freezing. The egg cryopreservation process involves the extraction and freezing eggs. The frozen eggs can be used for those who wish to delay parenthood. If you would like to freeze eggs, you should first consult with your fertility clinic or your doctor.

You will be informed of the egg freezing process in detail. In addition, your clinic will inform you about the freezing eggs cost which varies depending on each individual’s overall health and fertility. Lastly, egg freezing success rates are influenced by your age or the number of eggs frozen.

Where are frozen embryos stored?

Embryo freezing is performed at fertility clinics. Therefore, the frozen eggs or embryos are stored in your clinic. They are kept in liquid nitrogen tanks at temperatures of approximately -196 degrees Celsius (-321 degrees Fahrenheit) to ensure their preservation and viability for future use.

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