Embryo Freezing

It is a procedure that allows people to use embryos for later use. It involves freezing embryos Women do not wish to have children but their biological clock is ticking. Embryo freezing can be a great option for such women. This is sometimes carried out during IVF and is called cryopreservation. The additional embryos formed during IVF can serve for future family planning.

This article explains everything about embryo freezing, the time period taken, success rate and cost.


Reproductive endocrinologists are board-certified specialists who carry out this procedure. They are experts in understanding reproductive hormones. They are different from endocrinologists.


Embryo forms from the time the fertilized eggs divide until 8 weeks of pregnancy.

Step 1- Selection of embryo:

As a part of the IVF procedure, the woman is injected with hormones to produce more eggs. Men also produce more sperm, when these are fertilized several embryos develop. Usually, 4 embryos are transferred into the woman's womb. Out of the leftover embryos the healthiest ones are collected and stored.

Step 2- Removal of water content from selected embryos:

Water content is removed before freezing as this water could crystalise and cause expansion of the embryo leading to death. To prevent this water content is removed and replaced with cryoprotectants.

Step 3- Freezing of embryo

While removing the water the embryo is cooled to 20deg. This can be done in two ways

  • Slow freezing is where embryos are placed in a closed sterile container. The temperature is then lowered slowly from 20 degrees to -7degree celsius to -35deg celsius. The tube is then stored in liquid nitrogen at -195 degree celsius.
  • Vitrification is done without removing water content. The embryo is frozen quickly such that there is no time to crystalize. After this, it is stored in liquid nitrogen. It is a less common procedure as the chance of contamination is high.


This process is called embryo transfer. The carrier of the embryo would be put on stronger estrogen pills to build the lining of the uterus. After which progesterone is given to make the uterus more receptive. Under natural circumstances, the body is monitored until the 5th day of ovulation after which the embryo is transferred into the womb.

The process of transfer is done through the cervix by inserting a catheter through the vagina. And the embryos are carefully inserted through a syringe. After the procedure is completed the embryologist reads the catheter. This is done under the microscope to verify that the embryo is no longer on it. A blood pregnancy test is taken 10 days after the procedure to know if the transfer was successful.


  • Couple affected with genetic disorders
  • A person soon to go under chemotherapy and wish to have a family in future.
  • People are under medications that affect fertility.
  • Same-sex couples who wish to have children.
  • People who are approaching their advanced reproductive age and would like to keep the option open


Embryo freezing is known to have a high success rate. The highest chance of pregnancy is when these embryos are implanted within the age of 35. And they can survive the process of thawing up to 95%. These embryos are stored and monitored in hospital facilities, usually a lab or a hospital.


The complications occur during the extraction of eggs. The side effects are usually mild and temporary.

Some side effects seen are:

  • bloating or cramping
  • Vaginal bleeding
  • Cramps
  • feeling full
  • changes in vaginal discharge
  • infection
  • stimulation of ovaries


According to theory, these can remain viable for any amount of time. The embryos are kept sealed in a closed jar at -195 degree celsius in liquid nitrogen. During this process, no biological process like ageing can occur. The longest freezing time has been 19 years with positive embryo survival.

The storage time period depends on the country. Some countries have their time regulations for embryo freezing.


The cost depends on the region where the procedure is being done, the hospital or the clinic charges etc. There are insurance policies that cover this in the schemes. In India, it could cost anywhere from Rs 50,000 to Rs1,00,000 and upwards.


Embryo freezing is wonderful for couples that wish to have children but also have their biological clocks ticking. It is a safe and most effective way of inducing pregnancy. Possible risks include giving birth to a child with abnormalities. The current evidence is insufficient since this procedure is less frequently performed. These treatments are advised for couples that want to take the risk or are desperate to have a child at a later stage in life.

It is best to seek medical advice prior to and understand the procedure.

1. What will happen to the frozen embryos if it is not used?

It can be discarded, donated to someone else or for research or educational purpose. What if one of the partners decides not to continue with the procedure of freezing? Under such circumstances, the specialist suggests a waiting period. If still no, then the specialist cannot legally proceed with it.

2. What are the factors for successful transfer?

Both parents’ overall health is of utmost importance. • Age of the Mother at the time of the egg retrieval. • presence of polyps, irregular or any other hormonal condition. • Previous success or failure of fertility treatments

3. At what age can it be done the best?

The late 20s and early 30s are the best age. Is it better to freeze embryos than eggs? Freezing embryos have a higher survival rate. 95% of frozen embryos are able to survive. Apollo Fertility, Varthur , Bengaluru Call 1860 500 4424 to book an appointment

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