Freezing for IVF (In-Vitro-Fertilization) has been gaining popularity over the past years.
Single parents, older couples, and because of other social reasons, people have been turning towards cryopreservation( freezing of tissues and cells).
In this article, Dr. Hrishikesh Pai, one of the best IVF doctors in Nagpur, explains about cryopreservation. Cryopreservation is one of the best options for you , if you are considering having a baby in the future.
Below we will see what cryopreservation is,
What is cryo-preservation?
Cryopreservation is a process where biological constructs such as tissues, cells, organs, organelle (it’s a subunit within the cell), and extracellular matrix (which consists of a network made of molecules and minerals that provides support to the surrounding cell) are preserved for future use by freezing them under low temperatures ranging from ( – 80 °C using solid carbon dioxide or -190 °C using liquid nitrogen).
What is cryopreservation for IVF (In Vitro Fertilization)?
In IVF, cryopreservation uses Embryo, oocyte(eggs), semen, and ovarian tissue. These biological materials are frozen under extremely low temperatures, i.e., 321°F in liquid nitrogen; this process freezes the entire cellular activities and prevents cell damage.
Types of Cryopreservation for IVF
We shall see the different types of cryopreservation for IVF.
1. Embryo cryopreservation
In this cryopreservation method, Embryos (fertilized eggs and sperms) are frozen and stored for future use.
- The doctor selects the healthiest Embryo.
- Then the doctor uses cryoprotectant (a substance that prevents freezing of the cells) to replace the water content inside the embryo cells to protect the Embryo from damage.
- After the water is replaced, the doctor will use freezing methods to freeze the Embryo.
- We will see the two methods of freezing further in the article.
2. Oocyte cryopreservation
In this cryopreservation type, a woman’s eggs are extracted, frozen, and stored for future use.
- The doctor will use ultrasound to track the procedure.
- The doctor will insert a needle in the ovarian to retrieve the eggs.
- After the doctor has retrieved the egg, he will inject cryoprotectant to prevent the eggs from being damaged.
- In the final stage, the retrieved eggs are frozen under sub-zero temperature for the future.
3. Sperm cryopreservation
In this cryo-preservation type, sperms are frozen for future use. Sperms can be frozen for an indefinite period. IVF Mohali provides one of the best sperm cryopreservation treatments. The treatment is provided by Dr Hrishikesh Pai, best IVF doctor in Mohali.
- Before collecting sperm, the sperm donors undergo blood tests to check for diseases such as HIV, Hepatitis B, and Hepatitis C
- Once the sperm donors have cleared the blood tests, they will be asked to provide their semen to the lab.
- The lab technicians check the sperm’s quality in volume, viscosity, pH levels, and other important factors. Only the highest quality of sperms are selected for freezing.
- After the lab technician selects the sperm, it is injected with cryoprotectants.
- The sperms are frozen and stored for later use.
Methods of freezing
For cryopreservation there are two methods of freezing,
1. SPF( slow programming freezing)
In slow programming freezing, the cells are cooled very slowly with a decrease of 3º – 2ºC per minute until the temperature reaches -196ºC (Or – 320º F). Studies found that the SPF process results in a low survival rate of the cells. The process for SPF is simple but takes hours to complete.
Vitrification is ultra-rapid cooling, also called flash freezing. This process prevents the formation of ice crystals and helps in preventing damage. The cooling speed is transitioned from 37 to -196ºC in <1 s. Vitrification provides a glass-like solidification to the biomaterial. This process has a higher rate of survival than the SPF method. The process for vitrification is complex but gets over fast.