Embryo Freezing (Cryopreservation): Understanding Its Purpose, Process, and Success Rates

Embryo Freezing is an important medical process. It helps people to preserve their embryos at freezing temperatures. These can be used by an IVF doctor in Kolkata in the future, when those opting for the process are ready to get pregnant.    

Purpose of Embryo Freezing 

  The process is mainly used for preserving fertility. People who undergo medical treatments such as radiation or chemotherapy may have their reproductive health affected adversely. Thus, they can opt for this process.  It is also a good option for women who would like to delay pregnancy for some reason, such as to pursue career goals or to wait for a specific partner, but do not want to affect their chances of conception.    

The Process of Embryo Freezing 

  At any top IVF center in Kolkata, this is the stepwise process that is generally followed:   

• Ovarian Stimulation and Egg Retrieval 

This is the first stage, where doctors use hormonal medications to stimulate the ovaries, for the production of multiple eggs. Then, these are retrieved from the ovaries, under careful supervision. The process is generally out under sedation.    

• In-Vitro Fertilization (IVF) 

This is followed by the actual IVF process. In a laboratory dish, the eggs retrieved from the ovaries are fertilized with sperm. The embryos obtained from this fertilization are cultured in the lab for some days.    

• Embryo Assessment and Selection 

Following this, the quality and viability of the embryos are appropriately assessed. Generally, only the most superior embryos are chosen for the stage of freezing. Embryos can be frozen in various stages ranging from 2 to 8 cell or blastocyst stage.   

• Embryo Freezing (Cryopreservation) 

Next, the embryos are placed in a cryoprotectant solution. This helps to avoid the formation of ice crystals while freezing. Often, vitrification and other fast-freezing methods are used to ensure minimal embryo damage. Then, the embryos thus frozen are stored in liquid nitrogen tanks at a temperature of -196°C (-321°F).   

• Storage and Thawing 

When needed, the embryos can be thawed and prepared for transfer to the patient's uterus after being stored in liquid nitrogen for several years.  

• Embryo Transfer 

The embryos that are thawed are then implanted into the uterus for pregnancy. Patient needs to be on medication for one cycle when embryo transfer is planned and using blood tests and USGs optimal time for embryo transfer is selected.     

• Post-Transfer Care 

Patients may require medications from their IVF doctor in Kolkata. They may need to follow some specific directions to support the implantation and growth of the embryo.    

• Success Rates of Embryo Freezing 

Over the years, the success rates for the process have improved significantly, thanks to in vitrification advancements.  Vitrification allows embryos to reach freezing temperature in seconds.    For women who are less than 35 years of age, the success rate is around 60%, as per research.   The quality of the embryos and the age of the person at the time of freezing are two major factors that determine the success of future pregnancies. The expertise of the doctor involved and the quality of treatment at the preferred clinic also matter a lot in determining the success of the process.     FAQs:   

• What is embryo freezing and why is it done?

The process involves preserving embryos for use in future. It can be done for various reasons such as to allow for preimplantation genetic testing, for increasing the chances of successful outcomes in IVF and for delaying pregnancy.   

• How does the embryo freezing (cryopreservation) process work?

The process involved freezing the embryos at very low temperatures, generally in liquid nitrogen, to preserve them for use in the future. This process includes using healthy embryos, removing water content from them using cryoprotectants and cooling them rapidly, to avoid the formation of ice crystals. This halts the embryo development and enable for future use.   

• How long can frozen embryos be stored safely?

It is possible to store these indefinitely, although the standard storage period is only of 10 years as per the latest ART law. If wishing to store beyond 10 years permission is granted specifically fir oncofertility patients with permission from National Board. The optimum storage time can be influenced by practical considerations, such as IVF center in Kolkata policies and requirements of couple.    

• How many pregnancies using frozen embryos end in success?

Success rate is variable, although it generally ranges from 50 to 60%. There can be between 50 and 60 pregnancies for every 100 Frozen Embryo Transfer (FET) cycles. Over 95% of frozen embryos survive the thawing process such rates depend on maternal age embryo quality uterine status (preparation) and cryopreservation techniques.   

• Is embryo freezing safe for the baby and future pregnancy?

Yes, the process is generally regarded as quite safe for both the baby and future pregnancy. While some possible risks are associated with any fertility treatment, there are no inherent risks of health issues in babies or any complication risks in pregnancies due to the embryo freezing process itself success rates in frozen ET and fresh transfer are comparable.   

• What are the costs involved in embryo freezing and storage?

The overall embryo freezing IVF treatment cost can vary, depending on various factors such as the choice of clinic, number of cycles and type of technology used in the process.     With medical technology advancing a lot in the recent years, embryo freezing now comes with very high promise of success. For many people out there, it opens up the path to parenthood.