Embryo cryopreservation is the process of freezing and storing embryos and is a part of most in-vitro fertilization process. The cryopreservation process has been in use since 1983, and has resulted in the birth of thousands babies worldwide. The first baby from a cryopreserved embryo was born in 1986.
Following Artificial Reproductive Techniques such as IVF and ICSI, generally the number of embryos produced will exceed the amount that can be reasonably transferred to the women’s uterus. These extra embryos are often cryopreserved for future use. Only the healthiest embryos are frozen, and as a result this process has been proven to be very successful.
Reasons to choose Embryo Freezing:
There are several reasons to choose embryo freezing after an IVF cycle:
The pregnancy with the first IVF cycle is not successful
It can be used to have another child later
It is useful for men with low sperm count
Apt for women with inadequate endometrial development
The embryos could be saved and donated to someone else
Apt to use when one partner is to start cancer treatment
The embryos could be saved and donated for research
Embryo Cryopreservation – the process
Embryos are generally frozen from one to six days after they are made. The high-quality embryos are chosen and placed in a cryoprotectant solution (anti-freeze). Post-which they are frozen in a computer-controlled device. Embryos which are stored for long term are stored in liquid nitrogen, at a temperature of -196°C (-320°F)
There are two main techniques used for cryopreservation – Vitrification and Slow Programmable Freezing (SPF). In the slow freezing method, the embryos are frozen slowly, with the sequential addition of cryoprotectants. Vitrification is a much rapid and advanced technique that uses much higher strengths of Cryoprotective agents. This process changes embryos into almost solid-state like glass. In vitrification, instead of going through a phase change from liquid to solid, glass formation occurs. This process has less chances of ice crystal formation and thus less chances of embryo damage.
When needed, the embryos are carefully thawed. Thawing is basically a reverse process. The main aim of thawing is rehydration of the cell without damaging it. They are also soaked in special fluids to remove the cryoprotectant solution. Thawing takes only a few minutes.
The pregnancy rate after transfer of these embryos is consistently close to that of fresh embryo cycle. In fact, a recent case was reported in the news where a woman delivered a healthy child after using an embryo that was frozen for 24 years. A recent study in Finland, concludes that babies born using frozen embryo transfer actually have better health outcomes in several parameters as compared to babies born as a result of fresh embryo transfer.
So far, the best advantage of freezing embryos is for patients undergoing In Vitro Fertilization treatment. If a couple fails to achieve pregnancy in an IVF cycle, they can try the next cycle using embryos that are frozen from the first cycle. With frozen embryos, one doesn’t have to go through ovarian stimulation or egg retrieval. One doesn’t have to use estrogen or progesterone to thicken the uterine lining and prepare it to receive the embryo transfer. Hence, the next IVF cycles become less expensive, less invasive and less stressful.
At KJK Hospital, we use the advanced ‘Vitrification’ process for embryo freezing. For any questions on embryo freezing (cryopreservation), you can drop a message to www.KJKHospital.com/contact or call 9447452568 or 0471-2544080/2544706
