A very common question is why and when should women freeze their eggs? But what do women really know about the latest most commonly used method of egg freezing which is the vitrification process?
Vitrification is the process of flash-freezing in which the liquid nitrogen freezes the egg so it reaches a glasslike structure and thanks to this it is protected from injuries when being thawed. There are methods to prepare for the process of freezing like rigorous schedules for blood tests, ultrasounds and hormonal injections however it needs to be remembered that even this does not guarantee you a successful pregnancy in the future.
Report released by the Journal of the American Medical Association (Jama), Outcomes of Fresh and Cryopreserved Oocyte Donation released in August showed that success rates with IVF fresh cycles are higher than with frozen eggs cycles. Fresh eggs IVF showed a success rate of 56% while the frozen eggs cycles showed 47%.
An IVF specialist at Fortis Hospital in Bengaluru Manisha Singh said “Fresh eggs are better in terms of getting fertilized as not all frozen eggs survive thawing, thereby decreasing the chances available for the fertilization,”
Why egg freezing doesn’t always work?
Although cryopreservation has been in use for decades now it was October 2014 when it really reached its prominence. The date is when the two enormous US companies of Facebook and Apple declared they will pay up to $20.000 each of their female employees that wanted to freeze their eggs to pursue careers and postpone motherhood.
In the 1950s was the first time sperm was frozen. Embryos were frozen for the first time in 1980s.
However, freezing eggs was a lot harder. Why? Eggs are big cells containing water, while it’s being frozen the water in the cell also freezes and forms sharp crystals which could pierce through the nucleus. Furthermore inside the egg the chromosomal matter is stretched when it is being frozen which can cause further damage to the egg.
Nowadays the process of freezing is safer and the egg is better protected during the cryopreservation thanks to the flash-freezing process called vitrification which is now a commonly used method.
In this process oocyte (egg) is put into a bath with sucrose which is a sugar that draws some of the water out of the egg. After that it is placed into a highly concentrated cryo-protectant which protects the biological tissues from the damage caused be the freezing process. Then it is frozen in an instant in liquid nitrogen at a temperature of -196°C. This way ice isn’t formatted and instead the eggs is formed into a substance with a glass structure which protects the egg from injuries during thawing.
Director and head at Max Healthcare hospitals in Delhi Surveen Ghumman Sindhu said “We’ve had about 10-12 patients since the procedure was set up. Egg freezing for these women has been successful.” She also said that some women who were diagnosed with cancer decide on egg freezing to preserve their fertility not only from the devastating effects of the cancer itself but also from the damaging cancer treatments (chemotherapy)
Advancements in egg freezing
Egg cryopreservation was declared no longer experimental in January 2013 by the American Society for Reproductive Medicine. Sindhu said: “Vitrification is a far better technique. We started using it in India only after egg freezing was declared a standard procedure.” It was pointed out that a lot of the data came from Europe because only few clinics in the US were publishing the results of egg freezing.
The technology used in freezing and thawing the eggs has advanced which shows in better success rates using IVF with frozen eggs. Donors are healthy and young around their twenties when their eggs are of high quality. The success rates are lowered when the donors were older.
Sindhu said: “The age at which eggs are frozen obviously makes a difference. We mostly get patients above 35 years of age. The eggs may look alright, but a frozen egg from a younger woman is always better.” “The embryo has a better chance of surviving the thawing process and the eventual implantation,” she added. The problems do not lie only with the process itself but in the simple fact that very often women do not come back for their own frozen eggs.