The success of oocyte cryopreservation depends on the age of the patient?

Working together, experts from New York Medical College and the University of California became the first to identify the relationship between the successful outcome of IVF with frozen eggs and the age at which the patient has resorted to cryopreservation.

An idea that young women who, for one reason or another want to postpone having children, need to freeze their eggs, so that by the time they are ready for kids, they are able to use their own "young" biological material, is now gaining increasing popularity. However, until now experts could not predict the chances that the egg is successfully thawed and maintains its viability.

The Fertility and Sterility journal reports that the researchers headed by Kutluk Oktay, having examined the results of 10 previous studies in this area, including the data on 2,265 cycles of cryopreservation for 1805 women from the U.S. and Europe, managed to create the largest database of outcomes of pregnancies after IVF with frozen eggs.

Thanks to this database the American professionals for the first time managed to find a number of laws that allow to predict the chances that the egg won’t be damaged during defrosting and will remain viable. It turned out that the main criterion for the success of the operation is not a method or speed of cryopreservation, but the age of the patient at the time of the procedure. For example, the scientists have determined that after 36 years the chances of eggs survival after the thawing begin to decline significantly, and after 44 they reach a critically low level.

It’s believed that the use this database will help doctors to evaluate the chances of success of oocytes cryopreservation in a particular age, and possibly make a choice in favor of a different method of fertility preservation (eg, cryopreservation of embryos).

I must say, the results obtained by the U.S. experts are predictable. It is no secret that with age, egg quality declines. This is confirmed by a recent study of the team of scientists from the University of Newcastle, according to results of which women in middle age are more likely to produce unhealthy eggs because of the reduction in the level of special proteins - cohesin. For example, if the level of these proteins isn’t enough, the structure of the egg becomes flexible and soft, what leads to negative consequences, such as infertility, spontaneous abortion, and may provoke the development of serious diseases of the unborn child, such as Down syndrome.

It doesn’t mean that the American scientists labored in vain, proving the obvious. New objective researches help to improve the technologies of infertility treatment, and each of them has its own importance for the development of assisted reproduction. And yet, the most important thing I would suggest to pay attention to is the careful selection of the clinic, because what certainly affects the success of the procedure, are qualification of the doctors and the quality of media.