Researchers shed new light on egg freezing success rates

The study, "Age-specific probability of live birth with oocyte cryopreservation: an individual patient data meta-analysis," was published in the online May issue of the American Society for Reproductive Medicine's journal Fertility and Sterility.

Egg freezing is a relatively recent technique which enables women to preserve their fertility for medical or elective reasons. Until now, women who were undergoing oocyte cryopreservation, or egg freezing, were unable to predict their chances of a live birth once the eggs were reimplanted. Oktay and his team collected raw data from 10 previously published studies on egg freezing, allowing them to amass what may be the world's largest database on pregnancy outcomes after egg freezing. Using this database, which included data from 2,265 egg freezing cycles in 1,805 women in the U.S. and Europe, the researchers generated norms which can be used to determine egg freezing success rates based on a woman's age, the number of eggs frozen, and the method of egg freezing.

"Because of this breakthrough, women and fertility doctors will now be able to use a live pregnancy rate estimator to calculate their individual chances and to make a well-informed decision about the procedure," said Dr. Oktay.

The study also showed that while egg freezing success rates decline with age as expected, there is a sharper drop after age 36. Though pregnancies can result from frozen eggs implanted as late as age 44, the success rates are less promising after age 42.