Egg freezing works to preserve fertility, new guidelines say

By Deborah Kotz, Globe Staff

Here’s good news for women who are thinking about freezing eggs from their ovaries because they’re not ready to have a baby -- and are worried that they’ll be too old when they are -- or are undergoing chemotherapy or radiation that might render them infertile. The technique really does work to achieve successful pregnancies and should no longer be considered experimental, according to new guidelines set to be issued Monday by the American Society for Reproductive Medicine.

That means that insurance companies will be more likely to cover the $12,000 price tag for egg storage -- at least in those with medical conditions that will destroy their fertility prematurely.

The medical organization, which represents infertility specialists and researchers, reviewed data from more than 100 studies on egg freezing or cyropreservation and found no evidence to suggest that the process damages the DNA within the egg or causes other structural problems that would give rise to birth defects or a diminished chance of pregnancy.

About 90 percent to 97 percent of eggs studied in randomized trials were found to be viable after they were thawed. About 40 percent to 60 percent of women in the studies who underwent in vitro fertilization using previously frozen eggs were able to achieve pregnancy on their first IVF attempt, which is similar to the success rate using IVF from eggs that were freshly harvested from women’s ovaries.

But, the society cautioned, these high success rates “may not be generalizable” to all fertility clinics because only those with the highest pregnancy rates tend to publish their studies. Researchers also tend to include only data from young, healthy women under age 30, so it’s tough to say whether a cancer patient or woman over 35 will have the same likelihood of getting pregnant from their previously frozen eggs.

While there aren’t enough safety data for the guideline authors to conclude for certain that egg freezing isn’t associated with any increased risk of birth defects, the experts called the studies reassuring: one that included 900 births from frozen eggs found no increased rate of birth defects such as Down syndrome or organ abnormalities compared with expected rates in the general population.

The guidelines recommended the use of egg freezing for women who want to preserve their fertility and have the following medical circumstances:

-- they are undergoing chemotherapy or radiation

-- they are planning to have their ovaries removed because they carry a BRCA gene mutation that puts them at high risk of ovarian cancer

-- they are undergoing IVF with a partner and prefer not to freeze their embryos for ethical reasons such as having to determine whether to destroy leftover embryos in the future.

But the experts stopped short of recommending that women freeze their eggs solely for the purpose of delaying childbearing, which means insurance probably won’t cover the procedure for that purpose. Data are lacking to determine how long success rates can be sustained as a woman ages. If women do opt for this, they should have their eggs harvested and preserved before age 38, the guidelines state, since research suggests that success rates drop significantly as eggs age beyond that point.