From Nature magazine

Egg freezing is no longer an experimental procedure, according to the American Society for Reproductive Medicine (ASRM), which on 22 October issued new guidelines on the controversial practice. The change in policy is expected to accelerate the growth of clinics that offer egg freezing to women who face fertility-damaging treatment for cancer or other conditions, and to women wishing to delay having a baby — although the society stopped short of endorsing the procedure for that purpose.

More than 900 babies have been born using the technique, which the ASRM called “experimental” in 2008. With that designation, the society approved of the use of egg freezing only in clinical trials overseen by an institution review board (IRB). Despite the ASRM policy, clinics have increasingly been offering the technique outside of this framework as a clinical service for a fee. Now the society is effectively giving such clinics a green light, a development that is likely to encourage consumer groups advocating for insurance providers to cover the procedure.

“This will open up the procedure for many, many people,” says Samantha Pfeifer, an associate professor of obstetrics and gynecology at the University of Pennsylvania, in Philadelphia, who headed the committee charged with making the recommendation. She adds, “There are enough preliminary data to say that this technique is safe.”

The committee removed the “experimental” label after analyzing more than 100 studies assessing the health of eggs after the procedure and the outcome of births. The committee concluded that there have been no reported increases in chromosome abnormalities or birth defects among children born using oocyte cryopreservation, the technical term for the procedure.

But the committee also noted that the data so far are incomplete — only four randomized clinical trials have been conducted using the technique. And while those studies suggest that the technique results in successful pregnancy in young women at the same rate as assisted reproduction with “fresh” oocytes, observational studies suggest the success rate is lower. Because the technique of freezing the large and fragile cells is relatively new, nothing is known about long-term effects on offspring that result from the method. Some studies suggest that babies born using assisted reproductive technologies are at an increased risk for certain rare disorders — the neurological condition Angelman syndrome, for example — that result from changes in the chemical modifications to DNA known as ‘epigenetic marks’.

The safety and success rates of the procedure have been the focus of heated debates among reproductive biologists. At the ASRM annual meeting in San Diego this week, for instance, Pfeifer will be facing off against Nicole Noyes, head of a clinic affiliated with New York University that offers the procedure. The topic will be whether younger women should consider freezing their eggs for the future, says Pfeifer.

Despite the need for more research, the new guidelines will help clinicians counsel patients about the technique’s safety and potential to result in a pregnancy, says Theresa Woodruff, chief of the Division of Fertility Preservation at the Feinberg School of Medicine at Northwestern University in Chicago, “It’s a good, measured step,” she says. The society announced its new policy on 19 October and published its new report yesterday in the journal Fertility and Sterility.

There were not enough data for the committee to recommend the procedure for women nearing the end of their reproductive years who wish to preserve their eggs for future use, says Pfeifer. And the data so far suggest that the success rates of the procedure decline with maternal age. Nonetheless, the use of egg freezing for delaying reproduction is a potentially huge growth area — many clinics are already offering these services.

This article is reproduced with permission from the magazine Nature. The article was first published on October 23, 2012.