Egg freezing was first used in the 1980s to help women cancer patients whose fertility might be compromised due to chemotherapy; but fewer than half of the eggs were able to survive the thawing process.
However, in the last few years, two things changed to push egg freezing into the mainstream.
First, clinics around the world have moved from the traditional slow-freezing technique to vitrification—a more rapid, more successful process that means, literally, changing a substance into glass. Scientists first place the egg into a solution that dehydrates it. Then they rapidly freeze it. When the eggs are warmed up, they survive at a rate of over 90 percent. With the old method, ice crystals often formed, damaging the cell membranes.
In 2010, doctors announced astounding success rates in a presentation at the 26th annual meeting of the European Society of Human Reproduction and Embryology in Rome. When 600 women underwent IVF with either frozen or fresh eggs, the pregnancy rate was 43.7 percent for vitrified eggs, slightly higher than 41.7 percent with fresh eggs. The fact that a frozen egg was as good as a fresh egg for IVF was big news.
The second boost came last fall. Because of the past failures, the ASRM had labeled egg freezing an “experimental” procedure in 2008, meaning that institutional review boards overseeing clinics and universities developed strict guidelines for how the procedure could be offered and how patients would be monitored. But back in October, after a year of review, the ASRM dropped the “experimental” designation—meaning that hundreds more clinics will offer the procedure as a first-line treatment just like IVF, with less stringent guidelines.
Samantha Pfeifer M’86, associate professor of obstetrics and gynecology, chaired the ASRM Practice Committee that recommended the change. Pfeifer works out of Penn Fertility Care, the Perelman School of Medicine’s fertility clinic, which is one of eight centers nationwide funded by the National Institutes of Health for clinical infertility research. Several of the doctors on staff are active with the ASRM.
Pfeifer had been involved with the group for several years when she was nominated to chair the practice committee. “The process of generating a document is incredibly precise,” she says. “I really enjoyed being in that environment, with great minds putting together information in that field.”
She sees both pluses and minuses with regard to the impending popularity of the procedure, which the changed designation will likely spur. “The first concern was, is the technique successful? We didn’t feel like we could recommend or advocate a technique where fewer than 50 percent of the eggs survived. It wasn’t until vitrification and further experience with the technique that we got good rates of survival. We saw studies that showed a 90 percent survival rate in young women,” she says.
“The second thing is that, the egg may survive, but did you destroy the genes, the material in the egg? Studies showed the mitotic spindle [which segregates chromosomes] was not significantly disrupted.”
The fact that the pregnancy rate and live-birth rates were the same for fresh and frozen egg donors “was very powerful information,” she adds. “The last thing was information on birth defects, since there have only been about 1,000 babies reported born from frozen eggs. There does not seem to be an increased risk of birth defects.”
On the other hand, Pfeifer does express some concerns about the uncontrolled spread of the procedure, particularly to practices that have little history with it. “Every program is going to start doing egg freezing now. It’s a great opportunity for patients, but also a moneymaker. In the beginning, some centers will not be very good at it,” she says. “Every procedure has a learning curve. Patients need to be aware that they just started doing this, and things have to be sorted out. Patients have to be counseled about the risks and benefits, and about what they are getting into.”
For example, Pfeifer wonders whether clinics would counsel older patients that their success rates will be much lower than for younger women freezing their eggs. Many of the studies on egg freezing were done with eggs from women under 30.
Clarisa Gracia GM’04, associate professor of obstetrics and gynecology, was also on the committee. Gracia is on the faculty of the Center for Research on Reproduction and Women’s Health and is the primary researcher into egg and ovarian tissue freezing for cancer patients at Penn Fertility Care. When it comes to elective egg freezing, she is a bit hesitant, and counsels her patients accordingly.
Since Penn began performing egg vitrification in 2009, “we’ve seen more and more healthy women who are freezing their eggs because they don’t have a partner,” Gracia explains. “They’re in their mid-30s and they’re worried they’ll be over 40 when they meet their partner, and they’re not going to be able to get pregnant. I don’t encourage it. We will do it, but the only way to guarantee having a baby is to get pregnant. I would say, ‘Would you want to use donor sperm and have a baby now?’”
She acknowledges that some women aren’t ready to have a child on their own. “There’s no perfect solution,” she says. “Most women in their mid-30s are probably going to have a partner and get pregnant on their own within the next five years, considering the statistics on women under 40 getting married, and they may not be able to use those [frozen] eggs. And the cost of the procedure is a lot.”
But women have been hit with a flurry of magazine and newspaper articles over the last 10 years that practically scolded them for waiting too long to do something about their fertility. In an infamous 2008 Atlantic Monthly essay called “Marry Him,” a fortysomething single mom exhorted her women readers to “settle” for “Mr. Good Enough” so they could have children at a young age. (The latest round in this ongoing cultural argument was launched in December with a story in The New Republic built around writer Judith Shulevitz’s experiences as an older parent, as well as some troubling research on potential children’s health effects and adverse social impacts associated with what the cover line teased as “The Grayest Generation.”)
“Society is tough on women,” Gracia says. “We expect them to do everything and have babies, and it’s hard, unless society changes so that women can find a partner and get pregnant earlier, which is really the root of the problem.”