Ziva Cohen, a law school admissions officer in Manhattan, has noticed a change in her single friends' girl talk lately: As 40th birthdays approach, and the prospects of marriage remain unclear, some are starting to focus -- a lot -- on the idea of having their eggs frozen to fend off the relentless pressure of the biological clock.
In February, one 39-year-old friend even went ahead and did it, spending $12,000 for hormones and procedures that yielded eight frozen eggs. And among the rest, from chats over manicures to discussions over drinks, the topic has reached the feverish level usually reserved for real estate: "It feels like it's all around us," Cohen said. "It's on everyone's minds."
Such talk is good news for the nascent egg-freezing industry, which officially arrived in Boston last month when the egg-freezing company Extend Fertility launched a partnership with Boston IVF, one of the country's largest fertility clinics.
The bad news is that as egg freezing gets off the ground in a few urban centers, it seems to meet an essential clash between female biology and female psychology.
Cohen's friends tend to be about 38 or 39, a common age for egg-freezing clients, early research suggests, but far from an ideal one. For most women to be willing to take the gamble of egg freezing, they must be emotionally ready to accept that they may not marry and have babies an easier way. And that tends to hit toward the later 30s, just as egg quality is often taking a nose dive.
Women are believed to be born with all the eggs they will ever have, and time takes a toll. Older women face higher risks of miscarriage, infertility , and chromosomal defects, apparently because egg quality declines. Using eggs from younger donors, women have given birth in their 50s and 60s; but the mid-40s generally seems to be the outer limit for a woman's own eggs.
"There we were, full of enthusiasm to help a new group of patients, but in our initial efforts, we realized we were attempting to preserve fertility in women who were already running out of good eggs," said Dr. Alan Copperman, director of infertility for Mount Sinai Medical Center in New York. "As we keep working on the science of egg-freezing, we also need to improve women's awareness of reproductive aging."
Last month at an infertility conference, Copperman presented his clinic's latest data on how advancing age hurts egg freezing results. The data over the last two years included 78 patients -- a large number in what remains a tiny field. Extend Fertility, headquartered in Woburn, has frozen eggs for only about 200 women nationwide, and estimates that a similar number has done it through other providers.
Freezing embryos rather than eggs is far more common and scientifically established, but it requires the woman to have a mate or donor sperm.
Copperman, who is on Extend's medical advisory board, reported that the older women were, the fewer eggs good enough for freezing they produced, with a particularly sharp drop off after age 37.
Also, he said, the older women were, the likelier they were to respond so poorly to stimulating hormones that it was not worth attempting to retrieve their eggs. Many women nearing 40 never get as far as the hormones, he said: They come in wanting to preserve their fertility, but already show such hormonal and physical signs of diminishing egg reserves that they are advised not to try. (Women who are wondering about their own reserve of eggs can have an ultrasound and blood test that will give them a sense of where they stand, he said.)
Drea Hoffman, a 41-year-old Los Angeles filmmaker, had her eggs frozen through Extend when she was 39 and found that she only produced six or seven eggs each time she was hormonally stimulated. An ideal harvest is 10 or more eggs.
She ended up going through three egg-freezing cycles to end up with 18 frozen, short of the recommended 20 to 30. She also froze five embryos made with donor sperm. All in all, she spent about $45,000, she said.
Currently single, she hopes to meet someone and conceive naturally, but "I think it's great to have the options" her frozen eggs give her, she said. "I think I'll have some decisions to make in the next couple of years," she said.
Extend founder Christy Jones said that women generally contact the company for information at an average age of 35, but go ahead and have their eggs frozen at an average age of a few months over 37. Extend's cut-off age is 40, and some clinics set it lower.
"There definitely is a disconnect," she said, and Extend is trying to spread the word that egg-freezers should do it sooner rather than later, because of the fall-off in fertility.
Mid-30s might be the right time, said Dr. Michael Alper, medical director of Boston IVF. Eggs are still likely to be good, he said, and "somebody has a sense of whether Mr. Right is around the corner or not, and they can make an intelligent decision."
Freezing in the 20s seems early, he said, because the chances are pretty good a woman will never use the frozen eggs.
Boston IVF has been freezing eggs as part of a research protocol since 2005. It announced its first pregnancy from a frozen egg this spring. But it has yet to freeze a woman's eggs as part of its new partnership with Extend. An Extend client can expect to pay $10,000 to $12,000 for the initial retrieval, freezing at a Newton facility, and one year of storage, plus $2,000 to $4,000 for fertility drugs. Frozen, the eggs may last indefinitely.
Boston IVF has received dozens of calls from interested women of all ages in recent weeks, Alper said, and goes through the pros and cons with them. If someone is 40, "we strongly discourage them," he said.
Many women may hesitate because medical authorities consider the entire egg-freezing process largely experimental. A review by Extend found that more than half of eggs survive defrosting; Jones said some providers are now up to 80 percent. At some clinics, it appears to be about as reliable as in vitro fertilization with fresh eggs; about one-third of embryo transfers result in pregnancy.
But the American Society for Reproductive Medicine says it remains too experimental to be endorsed for healthy women with no immediate danger to their fertility, such as impending chemotherapy. Patients receive no guarantees of future babies, and hormonal stimulation required to produce eggs can, in rare cases, pose health risks. Ziva Cohen's friend, Suzanne, had eight of her eggs frozen in February at New York University's fertility clinic, not through Extend. She was well aware that she was buying only a possible "insurance policy," she said. But she was 39, and "I was putting pressure on myself to make some sort of decision about what I was going to do by the time I turned 40."
She had always thought she would be married and have children by now, but "unfortunately, it has not worked out that way," said Suzanne, who asked to omit her last name for fear her decision might prove off-putting to potential dates. She thought deeply about becoming a single mother, she said, "but it really isn't something that I feel ready to do. And so I just felt this was a way to kind of hedge my bets a little bit. Maybe I will still have a child on my own, I'm not sure, but I'm still hoping for the dream, and if I can buy some time, great."
It is not that women like her postpone the decision consciously, she said; "I think that most women hold out because they want a man in their life," she said. "They keep pursuing relationships, hoping that things will just work themselves out."
Carey Goldberg can be reached at email@example.com.