Five years after the freezing of human eggs stopped being considered experimental, the practice has gone mainstream in the United States.
Six percent of all companies with 500 or more employees now cover egg freezing as a health benefit, according to the human resources consulting firm Mercer. Egg freezing data have been added to the national report on fertility clinic success rates. Marketer EggBanxx has held cocktail parties to try to persuade well-heeled professional women to "mix, mingle, and preserve your fertility."
Still, oocyte cryopreservation is just beginning to catch on with such women.
Through 2015, about 20,000 U.S. women have put eggs on ice, about 2,000 of them have tried to use their stash, and about 450 have given birth, according to the most recent data from the Society for Assisted Reproductive Technology. And that includes an unknown number of women who froze eggs for medical reasons such as undergoing fertility-reducing cancer treatment.
In theory, stockpiling eggs to defy a biological clock should be booming, given the trends of delayed marriage and childbearing. Over the last decade, birth rates have fallen for twentysomethings, but are climbing for women in their 30s and 40s, federal data show.
In reality, though, preserving eggs to put off motherhood, or "social freezing," is an onerous, unpredictable, expensive process that requires considerable soul-baring. Even those who opt for it often feel more rueful than relieved.
Consider Elizabeth Holt, a 41-year-old technology professional in San Jose, Calif., who decided to freeze after confronting two facts: She's single. And she's "on my very last legs of fertility."
In an interview, she said she felt fortunate that her employer, technology giant Cisco, covered her $35,000 tab to build a precious cache of 15 frozen eggs last year. But that didn't spare her from friends' "well-meaning but totally not helpful comments" about her predicament.
"About how there's always adoption, about how you don't really need a father for a baby these days, or about how, don't worry, Janet Jackson had a baby at 50!" Holt wrote recently in a funny but fraught Facebook post. "As far as I can tell, the only acceptable thing to say to a woman who might tell you she's freezing her eggs is something along the lines of, 'Man, that's probably tough.' "
For women paying out of pocket, the cost is downright chilling. One cycle of extracting and freezing eggs runs at least $10,000. (Holt needed two cycles to get enough eggs.) Annual storage is about $1,000. Add the costs of thawing, high-tech fertilization, and implanting embryos, and conceiving a baby can easily cost $50,000.
But the most intractable obstacle is biology. By age 35, a woman has only about 3 percent of the eggs she was born with, and after that, the supply and genetic quality go downhill fast. Obstetricians call 35 and up "advanced maternal age" and a pregnancy in that age bracket "geriatric." If it's the woman's first pregnancy, she's an "elderly primigravida."
Indeed, the day Prince Harry and Meghan Markle announced their engagement, a leading national fertility clinic chain pounced with this story pitch: "Can Meghan Markle Get Pregnant?" She's 36.
The bottom line: The older the woman is when she freezes her eggs, the lower her chances of winding up with a baby.
Yet freezing youthful eggs is also a gamble.
"Most women in their early 20s go on to have healthy pregnancies naturally. They may store incredibly high-quality eggs, but never use them," explains FertilityIQ, a website that evaluates fertility clinics, treatments, and research.
Considering all this, professional medical groups have been torn about social freezing. European fertility specialists have given thumbs up, but the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine (ASRM) have not.
In 2012, when the ASRM declared egg freezing was no longer experimental because pregnancy rates were comparable to using fresh eggs, it said the technology should be reserved for women with medical needs.
"Data on the safety, efficacy, cost-effectiveness, and emotional risks are insufficient to recommend" social freezing, ASRM asserted. "Marketing this technology for deferring childbearing may give women false hope."
No wonder big employers who began offering social freezing as a perk faced criticism.
"These high-tech companies aim to keep their talented young employees at the office doing their job, not at home caring for babies," wrote Canadian bioethicist Francoise Baylis. "Facebook and Apple want a productive, not a reproductive, workforce."
As the ranks of healthy frozen-egg babies have grown worldwide, such naysaying has faded. Most studies show that the fertility-extending strategy is cost-effective — meaning there's a good chance of actually using the eggs, and a good chance they'll result in pregnancy — for women who freeze at age 37 or 38.
Gloria Bachmann, an obstetrician-gynecologist at Rutgers Robert Wood Johnson Medical School, said she believes it's high time that experts agree on how to advise women about social freezing. In a recent article in the Journal of Women's Health, she pointed out that counseling guidelines are well-established for cancer patients freezing their eggs, for older women using donated fresh eggs, and even for transgender people going from female to male.
Bachmann is particularly concerned that women freezing eggs may be unaware that the risks of pregnancy and childbirth increase with age.
If a woman uses her eggs at 45, "she may have hypertension, diabetes, issues with overall health because of her weight," Bachmann said. "She may not be the same individual she was when she froze the eggs."
The ASRM's new president, University of Pennsylvania infertility specialist Christos Coutifaris, favors updating the group's guidance to endorse social freezing, and agrees that doctors should explain the risks of childbearing in old age.
"But what is 'old'?" he added. "Is old 55? Or is it 40? I'm not that sure."
As with other reproductive technologies, egg freezing is forcing doctors, patients — and society — to ponder how old is too old to make a baby.
Back in 1996, when a 63-year-old woman gave birth using a young donor's fresh eggs, a medical journal editorial called it "ethically wrong and socially repugnant." But women who are just a few years into natural infertility, also known as menopause, present murkier issues. The ASRM's official opinion on fresh egg and embryo donation says it "should generally be discouraged over the age of 55," and clinics can ethically refuse to treat women with health problems that would endanger them or their offspring.
Still, that doesn't address the ethics and legality of turning away a postmenopausal woman from using her own long-frozen eggs.
And it doesn't address an inherent unfairness.
"There is a double standard," said Thomas Jefferson University psychologist Andrea M. Braverman, who counsels infertile couples. "Why aren't we jumping up and down about men who say, 'I'm ready at 48 or 49 to be a dad?' "
Holt, for one, doesn't intend to push the reproductive envelope very far. For her, having a baby is not so much a driving desire as a nice idea she is not ready to write off — not while friends work on "Operation Find Elizabeth a Wonderful, Eligible and Local Boyfriend Who May or May Not Want to Have Kids."