Egg freezing is a controversial issue in reproductive medicine because only relatively recently have fertility centers been able to reliably freeze eggs unlike sperm, which we have been freezing for decades.
Egg freezing may find usefulness for women about to undergo cancer treatments that would otherwise destroy all their eggs. The technique may also be useful for women who realize that their fertility declines with age (see my Reproductive Aging page) and they do not find that the time is right for a pregnancy, for any number of reasons. They are interested in banking their fertility. I should also point out that this concept is largely not applicable to men (with the exception of cancer treatment).
Rachel Lehmann-Haupt was 37 when she froze her eggs, a process technically known as oocyte cryopreservation. She knew it wouldn’t guarantee her fertility. But the San Francisco-based writer had just ended a relationship and knew she wanted kids.
“I wanted to buy biological time,” says Lehmann-Haupt, who’s now 40 and still childless. “The older I get, the more I think, ‘Maybe the eggs I froze will be my route to motherhood.”
As women increasingly delay childbearing until their 30s or 40s, many are discovering the biological clock waits for no one.
Women lose much of their natural fertility between 35 and 40, according to Dr Nicole Noyes, co-director of the Oocyte Cryopreservation programme at the New York University fertility centre and Lehmann-Haupt’s doctor. As women age, the quality of their eggs also decreases, which increases the chance of miscarrying, Noyes says.
Though women can’t make their eggs healthier, they can keep them from getting older through egg freezing. The process, which takes between two to six weeks, involves taking fertility medication to mature multiple eggs in the ovaries. Once ready, the eggs are extracted from the woman, gently dehydrated and stored in liquid nitrogen. When a woman is ready to become pregnant, her eggs can be thawed, fertilised and transferred to the uterus as embryos.
For women whose medical treatments present a risk of infertility, particularly cancer patients, egg freezing is a promising way to protect the possibility of a pregnancy. More controversially, the procedure is also marketed as an option for healthy women who aren’t ready to have children but hope to in the future.
Critics emphasise that the best chance of having a baby is doing it naturally when a woman is younger than 35. They worry that egg preservation will give a woman false confidence, that she may make plans based on preserved eggs that fail in the future.
But Noyes says this isn’t what’s happening. “They’re 36, 37 years old, and they’re panicking,” she says. New York City’s Lucia Vazquez, who froze her eggs at age 32, explains it like this: “I’m not waiting to have kids because I have frozen eggs. I’m waiting to have kids so I froze my eggs.”
One concern is that egg freezing is still in the early stages and the oocytes can be damaged during the freezing and thawing process. The American Society for Reproductive Medicine calls it “experimental” and warns that until there’s more “proven scientific information”, healthy women shouldn’t use it as a way to defer reproductive ageing.
“The dilemma is that the potential to put off the biologic clock is intoxicatingly empowering for many women struggling with the profession vs biology conundrum,” says Kentucky fertility expert and ob-gyn Dr Rebecca Booth.
About half of fertility clinics offer egg freezing, says Glenn Schattman, associate professor of reproductive medicine at Cornell University’s Weil Medical College in New York, and a co-author of the ASRM guidelines. There is no national registry tracking the number of pregnancies derived from previously frozen oocytes, but a 2009 study showed 936 babies had been born from frozen eggs worldwide, with no increase in birth defects.
In theory, the eggs may be stored indefinitely, but shelf life is difficult to determine. And no one knows how freezing the egg affects the long-term health of the baby.
It’s also expensive. Though prices vary by clinic, it costs about US 9,500 (Bt306,000) to freeze eggs. A private company may have an additional charge of 1,000 to 3,000, Noyes says. The thaw cycle – when the eggs are taken out of liquid nitrogen and fertilised – is around 3,500 to 5,000. “Some clinics are greedy and charge 12,000 for the freeze,” says Noyes. “Buyer beware: Higher prices do not equate to a better clinic.”
Still, egg freezing can take the pressure off for some women.
Lehmann-Haupt, who wrote “In Her Own Sweet Time: Unexpected Adventures in Finding Love, Commitment and Motherhood” about her experience, remains hopeful.
But if her own eggs fail? “I think I’m slightly in denial,” she admits. “I’d be pretty devastated if I can’t have a child or adopt.”