Freezing Your Eggs: 5 Things You Need to Know

When Eva Mendes gave birth to daughter Esmeralda last year, she was 40 years old—and no one batted an eyelash. After all, plenty of celebrities have had children later in life: Gwen Stefani was 44 when she welcomed her third son, Apollo, and Halle Berry was 46 when she became pregnant with her son, Maceo, in 2013.

Pregnancy success stories like these are wonderful. But they can make it easy to forget that our fertility decreases the older we get and that not all 40-something women are able to conceive. One way some women are trying to increase their odds, and beat the biological clock, is by freezing their eggs.

Egg freezing, also known as oocyte cryopreservation, is a fertility treatment in which a woman's mature eggs are harvested from her ovaries, frozen unfertilized, and stored for later use when she is ready to become pregnant. The beginning of the process is similar to in vitro fertilization (IVF) in that the patient undergoes four to six weeks of hormone injections prior to egg retrieval: generally, this involves two to four weeks of self-administered hormone injections and birth control pills to temporarily "turn off" natural hormones that produce one egg during a menstrual cycle, followed by 10 to 14 days of hormone injections to stimulate the ovaries and ripen multiple eggs. Once the eggs have matured, they are removed. The doctor inserts a thin ultrasound-guided needle through the vaginal opening and up to the ovaries. The procedure is done under moderate intravenous sedation and is not painful.

Immediately following retrieval, the eggs are analyzed for cryodamage and the healthy ones are frozen in liquid nitrogen containers and then stored—typically on-site in a lab at a fertility center, at a long-term storage facility, or at a frozen egg bank (depending on the center). Because the technology is so new, it's unknown how long frozen eggs can be stored for; some experts report as long as five years, while others say as many as 10.

When a woman is ready to have a baby, her eggs are rapidly thawed using warming solutions. As with IVF, they are then fertilized with sperm through a process called intracytoplasmic sperm injection (injecting a single sperm directly into each egg). The eggs are evaluated for three to five days and if they are determined to be fertilized and growing, they are transferred as embryos via a catheter to the woman's uterus.

Such a simple way to control your biological clock, right? Well, not exactly. If you're considering this option, you should keep the following in mind:

Locating clinics near you is easy: For a full list, just enter your state and zip code into the American Society of Reproductive Medicine (ASRM)'s online directory. Figuring out which fertility provider is right for you, on the other hand, is a little trickier.

Since clinics' performances vary considerably, women need to be educated on how to ask the right questions, says Michele Purcell, R.N., director of egg-freezing services at Shady Grove Fertility, which has offices in Maryland, Pennsylvania, Virginia, and Washington, D.C.

"It's not just about finding a center," she says. "It's about finding a center that does egg freezing and thaws the eggs and has data of its success rates. Technically, anyone can say that they can freeze eggs, but the question is: Are you freezing them correctly?"

Because eggs are fragile and sensitive to the freezing process, there's a real art to it, Purcell explains. Besides finding out whether the center is equipped to freeze eggs, ask specific questions about egg thaws and success rates. For example, how many eggs thaws have you done? What were the success rates with those thawed eggs? How many thawed eggs survived? What is the fertilization rate of those thawed eggs? What are your pregnancy rates per egg thaw?

"The worst thing that could happen," cautions Purcell, "is that a woman has this peace of mind [that her eggs are safe], but meanwhile they might not be frozen well and, as a result, might not survive the thaw."

In general, insurance coverage for costs associated with freezing your eggs remains spotty, though some providers may help foot the bill for some medications. Out-of-pocket expenses run around $7,500 to $12,500 for every egg-freezing cycle, between $2,800 and $5,000 for medication, and up to $800 per year to store the eggs. And sometimes, depending on a woman's age and the quality of her eggs, multiple rounds are needed to retrieve the recommended 10 to 30 eggs.

The upside? Many centers offer an initial consultation and fertility evaluation, which typically are covered by insurance. Often, this evaluation involves undergoing an ultrasound to check ovary function, checking hormone levels, talking to a physician, and other diagnostic testing. The visit is worth your while. "At least you'll have that information, and then you can be a better consumer to know if egg-freezing is right for you," Purcell says.

As with any new technology, there's little data to determine the success rates of egg freezing. For starters, the majority of people who have frozen their eggs have not yet had them thawed. In addition, there's no mechanism yet for the Centers for Disease Control and Prevention (CDC) or the Society for Assisted Reproductive Technologies (SART) to track the procedure's success rate. Though some clinics have achieved birth rates of 40 to 50 percent per egg thaw, sample sizes are small, and there may be some overconfidence about the outcome of using frozen eggs to have a baby, says Eric Widra, M.D., chair of SART's practice committee and medical director of Shady Grove Fertility.

"Believe me, I think it's a game-changing technology, and I'm super-enthusiastic about it, particularly for women who know they want children and want an insurance policy for the future," he says. "But to say that egg thawing is a perfectly well-established technology… it's a little hard to say that. I think we need to be honest and realistic with people about exactly how much we know."

Because of this critical lack of evidence, some medical experts do not endorse egg freezing "for the sole purpose of circumventing reproductive aging in healthy women." They believe it's a valid technique only for women who are medically indicated—in other words, who have to delay childbirth because of a cancer diagnosis or a family history of early menopause, for example.

Moreover, while the medical risks of egg-freezing itself are rare, the odds of pregnancy-related risks are higher among women of advanced reproductive age. Not only are women who become pregnant after 35 more likely to develop gestational diabetes, high blood pressure, and an increased risk of pregnancy loss, their babies are at a higher risk for chromosome abnormalities and being born premature. Although egg freezing is aggressively marketed as a way for women to delay childbirth, experts advise using it as a Plan B—not a Plan A.

Most fertility experts agree: The younger you are when you freeze your eggs, the better your odds of getting pregnant.

According to ASRM, egg freezing typically works best for women in their 20s and 30s and is not recommended for women over 38. Waiting until your late 30s or early 40s isn't ideal because the quality of your eggs isn't as high as when you're younger and you might have to do more rounds to increase your chances of having a good egg. "If it's something that you are thinking about," Purcell recommends, "it's better to do it when you have a higher fertility potential."

Despite her words of caution, many medical professionals, including Elizabeth Fino, M.D., an endocrinologist and fertility specialist at NYU Langone's Fertility Center in New York City, are confident that freezing eggs can psychologically benefit women and help them to feel empowered. "We've done self-reported studies, and results show that women who freeze their eggs do feel tremendous relief from societal pressures and have peace of mind," she said.