Freezing Eggs: 6 Scientific Facts You Should Know Before Opting In

Brigitte Adams became a champion of egg freezing (oocyte cryopreservation, in medical terms) when she appeared on the cover of Bloomberg Businessweek four years ago. The late 30s Vassar graduate’s picture was situated under the headline, “Freeze your eggs, Free your career.”

At age 45, she unfroze her eggs and selected a sperm donor. But the last of her frozen eggs failed to produce a pregnancy, Brigitte was heartbroken—and realized she needed a plan B.

Heralded as a marvel of reproductive medicine, egg freezing has become a popular trend among professional women. In fact, some employers, including Facebook and Apple, are helping their workers finance the procedure. But while freezing eggs has many benefits, and can seem like a way to stop a woman’s biological clock from ticking away—essentially a means of fertility preservation—the procedure may not necessarily be the godsend many women assume it is. Here are six realities of freezing your eggs you should know before you take the plunge.

According to The Washington Post, a woman who freezes 10 eggs at age 36—the average age women opt to have the procedure—has a 30 to 60 percent chance of having a baby with her frozen eggs later. A Brigham and Women's study published in Human Reproduction predicts a 70-90% success rate for women under 35 who freeze 10-20 eggs (success, in this case, means at least one live birth). 

Successful pregnancy rates depend on numerous factors, including the woman’s age (fertility starts to decline around age 35) and the quality of the sperm used to fertilize the eggs.

While many women cite their lack of a partner and their biological clock as the primary reasons to freeze eggs, others choose to do so for other reasons.

Some cancer treatments and other medical issues may damage the ovaries or cause premature menopause. Women who have these illnesses may elect to have their eggs frozen to increase the odds that they may have children after their medical treatments.

Many women opt to freeze their eggs for professional reasons. They may choose to focus on their careers and delay having children until later.

 The egg retrieval process is the same as the first phase of in vitro fertilization. Women receive powerful hormone injections that stimulate the ovaries to produce multiple eggs. You’ll need to undergo numerous blood tests and ultrasounds along with the injections for weeks before the retrieval.

After one or two weeks, the egg retrieval process is initiated. The doctor will push a needle through the vagina to the ovarian follicle, and a suction device attached to the end of the needle will remove the eggs. Most women are under mild anesthesia for the procedure.

The unfertilized eggs are them taken to a lab and undergo the freezing process, in which they are cooled to subzero temperatures for storage.

There is a small risk of infection, and some women may experience ovarian hyperstimulation syndrome (OHSS), in which they have a strong reaction to the hormone treatments and their ovaries become swollen. Many women who experience ovarian hyperstimulation syndrome have only a mild reaction, but others may experience nausea, vomiting, and abdominal pain. In rare cases, it can lead to kidney failure, blood clots, or even death.

The hormone shots can cause different reactions in different women. Some may experience mood swings, irritability, or bloating, while others may have no responses.

A single freezing cycle usually costs between $5,000-8,000, according to Money magazine. Doctors usually recommend that you undergo two cycles. And that’s not the end of the process.

When you’re ready to use your frozen eggs, you’ll need to have them fertilized for in-vitro fertilization. IVF can cost upwards of $10,000.

Insurance is unlikely to cover the procedures, since the procedure is considered elective, unless treatment for a medication disease or condition like cancer may render her infertile.

Many women know that the likelihood of chromosomal abnormalities climbs as they get older. There’s also a higher risk of miscarriage and birth defects, as well as disorders that can make it more difficult for them to conceive.

The best time to freeze eggs, medically speaking, is in your late 20s or early 30s, since your fertility (egg production) starts to decline when your reach 35. That doesn’t mean a woman over 40 can’t get pregnant, but it does mean she might need to go through more cycles than a younger woman, and her chances of having a successful pregnancy decline.

Given the cost and risks involved in freezing eggs, woman in their 20s may choose to wait a few years before making the decision to undergo the hormone therapies and freezing process. Still, to maximize your chances of becoming pregnant, it’s best to freeze your eggs by the age of 35.

Frozen embryos are more viable than frozen unfertilized eggs, so if you have a partner now, you may want to have your eggs mixed with your partner’s sperm and freeze the embryos to increase your likelihood of a resulting pregnancy. This will also save you a step in the process—after thawing the frozen embryos, you will be able to undergo in-vitro fertilization right away.

Brigitte’s story has a happy ending. She underwent IVF again, now with a donor egg and donor sperm. Her baby is due in May.

While freezing your eggs can give you back some time, act as a source of fertility preservation, and serve as a stress and anxiety reliever, it’s important to review all the risks, information, and success rates before undergoing the procedure. Weigh the pros and cons, and understand that there’s no guarantee involved in the process.