As an OB-GYN, I've talked to many women interested in egg freezing, a process by which you can have your eggs removed and frozen so they can be fertilized and implanted into your uterus at some point in the future.

Sometimes a woman wants to explore this option because chemotherapy or radiation treatment for cancer will damage her fertility, which is the main reason the procedure was developed 30 years ago. Other women consider egg freezing because they plan to have their ovaries removed to treat endometriosis. More and more, though, the women I talk to are considering egg freezing because they want to delay having a baby, and they want to increase their odds for success since they will be waiting until they are older, and therefore less fertile.

Age is the main factor affecting a woman's chances of getting pregnant. Women are most fertile in their 20s. When a woman hits 30, both the quality and number of eggs in the ovaries start to decline. Nonetheless, for a number of reasons - including career ambitions, a desire to put off marriage, access to contraceptives, and financial issues - many women don't feel ready to have a baby until they are 35 or older, the same age at which fertility drops. Egg freezing, also known as oocyte cryopreservation, can offer these women a chance to improve their chances of getting pregnant.

In 2012, the American Society for Reproductive Medicine issued new, broader guidelines for egg freezing, which previously had been categorized as experimental. Since then, the number of healthy young women who want to freeze their eggs for the sole purpose of having babies on their own schedules has skyrocketed. At the same time, a rapidly growing number of fertility clinics are busy marketing their egg-freezing services.

Being able to control the timing of having a baby can be a liberating thing if you're trying to balance a career and relationships with the desire to have a family. But, as with any medical procedures, egg freezing comes with risks and benefits. It's important to weigh those factors carefully before deciding whether to freeze your eggs.

Getting Ready

The procedure itself is a multistep process. First, you'll need to have an exam and blood work to determine your fertility level. After that, you can expect to undergo roughly eight to 12 days of hormone injections to stimulate your ovaries to produce more eggs. During this time, you'll need to have more blood work and transvaginal ultrasounds to monitor how your body reacts to the drug injections.

When your eggs are mature, a reproductive endocrinologist will remove them from your ovaries by inserting a needle through your vaginal wall. This procedure, done under twilight anesthesia, typically takes less than 30 minutes. After an embryologist examines the retrieved eggs, the ones that are deemed to be healthy and viable (usually around 80 percent) will be flash-frozen in liquid nitrogen. This method, known as vitrification, preserves eggs indefinitely.

It can take more than one cycle of egg retrieval, each of which must be preceded by the hormone injections, to get the optimal number of eggs. The fertility clinic my practice works with recommends freezing 15 to 20 mature eggs for women younger than 38. For women age 39 and 40, they recommend freezing 25 to 30 mature eggs. (For women over 40, not enough eggs are likely to be genetically normal for the procedure to be recommended.)

When you are ready to conceive, your eggs will be thawed and fertilized with sperm from your donor in the lab. These embryos can then be implanted into your uterus in a procedure that typically can be done in the doctor's office.

Financial Considerations and Chances of Success

Some insurance plans cover egg freezing when a woman has medical treatment that causes infertility, but many insurance companies do not cover elective egg freezing. Costs vary by clinic, but one cycle of egg retrieval can cost upward of $10,000, and many women require a second cycle. In addition, the cost of having the eggs thawed, fertilized and implanted can run into five digits.

As I often explain to patients, egg freezing does not guarantee success. The likelihood of success is largely driven by the number of frozen viable eggs and the age of the woman when she froze them. The clinic I work with estimates that women under the age of 38 who freeze the recommended number of eggs have a 70 to 80 percent chance of having a baby, while women over 38 have a 65 to 75 percent chance.

Younger women are more likely to have structurally and genetically-sound eggs. This does not mean, however, that women should automatically freeze their eggs in their 20s. The process requires a lot of time, money and effort, and if you're a woman with normal fertility, chances are good that you'd never need to use the frozen eggs anyway. In 2015, the University of North Carolina found that the optimal age for egg freezing - i.e., the age at which egg freezing made the biggest difference in the probability of eventually having a baby, compared with doing nothing at all - is 37.

Do Your Research

If you decide to freeze your eggs, it's critical that you find a clinic that has experience with both freezing and thawing eggs. Some clinics are experienced in only freezing them, but eggs can be damaged during thawing. Success rates among clinics vary considerably, so be sure to find one that provides data on their after-thaw egg survival rates, as well as their live birth rates. My message to patients who want to go down this path: do your research first!

Deciding whether or not to freeze your eggs is a complicated decision, one that might make you feel like you need a crystal ball. But as with any decision affecting your future, the best thing you can do is to gather all the facts and consider all the risks. It also helps to talk to your OB-GYN about your individual health history, fertility and personal circumstances.

To learn more about fertility treatments and egg freezing, read this American Society of Reproductive Medicine fact sheet.


Kristin Paccione, MD, is a board-certified obstetrician-gynecologist with the Mid-Atlantic Permanente Group. She sees patients at the Kaiser Permanente Largo Medical Center.