Egg freezing — how it works and why age matters

October 10, 2018
By Rachel Grumman Bender

Egg freezing is on the rise in the U.S. The method helps preserve a woman’s eggs, which can then be thawed, fertilized with sperm in a lab, and implanted via in-vitro fertilization (IVF) at a later date.

Not that long ago, egg freezing, also known as oocyte cryopreservation, was considered an “experimental” procedure. But in late 2012, that changed when the American Society for Reproductive Medicine and the Society for Assisted Reproductive Technology announced they would no longer deem the procedure experimental, according to an article in the Canadian Medical Association Journal.

“Over the past 10 years, egg freezing has really become mainstream,” Jaime Knopman, MD, director of fertility preservation at CCRM New York, tells Yahoo Lifestyle. Knopman points out that about 475 women froze their eggs in 2009, while more than 6,000 women had the procedure in 2015, according to data from the Society of Assisted Reproductive Technology.

Although women have a variety of personal reasons for wanting to delay childbirth, a July 2018 study — one of the largest of its kind so far — found that, contrary to popular belief, women aren’t necessarily freezing their eggs so they can pursue their career or education. Instead, it’s often the “lack of a stable partner” who is committed to marriage and parenting that is the biggest influencer, according to the study authors.

If you’re considering freezing your eggs or are just curious about it, here’s what you need to know: First and foremost, the procedure is expensive, costing about $10,000 per egg-freezing cycle.

When a woman decides to freeze her eggs, the first step is usually a conversation with her physician. “We talk about her gynecologic history, her family history, her medical history, followed by an exam, which includes a transvaginal ultrasound as well as hormone levels,” explains Knopman. “This is then followed by bloodwork. The bloodwork includes hormones, which are done to measure the quantity of eggs remaining in a woman’s ovaries.”

For women who are good candidates for egg freezing, the next step is hormonal injections. These are shots that women typically give themselves twice a day — once in the morning, once at night — for 10 to 12 days, so you need to be comfortable with needles. “We will teach you how to give yourself the shots,” Knopman notes.

During that period, women see their physician every two or three days for bloodwork and ultrasounds. “The point of the bloodwork and the ultrasound is to make sure that your ovaries are responding appropriately to the medication,” she explains. “Most women feel totally fine, if not pretty awesome, on the hormones because your estrogen levels go up.”

Once eggs have matured and are ready to be removed by a physician, Knopman says the target number that doctors usually aim to retrieve and freeze is 12.

But age is a big influencer — in fact, Knopman says it’s the most important factor. “So if I’m sitting with a 42-year-old who’s freezing her eggs, I’m going to want way more than 12 because most of those eggs are not going to be normal,” says Knopman. “But if I’m sitting with a 32-year-old who freezes 12 eggs, I feel much more confident that, within one of those eggs, we’ll have a viable, good-quality embryo.”

Knopman adds: “The younger you are when you freeze your eggs, the better your eggs are going to do.”

According to the Mayo Clinic, about 90 percent of eggs survive the freezing and thawing process, and about 75 percent will be successfully fertilized. However, that doesn’t guarantee a pregnancy. The chances of becoming pregnant after a fertilized egg is implanted in a woman’s uterus are about 30 to 60 percent, according to the Mayo Clinic, depending on the woman’s age when she first froze her eggs.