The concept of egg freezing seems simple: A woman gives herself hormones to produce more eggs than she ordinarily would. A doctor retrieves those eggs and stores them in a lab for later use.
Actually, the science — as well as the emotional and physical commitments — are much more complicated.
"Social" egg freezing, or elective egg freezing, is a procedure that has been steadily growing for the last decade. According to the most recent data from the American Society for Reproductive Medicine, 6,207 women had their eggs frozen in 2015, up from 475 women in 2009. That number is expected to rise as more companies, like Apple and Facebook, provide coverage for the process.
More women are having kids later in life, according to recent data from the Centers for Disease Control and Prevention, which could also be a factor.
"It's a great procedure," said Dr. Daniel Shapiro, the medical director for Reproductive Biology Associates in Atlanta, Georgia. "If my daughters are in a situation where they aren't quite ready to family build, I would have them do it."
Why are more women freezing their eggs?
There are at least three main reasons:
- A woman wants children, but not now, either because of life pressures or because the right partner hasn’t come along.
- A woman in her late 20s or early 30s has been diagnosed with endometriosis or polycystic ovary syndrome and wants to preserve her eggs until she’s ready to try for a pregnancy.
- A woman is about to undergo fertility-damaging cancer treatment.
Critics say egg freezing gives women a "false hope" of delaying pregnancy. It can also be extremely expensive.
The price varies from clinic to clinic and from woman to woman — based on her health insurance coverage and how much medication she needs. A recent study published in the Reproductive Biomedicine & Society Online found that out-of-pocket expenses ranged from $1,000 to $18,000 per cycle. The average cost per cycle was close to $7,000. Some women need to go through more than one cycle.
If you're thinking about freezing your eggs, here is a step-by-step guide of what to expect.
Best age to freeze your eggs
"Peak fertility for women is at age 27," said Shapiro. "And then your fertility starts to slowly decline ... The decline is subtle but measurable."
However, women are advised not to freeze their eggs in their early 20s, but to wait until their late 20s to early 30s.
"You could potentially be investing in something you won't need," said Dr. Joshua U. Klein, the medical director of Extend Fertility, an egg freezing clinic located in New York City.
The first step: a 'fertility assessment'
A fertility specialist or an OB-GYN will evaluate a woman's ovarian reserve, or current egg supply. Women are born with their lifetime supply of eggs, usually in the millions, and there are two markers that specialists can use to gauge a woman's current supply and how she will respond to fertility medications.
The first tool is a blood test to analyze a woman's anti-mullerian hormone which is produced by the current egg supply. The more eggs you have, the more that hormone is produced and secreted in the blood.
The second assessment is a pelvic ultrasound to review a woman's antral follicle count; that is, the number of follicles remaining in the ovaries. Antral follicles are a measure of future egg supply.
Once a specialist reviews these two factors, they can determine an individualized treatment plan for the patient.
"It's important to clarify that they are not measures of egg quality or a woman's fertility potential," explained Shapiro. "They are measures of how women will respond to fertility drugs. There is no good test of fertility potential, unless you've been pregnant before."
Next: a lot of shots
Once a woman decides to move forward, she'll have to learn how to administer several shots daily to stimulate egg production. The medications are follicle-stimulating and luteinizing hormones.
A woman will start these medications when she starts her menstrual cycle, and will inject the hormones once or twice a day for eight to 11 days, on average. These medications are not typically covered by insurance and can cost between $2,000 to $4,000, according to Extend Fertility.
About halfway through the cycle a woman will add another daily medication that prevents her body from ovulating early and releasing the eggs before the retrieval surgery.
The final shot is referred to as the "trigger shot," which initiates the final egg maturation before the retrieval and freezing take place. It must be taken 36 hours before the procedure.
"Most people actually feel OK with the medication," said Klein.
But a minority will experience some temporary side effects, including:
- mood symptoms
- hormone swings
There are more serious side effects, too: Ovarian hyperstimulation syndrome can occur if the body makes too many eggs at once and can lead to fluid accumulation in your abdomen. This is one reason why doctors monitor women through every step of the process. During the eight to 11 days of hormone shots, a woman will typically be monitored by a fertility specialist every other day.
"During these appointments, we can see activated follicles, how many and how big they are, how they are growing and how many (eggs) are growing," Klein explained. "The blood work helps us evaluate the hormones; estrogen increases as the follicles grow."
At last, surgery.
The procedure involves doctors inserting a needle through the vagina, into the sedated patient's ovary to drain the egg bubbles, said Klein.
It takes about 10 minutes to retrieve the eggs. There are no scars or incisions, though a woman might be sore following the procedure. About 20 minutes later, the embryology team determines how many eggs were retrieved.
This is not a final number — not all eggs that are retrieved are mature enough to freeze.
"So, for example, if you got 15 eggs in an egg freezing cycle, you might have 11, 12, 13 or 14 that are freezable mature ones, and one to four that are not," Klein noted.
You need a lot of eggs.
How many eggs should a woman freeze? The short answer: as many as possible.
"We ask women, 'what is your goal?'" Shapiro said. "Are they trying to engineer a whole family, or just provide a back-up plan for one baby if they can't get pregnant on their own."
The older you are when the eggs are retrieved, the more eggs you'll need for one baby, Shapiro explained.
You will lose eggs in the thawing process.
For the eggs that do survive thawing, some won't fertilize. And for the eggs that are fertilized, not all will become viable embryos. And once a woman becomes pregnant with an embryo, there is still a risk of miscarriage, as there would be in any other pregnancy.
"Biology is messy, and eggs drop out because they're not good ones," Klein elaborated. "We're trying our best to recreate nature and it is inefficient... Freeze as many (eggs) as you can."
Extend Fertility encourages women to freeze at least 12 eggs, which could take more than one cycle. Reproductive Biology Associates helps women decide on what number they'd like to reach, but the minimum count they'd be satisfied with, for their youngest patient — 30 or younger — is six to 10 eggs.
Two researchers, Dr. Janis H. Fox, a reproductive endocrinologist at the Center for Infertility and Reproductive Surgery at Brigham and Women's Hospital, and Dr. Randi Goldman, a clinical fellow at Brigham and Women's Hospital in Boston, developed a mathematical counseling tool to help doctors and patients figure out how many eggs a woman would need to meet her reproductive goals.
To use the tool, enter the age at which you're having your eggs frozen and a "goal" number of eggs you'd like to freeze. The probability results reveal one, two or three live births.
"Everyone is surprised at how many eggs they need for whatever goal they've set for themselves," said Goldman, who hopes this tool can help to eliminate that element of surprise.
How are they frozen?
Immediately after retrieval, the eggs are passed to embryologists who clean the eggs and determine which ones are mature. Only mature eggs will be frozen. Water molecules are removed from the mature eggs and replaced with cryprotectant. Next, eggs are submerged into liquid nitrogen to prevent ice crystals from forming.
They're stored in canisters that maintain the temperature. The tanks are monitored closely, with alarm systems in place for any temperature or liquid nitrogen changes. Eggs can be stored indefinitely — for a fee. Price ranges depending on the facility, but expect to pay about $400-$1,000 per year.
By now, you've likely read a horror story or two: Eggs were lost or destroyed in transit, from one clinic to another. Or most recently, two tank malfunctions in Ohio and California led to the possible destruction of eggs for hundreds of families.
Choosing the right facility to store eggs requires some research. Here are some questions to ask and things to be aware of before making a decision.
No matter how many eggs you freeze, it's not a guarantee.
There are some statistics that can help women make an informed decision about the process.
- A 2016 study indicated that women who froze 10 eggs before age 35 saw a 60 percent chance of a successful pregnancy.
- The same study found that women who froze 15 eggs (before age 35) saw an 85 percent chance of a successful pregnancy.
- Women who froze their eggs at age 36 or later saw a 36 percent chance for a successful pregnancy, after freezing 11 eggs.
Bottom line, if it's something you're thinking about, talk to your doctor.
"Every woman deserves that conversation, or the opportunity to have that conversation," explained Dr. Bat-Sheva Lerner Maslow, a reproductive endocrinologist at Extend Fertility. "Nothing pains me more than women learning too late that they've missed their opportunity to have the family that they desired."