Although embryo-freezing technology has been around since the 1980s, preserving an unfertilized egg was a technical challenge that most scientists didn’t think was worth tackling. In the late 1990s, however, researchers around the world found a way to freeze and thaw eggs without damaging them.
In the early 2000s, fertility doctors across the United States conducted clinical trials to replicate the method. By 2012, there was strong evidence that the procedure led to fertilization and pregnancy rates similar to IVF, convincing the American Society for Reproductive Medicine to stop deeming it an “experimental procedure”.
Without that label, insurers could cover the procedure, paving the way for tens of thousands of women to prolong their fertility by freezing their eggs. Nearly 20% of US companies with more than 20,000 employees offer egg freezing coverage, up from 6% in 2015, according to a national survey by Mercer, a corporate benefits consulting firm.
While egg freezing has become more popular over the past decade, the process can seem intense and exhausting. Here’s what you need to know.
What is egg freezing?
Women are usually born with around a million eggs, a number that steadily decreases with age. Oocyte cryopreservation, the technical term for egg freezing, is the procedure whereby eggs are harvested, frozen and stored for later use.
In preparation for egg retrieval, patients take hormones to stimulate the ovaries, causing them to develop multiple follicles (fluid-filled sacs that house an egg). When the follicles reach a certain size, a fertility specialist will remove the eggs, only freezing those that are ready to be fertilized. The whole process takes about two weeks.
How is the process?
First, fertility specialists perform a blood test to assess the patient’s current supply of eggs. They may also do an ultrasound scan to measure the follicles and ensure that the ovaries can be easily reached during egg retrieval.
Some doctors may advise the patient to take hormonal contraceptives before starting fertility medication, to increase the chances that the follicles will grow together at approximately the same size and rate. Fertility centers tend to have their own birth control preferences and policies, said Dr. Mindy Christianson, medical director of the Johns Hopkins Fertility Center.
Women undergoing the egg freezing process inject themselves with hormone medication once or twice a day. These injections, given over about eight to ten days, stimulate follicle growth.
Patients visit the doctor’s office every few days to measure these follicles and test for estrogen levels. The larger a follicle, the more likely it is to contain a mature egg, said Dr. Amanda Adeleye, a reproductive endocrinologist and assistant professor at the University of Chicago. Although a woman can have thousands of eggs, “most of them don’t respond to medication,” she said.
About a week after the process begins, patients are given drugs that block ovulation so that the eggs are not released before they can be retrieved. Then, when the follicles reach a certain size, patients give themselves a “trigger shot” injection, which releases the eggs in preparation for their collection, said Dr. Elliot Richards, director of reproductive endocrinology and infertility research at the Clinic. Cleveland.
About 35 hours after the trigger shot, doctors perform egg retrieval, draining each follicle by inserting a small needle into the vaginal wall and maneuvering it into the ovary.
The procedure typically takes between 15 and 30 minutes, said Dr. Rachel Ashby, director of the Egg Donor and Pregnancy Carrier Program at Brigham and Women’s Hospital. And the patient is usually sedated the entire time: “She doesn’t feel anything or remember anything,” Dr. Christianson said.
On that day, doctors can determine how many eggs have been retrieved. The average patient under age 38 can retrieve 10 to 20 per cycle, but this number varies depending on the individual’s egg supply and ovarian response to medication.
Only the mature eggs are frozen, using a process called vitrification: a type of flash freezing in which the eggs are bathed in liquid nitrogen to prevent ice crystals from forming, which could damage them. The eggs can then be kept in the center where they were vitrified or shipped elsewhere for long-term storage.
What are the risks of egg freezing?
As with any medical procedure, egg freezing has side effects and risks. Medication that stimulates the ovaries can increase a woman’s estrogen level 10 to 20 times that of a regular menstrual cycle, said Dr. Christianson.
Some patients experience mood swings as a result of higher than normal estrogen levels. And they may feel bloated as the ovaries enlarge due to the growth of multiple follicles.
If the patient has a history of blood clots, doctors may recommend an anticoagulant while she is on medication.
A few days before egg collection, many patients experience discomfort. “They’re not going to feel great,” Dr. Richards said. “It’s not something trivial.”
Bleeding and infection are risks with egg retrieval, but complications like these are not common, he added.
Due to the anesthesia used during the collection process, some people may experience nausea and vomiting, which will be treated with medication, Dr. Ashby said. Patients may also experience abdominal pain after recovery, which is usually managed with ibuprofen or Tylenol, said Dr Adeleye, adding that patients should take a day off work.
In rare cases, women can develop severe ovarian hyperstimulation syndrome, an adverse reaction to hormonal medications that stimulate egg production. The ovaries swell, causing small blood vessels to leak fluid, which can collect in the abdomen or, more rarely, around the lungs. Symptoms — which include swelling, nausea and difficulty urinating and breathing — most often occur three to five days after the procedure, said Dr. Adeleye.
The condition occurs in approximately 1% of women who undergo egg freezing and is more common in those with polycystic ovary syndrome because PCOS can increase the risk of developing too many follicles, which in turn can cause the syndrome. of ovarian hyperstimulation, said Dr Christianson.
Women who freeze their eggs at younger ages, in their 20s, are also at greater risk, said Dr Christianson, because higher egg counts are a risk factor for hyperstimulation. The more eggs a woman has, the greater the chance that the medication she takes before the egg collection will stimulate a large number of ovarian follicles.
Doctors can carefully monitor patients and reduce the risk of ovarian hyperstimulation syndrome, but anyone considering egg freezing should be informed about the risk of the condition, said Dr. Christianson.
How much does egg freezing cost?
Costs vary between fertility centers, but in general, a single egg freezing cycle, including ultrasound monitoring and medical supervision, can cost around $4,500 to $8,000. , said Dr Christianson. Patients typically complete one or two cycles, she added. Insurance coverage may vary depending on the patient’s type of health plan.
The injectable medication, separately, costs between $4,000 and $6,000 (R$20,360 to R$30,540) per cycle, she said, depending on how much medication a patient needs.
Storing the eggs comes at an additional cost, which can be upwards of $500 (R$2,500) a year.
Who is a candidate for egg freezing?
Egg freezing is no longer an experimental treatment, but neither is it a cure-all for fertility. A study of more than 500 women, published in the summer of 2022, found that the overall probability of births from frozen eggs was 39%. The findings also suggest that age and egg count contribute to success rates: if a woman was younger than 38 or thawed more than 20 eggs, her chances increased significantly. Guidelines from the American College of Obstetricians and Gynecologists state that there is not enough research to support egg freezing just to delay the birth of a child.
Some experts, however, said anyone at risk of age-related infertility could be a candidate. Other people who might seek out the procedure are those about to undergo chemotherapy, which can affect the ovaries, or people who identify as transgender or non-binary and are considering gender-affirming hormones, said Dr. Adeleye.
“The eggs that we retrieve today, technologically, are the best way we have to preserve your fertility,” said Dr Ashby. “But we won’t know if these eggs will work until they use them.”
Translated by Luiz Roberto M. Gonçalves
I have over 8 years of experience in the news industry. I have worked for various news websites and have also written for a few news agencies. I mostly cover healthcare news, but I am also interested in other topics such as politics, business, and entertainment. In my free time, I enjoy writing fiction and spending time with my family and friends.
