A Behind-the-Scenes Look at Egg-Freezing Technology

If you're in your peak reproductive years, but not in the headspace (or literal space) to start a family, you're in good company: Many women in their 20s and early 30s are putting off pregnancy to focus on work, play or just surviving the uncertainty that has accompanied COVID-19.

With pandemic-associated job losses and fewer opportunities for singles to pair up, egg freezing may seem like a viable option to preserve your fertility. But just how often do these frozen eggs become a bundle of joy? It's tricky.

We asked Jaime Hogerty, PhD, embryologist and lab director at MU Health Care's Reproductive Health and Fertility Center, for a behind-the-scenes look at egg freezing. With expertise in biomedical sciences, she is responsible for freezing, thawing and fertilizing eggs as well as preserving embryos.

What is Egg Freezing?

Formally known as "oocyte cryopreservation," or OC, egg freezing requires you to inject ovary-stimulating medication to produce as many mature eggs (oocytes) as possible for retrieval and storage. Doctors retrieve eggs through an ultrasound-guided procedure, then freeze and store them (called cryobanking) until you're ready to conceive. When that day dawns, experts thaw your eggs, fertilize them with your partner's (or donor's) sperm and transfer one or multiple embryo(s) into the uterus during an in-vitro fertilization (IVF) cycle.

Who is the ideal egg-freezing candidate?

Egg freezing was once reserved for women undergoing cancer treatment, or those whose fertility was compromised because of endometriosis, polycystic ovarian syndrome (PCOS) or early menopause. But it’s also an option for women who aren't ready to get pregnant now but want to improve their odds of having a biologically related baby down the line. The idea is to tap into your fertility before it starts to wane.

When should you freeze your eggs?

The reality is younger women usually have better eggs. So, it's best to freeze your eggs during your 20s and early 30s when your fertility and egg quality are at their peak. Doctors generally advise women to freeze their eggs before age 35.

What's the egg-freezing process like?

To freeze your eggs, you'll have to go through the same hormone injection process that you would for in-vitro fertilization. It looks something like this:

• At the start of your menstrual cycle, injectable hormones will stimulate your ovaries to produce as many eggs as possible (as opposed to the one mature egg you typically produce each month).
• Doctors monitor egg development with ultrasounds and blood tests.
• Once your egg follicles mature, doctors retrieve them through a transvaginal procedure.
• Immediately after retrieval, embryologists flash-freeze, or vitrify, your eggs and store them until you're ready to become pregnant.

How long can the eggs remain frozen?

We don’t yet have clear data about just how long you can safely store frozen eggs. The benefits and risks of long-term oocyte storage will emerge with time and use of OC. So far, it seems that you can probably store oocytes for many years, just like embryos. The only hiccup: You have to pay an annual storage fee to keep those eggs frozen.

How much will egg freezing cost me?

Freezing your eggs isn't cheap. While prices vary from clinic to clinic, you can expect to spend somewhere in the neighborhood of $8,000 to $15,000 just for egg retrieval and initial OC. And some women have to repeat the cycle to produce enough eggs for banking purposes (though you can freeze as few eggs as you like). Then there's the cost of storing frozen eggs, which can run up to $1,000 per year.

Will insurance cover egg freezing costs?

Most insurance policies do not cover egg freezing. Women at high risk of early menopause, or those who are undergoing treatment for cancer, may have more luck getting some of their costs covered.

What are the side effects of hormone injections?

Side effects are generally mild, and include headaches, nausea, breast tenderness and irritability. About 5% of women develop something called ovarian hyperstimulation syndrome (OHSS) when the hormone injections designed to stimulate the ovaries work a little too well. You may notice signs like nausea, abdominal pain, bloating and diarrhea. Doctors check for signs of OHSS during the monitoring period and can adjust medication doses as needed.

What are the side effects of the egg retrieval process?

The retrieval process is minimally invasive and takes only about 20 minutes. Afterward, you may feel some cramping, but it typically resolves within a day or two. In very rare cases, women may experience bleeding, infection or bowel and bladder damage. The ovarian stimulating and egg retrieval process can also be emotionally taxing, in part due to changing hormone levels. And although knowing you have eggs stored can provide hope and assurance, there's no guarantee you'll be able to conceive with your frozen eggs.

How often do frozen eggs become a healthy baby?

It's tough to say. Surprisingly, many women who freeze their eggs don't come back to use them because they attempt and achieve pregnancy without needing to use their cryopreserved eggs or decide against baby-making entirely. Because few women have used their frozen eggs to date, data regarding success rates are lacking. However, studies do suggest that embryos created using previously frozen eggs are as likely to implant and become healthy babies after embryo transfer as embryos created from fresh eggs. The chance of becoming pregnant after embryo transfer is roughly 30% to 60%, depending on your age when eggs were retrieved and the quality of the sperm used to create the embryos.

The Bottom Line

Concerned you won't be in your reproductive prime when you're ready to have a baby? Consider meeting with a reproductive endocrinologist to get a complete workup. Not every woman who wants to become a mother has a seamless path to pregnancy. But if you have a clear picture of your egg quality, quantity and ovarian function, you'll be better equipped to make informed decisions.

Next Steps and Useful Resources

• Learn more about in vitro fertilization (IVF)