When was the first time you learned about your “eggs”?

Perhaps it was when you first learned about what a period is. Your ovaries release one egg (or “ovum”) per month, and when it goes unfertilized your period begins. But how much information do you have on what these eggs (or “ova”) are and how they relate to our bodies? And what is all this conversation about egg freezing, anyway?

As a biological female, we are born with all of the eggs we will ever have. That’s roughly 2 million eggs. Throughout our lives, hundreds of follicles — or our “egg sacs,” but we’ll come back to this later — are lost each month. You may be asking yourself, why? And that’s a great question. All of our cells have a predetermined life cycle. Just as other cells in our bodies die off as part of the natural process of aging, so do the egg cells that we don’t use each month during ovulation.  

Interestingly, the rate at which we lose our follicles varies from person to person, and increases in our mid-to-late 30’s. If the rate of loss is occurring faster at a younger age, this will lead to menopause at an earlier age. But who’s to know the rate at which we’re losing our ovarian follicles? This isn’t something you can calculate based on how often you exercise, or how healthily (or unhealthily) you eat. So how can we figure this out?

Various methods have been developed to better understand our ovarian reserve, or the quantity of our eggs. Two key determinants of the reserve are the Anti-Mullerian Hormone (AMH) or the Antral Follicle Count (AFC). Think of AFC as the number of follicles that are between 2-10mm and visible in the ovaries. This will be a good predictor of our overall remaining follicle pool.

What about if I have a low AFC or AMH count?

This can predict early menopause. It can also be used to estimate how sensitive we’ll be to hormonal stimulation, and the number of oocytes likely to be retrieved.

Remember the “biological clock”? The reason that is referenced in relation to when we choose to conceive (should we decide to) is because our age is intimately linked to both our egg quantity and quality. So as we get older, not only do we literally have less eggs present in our bodies, but the quality of those remaining eggs are compromised and more likely to have chromosomal abnormalities. For example, by age 40, the majority of our remaining eggs will be considered “abnormal” in quality. This is why older age is proportionately linked to decreased pregnancy rates and increased miscarriage rates.

But what can we do?

Of course we can’t stop ourselves from getting older — yet. However, there are steps we can take to first inform ourselves about our fertility health and then inform our life decisions going forward.

So should I be freezing my eggs then?

Maybe you’re a go-getter business-woman with no plans to slow down in sight. Or maybe you’re not in the place to be getting pregnant. But we all deserve the time and best quality options to figure it out when we’re ready. This is neither unusual nor wrong — it’s your life after all. But let’s take a look through what egg freezing might look like for you.

What is egg freezing after all?

Egg freezing is the process of stimulating your follicles. Remember we spoke about the “egg sacs” earlier? Your follicles actually contain the egg cell. Egg freezing utilizes hormone injections to encourage your follicles to produce and mature as many eggs as they can. Once these eggs have been produced, a reproductive endocrinologist (REI) retrieves these matured eggs using a thin needle that goes through the wall of the vagina into the ovary. These eggs are microscopic so the procedure isn’t invasive. After retrieval, the eggs are immediately frozen using “vitrification,” aka quick freeze. And guess what? When these eggs are frozen, they’ll stay that way for what’s suspected to be hundreds of years…or until you’re ready to use them. Whichever comes first. However, because pregnancy complications increase with advanced age, the American Society for Reproductive Medicine (ASRM) guidelines require eggs to be used by the age of 55.

How many eggs is the “right” amount?

This answer is unique to each one of us, and is determined after considering multiple factors — i.e. cost, time, side effects, and the chance of success in the future. But to create a highly generalized idea — women with normal ovarian reserve under the age of 40 should be able to attain a range of 10-20 eggs in a cycle. You’ll actually be able to use a calculator to estimate your chance of a successful pregnancy with a certain number of eggs at any given age. We have the exact calendar you’d need to figure this out!

What will the egg freezing process look like from end to end?

First things first, you’ll start with a fertility assessment. This is when we determine your AMH levels, your visible follicle count (using a vaginal ultrasound), and consider your family and medical history. We’ll create a catered plan just for you — because each of us is so unique we want to ensure your plan is custom fit to your needs. Then we identify the hormone injections and medications necessary to promote as many healthy, mature eggs as possible.

We’ll teach you how to administer the medication at home on your own. Yes, you can totally do this! All in, the process takes about 10-14 days to complete. This is where the “time” consideration comes in. We want to choose the time that works best for you and your life. For individuals with irregular periods, or a very tight schedule, we might recommend birth control to help time your cycle properly. 

When it’s time to start stimulation you will come in for a baseline ultrasound to make sure your ovaries are ready to begin the process. You’ll start the hormone injections and then come back a few days later for another ultrasound. We monitor you closely during this process and adjust your medications as needed. You will usually come back every 1-3 days for repeat ultrasounds and blood tests. During this time, you should avoid vigorous exercise. And you can use us as an excuse to get some well-deserved rest and relaxation. 

After about 8-12 days of injections, your ovaries should be ready for the egg retrieval. You will do a “trigger shot” to get the eggs ready, and come for the retrieval 35 hours later. The retrieval is done with sedation and takes about 10-15 minutes. Using a thin needle, the retrieval takes place through the vaginal wall into your ovaries. As soon as you recover from the anesthesia, you will be able to go home with a companion. You may feel a little bloated and crampy for a few days. Most women are back at work the following day. You should get a period 2 weeks later and should be completely back to normal by then.

Dr. Lynn Westphal
Dr. Lynn Westphal
Dr. Lynn Marie Westphal, M.D., FACOG, and Kindbody's Chief Medical Officer graduated summa cum laude from Lawrence University, earned her M.D. degree at Stanford University, and did her residency training in obstetrics and gynecology at UCLA and Stanford University. She did a fellowship in molecular biology at Stanford University and completed her fellowship in Reproductive Endocrinology and Infertility (REI) at UCSF. Dr. Westphal joined the full-time faculty at Stanford University in 1998 and was a Professor in the Department of Gynecology and Obstetrics, Director of the Fertility Preservation Program, Director of the Third Party Reproduction Program, and Director of the REI Fellowship. Her interest in fertility preservation for cancer survivors led her to set up one of the first oocyte cryopreservation programs in the country. She has held numerous national leadership positions and was the President of the Fertility Preservation Special Interest Group of the American Society of Reproductive Medicine from 2008-2009. She was the Director of Women’s Health at Stanford from 2005-2012. In 2012, she co-founded the Stanford Center for Health Research on Women and Sex Differences in Medicine (WSDM) and served as co-director of the program for two years.