7 min read

If you can, you should freeze your eggs


  • you are in your twenties or early thirties,
  • you are a person who has periods and will go into menopause,
  • you have a good job with either fertility benefits or enough pay for you to cover costs out-of-pocket and
  • you can spend a few months in a city with a good fertility clinic,

I recommend you get your eggs frozen. Yes, even if you're in your early twenties. It's definitely an expensive process that is uncomfortable. But it's also cool technology. It will provide a lot of peace of mind if you know you want to have kids eventually, but not now. Even if it doesn't work out for you, you'll learn a decent amount about your natural fertility – I couldn't complete my egg-freezing cycle, but the information I learned from it was very valuable in planning my life and career.

As a society, we haven't figured out how to make female fertility less fickle. In an ideal world we would be able to create eggs from skin cells and gestate embryos in artificial wombs, bringing the human costs of pregnancy to zero. I hope that's the world my children and grandchildren live in, but it's not the one we live in today.

Today, if you don't have eggs frozen and you get ovarian cancer, or want to take testosterone, you lose the ability to have a natural child. Even absent catastrophic tail risks, it's nice to have a few eggs frozen – a friend of mine plans to have her first few children naturally, but wants to have the option to have more children after menopause.

The great thing is that we have the technology to help with this! It's not ideal, but it's also not terrible, and I think the trade-off is worthwhile for most women in developed countries who can pay the financial costs.

The rest of this post goes through how egg freezing works, what the process actually looks like, and how you can arrange it.

How does it work?

Let's start by recapping some facts about your period that you may or may not have learned in your 7th grade 'sex-ed' classes. (Yes, the ones where they separated the ovary-owners and the sperm-carriers into different rooms.)

  • When you're born with ovaries, you are also born with a prdetermined count of all the eggs you'll ever have.
  • This count is represented as your count of 'primordial follicles': follicles (like hair follicles) that will grow eggs when needed.
  • During a menstrual cycle:
    • Your body selects several follicles and has them grow eggs. This number might vary from 8-40.
    • One of those eggs is selected as the 'best' egg. When you ovulate, that egg is released into your uterus. The other egg candidates get trashed.
    • That one egg can become fertilized or not. If it isn't, it's expelled with your uterine lining: this is what causes monthly bleeding.

Egg freezing hijacks this process. Instead of disposing of those extra eggs, you take hormones that encourage them to grow. Then, once they've all grown, and just before you would normally ovulate, you take medication that encourages them to be released. Immediately after that, your surgeon goes and retrieves the eggs.

In more detail:

  1. The first step in any egg-freezing process is for you to get basic fertility testing. This usually looks like an ultrasound and a blood test.
    • The ultrasound will test for your antral follicle count (AFC), or how many 'mature' follicles a nurse can see on an ultrasound. This usually provides a good guide to how many eggs your doctor will be able to retrieve. Here's a guide to what different counts indicate. A pleasant side-effect of this ultrasound is that if you have endometriosis or any other issues, you'll be able to discover that too.
    • The blood test will tell you your anti-Mullerian hormone levels. This provides a guide to how many primordial follicles you have left. Here's a comprehensive guide to what different levels mean..
    • If these numbers are too low, this can indicate that you'll have problems stimulating enough eggs for egg retrieval to be worthwhile.
    • You can do this anywhere and at any time. If you're thinking of doing egg freezing, I'd recommend doing this as soon as possible. It'll give you a good indication of how many cycles you'll need to do.
  2. Then, you go on a course of drugs that your doctor recommends to stimulate your follicles. This will last around 2-3 weeks.
    • You'll need to be near your clinic for this, as this stage usually requires you to go in for an ultrasound two or three times a week. Nurses will monitor to make sure the drugs are working as expected and to make sure all the follicles are growing at the same speed. If they aren't, this is a likely place where your cycle will be 'cancelled.'
    • These drugs (known as FSH hormone) will cause all your follicles to develop eggs. This will cause your ovaries to feel heavy, and you might feel bloated. Doctors usually recommend that you avoid exercise or jumping, as you can cause a rare condition called ovarian torsion, where your ovaries twist and cut off blood flow to themselves.
    • These drugs are usually subcutaneous injectable drugs. Injections sound scary, but these aren't! They're administered with devices that look like pens, and the needles are incredibly thin. You stab yourself near the stomach, press a button, hold it there for a few seconds, then take it out. It's as painful as a pinch. Your nurses should demonstrate.
    • At the beginning, you'll likely take one injection a day. Towards the end, you'll need to take injections in the morning and evening.
  3. Finally, just before your body would naturally ovulate, you take a 'trigger' shot that prepares all the eggs to be released. Shortly after that (within 24 hours), your doctor retrieves all the eggs.
    • The mechanics of the surgery are pretty cool. Your doctor will stab a large needle into your ovaries through your vaginal wall. Using an ultrasound, she'll identify each egg and 'suck' them into the needle.
    • You're under general anesthesia for this. People describe it as pretty pleasant. However, you'll be very loopy and vulnerable afterward, and the clinic I used required you to have someone to pick you up. Recovery can be very painful and last several days, though some women don't have any pain.

As you can see, an egg-freezing cycle lines up nicely with a menstrual cycle, which is why it’s called a ‘cycle.’

You need 10-12 high-quality eggs to get an expected child. The number of eggs retrieved in one cycle varies a lot from person to person — from 8 to 40. (The early fertility testing can give you a guide to how many you’ll expect). Younger women tend to have more eggs, and those eggs tend to be of higher-quality. I found that doctors tend to be quite excited (and a little confused) if you do this while you’re in your early-to-mid twenties, as it’s pretty rare.

Depending on how many eggs you’re able to retrieve and how many children you want, you may need to do anywhere from 1-3 cycles. Most companies with fertility benefits will cover multiple cycles with a pre-defined cap.

Note that if you want to have the option for surrogacy, you need to do tests before egg retrieval! These are FDA-mandated in the United States. They're fairly simple tests, but your clinic may not pre-emptively tell you about them.

This LessWrong post has more details on how to increase the number of eggs you can harvest, and some guidance on where the best clinics are. (It claims to be about how to have polygenically screened children, but the best way to do that is to retrieve lots of eggs in an egg freezing/IVF cycle, so it's packed with useful information for us too!)

Why do I need 10 eggs to get an expected child?

The pipeline from egg retrieval to pregnancy is pretty abysmal. If you do the math, one cycle produces, in expectation, one kid – even if you retrieve 10 or 15 eggs!

The rough breakdown looks something like this (from here):

  • From 10 – 12 harvested eggs, 7 – 9 will be suitable for vitrification and storage.
  • Approximately 70-90% of the eggs will survive warming in the future.
  • Approximately 50-80% of surviving eggs will fertilize.
  • Approximately 50-90% of fertilized eggs will develop into embryos.
  • A single embryo will have a 20-35% chance of developing into a pregnancy.

The final pregnancy number sounds a bit low to me, but the estimated loss in the pipeline seems about right.

You can opt to freeze embryos instead of eggs. I've heard varying opinions on whether this increases your chance of success. It certainly reduces volatility, as you can realize the risk of having an embryo upfront and decide whether to do another egg-freezing cycle while you're still fertile. Obviously, it comes with other trade-offs.

How do I actually do this?

The price I have was told for each cycle is about $10-12k, though I’ve heard claims that it’s closer to $20k now. The cost is high, but many tech companies have fertility benefits that cover it completely for tech workers and their partners. (Google, notably, also provides surrogacy benefits). If your job doesn’t cover it, the price does put it out of reach for most people, but I think it’s worthwhile if you or your partner can afford it. I don’t know if it’s deductible or not.

If you can arrange for it to happen – especially if you are travelling to get your eggs frozen – it’s better to do it with some friends. That was what I did. It makes the process much more fun. You can have ‘first shot’ parties and compare experiences.

The quality of your clinic matters a lot. I used Spring Fertility in San Francisco, which was decent. They are also in New York. The experience is concierge-like, and many clinics will assign you a ‘case manager,' though the quality of this varies a lot (mine was sometimes hard to reach). A friend of mine had an excellent experience with Dr. Klatsky, who is in New York.

The clinics had fairly good availability when I tried talking with them. They were pretty happy to arrange for freezing/retrieval to happen during times that worked for me.

If you do end up freezing your eggs, let me know how it goes!