Egg freezing: When should you freeze your eggs?

What is egg freezing?

Egg freezing, also known as oocyte cryopreservation, is a type of fertility preservation treatment. In short, you’re given hormone injections to stimulate the ovaries so more eggs mature compared to a normal menstrual cycle, and the eggs are then extracted, frozen, and stored. When you’re ready to use them, the eggs are fertilized in a lab, and the embryos are later implanted into the uterus (in the same way as during conventional IVF). 

Egg freezing can be done for medical reasons, for example, before undergoing a treatment that can impact fertility. However, it’s also become an increasingly popular procedure in recent years to prolong our fertile years so that we can potentially have children later in life [1]. This is sometimes referred to as “social” or “elective” egg freezing.

When should you freeze your eggs?

As always, we all have our different fertility journeys. Because egg freezing is a personal choice, it’s hard to give a one-size-fits-all answer to the question of when it’s best to do it. However, one very simplified way of answering it is: if you know you want to freeze your eggs, it’s best to do it sooner rather than later. 

At this time, there hasn’t been enough research done to give specific guidelines on exactly at what age you should freeze your eggs. That being said, it’s important to know that age does impact fertility, and studies into egg freezing have shown that outcomes are better if eggs are frozen at a younger age [2]. Even with that in mind, there’s no guarantee that the outcome will be successful — and that’s important to understand too.

Our mid-thirties seem to be a point of reference, though — this is generally when the age-related fertility decline picks up speed. One study looking at outcomes after egg freezing cycles found the chances of giving birth were better if the eggs were frozen before the age of 35 [3]. Another study found a sort of “threshold” with markedly better outcomes for eggs that were frozen at a younger age when comparing eggs frozen before and after the age of 38 [4].

When it comes to freezing your eggs, timing matters. According to Dr. Natalie Crawford, a fertility expert and member of the Natural Cycles Medical Advisory Board, earlier is generally better.

“The take-home message as it relates to your eggs: the sooner the better,” she says. Dr. Crawford explains that “for most, the ideal age to freeze your eggs is around age 32 to 33 years if you are not ready to conceive. At this time, egg quality and egg quantity are still relatively high, which can lead to better outcomes."

But the decision is highly individual. As Dr. Crawford notes, “your own individual goals — how many kids you want and when you might be ready to start trying to conceive — will impact what age will be the best for you.”

Her final word of advice? “If you know having a family is a life goal, consider freezing your eggs when you are young in order to keep as many options open as possible.”

Why does age impact fertility?

Most people are probably aware that fertility is linked to age, and that it becomes more difficult to get pregnant as we get older. But it’s probably less known why that is, and when these changes happen. You may have guessed it — it has to do with our eggs.

We’re born with all the eggs we’re ever going to have, and this collection of eggs is called our ovarian reserve. Common estimates are that we’re born with around 1–2 million eggs, and our ovarian reserve will shrink starting from the moment we’re born until we reach menopause [5]. Broken out, it looks roughly like this:

• Birth: 1–2 million eggs
• Puberty starts: 3–500,000 eggs left
• Age 37: 25,000 eggs left
• Menopause: 1000 eggs left [6]

Aside from the number of eggs in our ovarian reserve, the quality of the eggs is another aspect. Some eggs will naturally have genetic changes that mean they either can’t be fertilized or won’t result in a healthy pregnancy, and as we get older, we’ll have fewer of the high-quality eggs left in our ovarian reserve [7].

We’re generally the most fertile in our twenties and early thirties, so if egg freezing is something you’re thinking about — and you have the option — this may be a good time to consider it. It’s also a good idea to discuss it with your healthcare provider — they can help you understand what timing would be best for you.

Other circumstances that can impact the decision to freeze your eggs

Age isn’t the only factor to take into account when it comes to freezing your eggs — there are several other reasons you might consider this option. 

• Illness: If you have a medical condition or need to undergo a treatment that can affect your fertility, you may consider freezing your eggs to preserve your fertility. This can be the case for certain cancer treatments, like chemotherapy. Make sure to check with your doctor about what options are available for you.
• Partner: We all know that finding the right partner isn’t always the easiest, and research has found that this is a common reason for choosing to freeze eggs [8]. Egg freezing can offer some extra time to find the one to spend your life with, so there’s less stress to jump into a relationship.
• Career: Another common reason for egg freezing cited in research is wanting more time to build one’s career before having children [8]. Since women still take on much of the burden at home, along with the physical experience of pregnancy and postpartum recovery, this is something that can impact the timing of when you want to have kids. Again, egg freezing offers the possibility of delaying starting a family until you’re ready in your career.
• Economy: Other socioeconomic factors also come into play when it comes to our decision to start a family. Being financially stable is an important factor for many before starting a family, and this can also impact the decision to freeze your eggs [8]. On the other hand, egg freezing itself can be expensive, so it’s not a possibility for everyone.

Everyone has their own fertility journey, and that includes decisions around fertility preservation treatments like egg freezing. It’s also worth considering that you’ll need to go through IVF if you decide to use the eggs later, and that can be a challenging process itself. That’s why it’s always a good idea to discuss with your doctor if you’re thinking about freezing your eggs — they can help you figure out if this is the right option for you.

How does the egg freezing process work?

The egg freezing process usually takes around two to three weeks to complete [1], and there are a few different steps involved. Let’s go through what you can expect.

1. Taking medication to stimulate the ovaries

You’ll be given hormone injections that you can take yourself at home (or with help from someone you trust), and you’ll also go to regular scans at your clinic to check on the progress. In most cases, you’ll take the injections for around two weeks [9]. They contain a hormone called follicle stimulation hormone (FSH), which works by stimulating your ovaries so that more eggs mature than in a typical menstrual cycle [10].

In some egg freezing protocols, you’ll need to take medications to stop the ovaries from releasing eggs for a couple of weeks before you start the stimulation [10]. Make sure you discuss with your doctor which protocol would work best for you.

2. Extracting the eggs 

When the eggs are mature, it’s time to extract them. This is done by your doctor at a clinic. You’ll be put under general anesthesia or sedation for the procedure, which takes about 30-60 minutes. Your doctor will insert a small tube into your vagina which contains a needle, and that’s used to extract the mature eggs from the follicles [11]. 

So, how many eggs are collected? Usually, it’s somewhere around 7-14 eggs per egg retrieval if you’re under the age of 38 [1], but this number will ultimately depend on how many eggs there are. Your doctor will let you know after the procedure how many eggs were extracted.

3. Freezing the eggs

Once the eggs are extracted, they are frozen using a technique called vitrification. Essentially, this means that the eggs are cooled really quickly to freezing temperatures, and that’s done to ensure that as many as possible are preserved when thawing [9]. The eggs are then stored until you’re ready to use them.

Are there any side effects from egg freezing?

Because you’re given hormones to stimulate your ovaries during the egg freezing cycle, it’s possible you’ll experience some side effects. For most people, these are mild and they should go away once you stop the injections. You might notice: 

• Breast tenderness
• Bloating
• Feeling nauseous 
• Headaches
• Mood swings [10, 12]

There’s also a small risk of ovarian hyperstimulation syndrome, which is quite rare but can lead to more serious symptoms that require treatment, like blood clots, stomach pain, shortness of breath, or dehydration [12]. If you experience any symptoms or feel unwell after the procedure, always reach out to your doctor to be sure.

How long do the frozen eggs last?

The eggs are stored in liquid nitrogen tanks at extremely low temperatures. There isn’t really any time limit for how long they will last, so in theory, they can be stored indefinitely. However, you should check with your clinic how long they will store your eggs for, since this can vary depending on where you live and what your contract says. 

Things to consider before freezing your eggs

So, is there anything you should keep in mind before starting the egg freezing process? First off, it’s always best to get in touch with a healthcare professional who can give you personalized advice. However, here are some things you can consider doing: 

• Check your ovarian reserve: There are some tests that you can do to get a better understanding of how many eggs you have in your ovarian reserve, which can be helpful if you’re thinking about freezing your eggs. An AMH-test (which measures the levels of Anti-Müllerian hormone in your blood) is often used as an estimate of how many eggs you have left, as well as how you would respond to fertility treatment [13].

• Stop hormonal birth control: Because hormonal birth control generally works by inhibiting ovulation, you can’t use it during the egg freezing process. You may even need to come off your birth control some time before starting the egg freezing protocol, so make sure to check with your doctor so you can plan ahead. Keep in mind that you’ll still need to use protection, such as condoms, to prevent pregnancy.

• Maintain healthy habits: Age is the main factor that will impact our eggs, but it’s always good to maintain healthy habits, too. Research into this area is fairly limited, but maintaining a healthy weight and diet, exercising regularly, not smoking, limiting alcohol, and managing stress levels can all be beneficial for fertility [14].

• Consider the cost: Egg freezing can be expensive, and unfortunately, it’s not an option for everyone. The cost of the treatment can vary depending on where you live and what type of insurance you have, so it’s good to do some research ahead of time to understand how much you’d need to pay. If you have a medical condition, you may be able to get the treatment covered, so make sure to check with your provider.

What happens when you want to use the eggs?

If you decide to use your frozen eggs, you’ll go through IVF. The process will look very similar to “regular” IVF — the main difference is that you’ll use your frozen eggs instead of extracting new ones during the IVF cycle. 

The frozen eggs will be thawed and fertilized with sperm in a lab using a process called intracytoplasmic sperm injection (ICSI), which means that one sperm is injected into each egg [1]. The resulting embryo or embryos will then be inserted into your uterus.

What are the chances of getting pregnant using frozen eggs?

It’s important to know that egg freezing isn’t a guarantee that you’ll become pregnant if you do decide to use your eggs. Estimates of the chances of success for IVF treatment with frozen eggs will vary depending on several factors, mainly your age, when and how the eggs were frozen, and how many eggs were extracted during the egg freezing process. 

Success rates can be measured in different ways, but let’s look at a successful treatment as one resulting in the live birth of a baby. An estimate supported by research is that the success rate for those who come back to use their frozen eggs is around 30%. This means that roughly a third of embryos from frozen eggs result in a baby after they are inserted into the uterus [15]. Research also shows that the birth rate increases a bit if 15 or more eggs are frozen [16].

Broken down further, here are some stats for egg freezing based on a small study of 27 women who returned to use their frozen eggs:

• 74% of eggs survive the thawing after having been frozen
• 67% of those eggs become fertilized on average
• 48% of embryo transfers result in pregnancy
• 35% of embryo transfers result in birth [16]

It’s also worth keeping in mind that egg freezing is still relatively new, and techniques are still advancing, which means that success rates vary for different people and clinics. More research is also needed in this area, as studies that look at the success of these treatments are often based on a relatively small number of women, and that makes it more difficult to make general statements. If you’re looking into freezing your eggs, make sure to check what the success rates look like for your age group at your clinic.  

Take control of your fertility journey with Natural Cycles

Everyone has their own unique fertility journey, and here at Natural Cycles, we believe that understanding your body and fertility empowers you to make informed decisions about your reproductive health. The NC° app isn’t just a hormone-free and FDA Cleared birth control method and fertility tracker that uses your body temperature to pinpoint ovulation — it also allows you to better understand your body through personalized insights about your menstrual cycle. Why not see if Natural Cycles could be right for you today?