Social freezing: when your plans for a family are put on ice

Professor Leeners, if I were to freeze my eggs, where would they be stored?

They are frozen within seconds and stored in secure nitrogen tanks. Our tanks at the USZ are very secure: They are equipped with warning systems in the event of a power failure, fire and the technical department is on call day and night. This ensures that you can access your eggs when you need them. 

How long are frozen eggs stored?

In Switzerland, eggs are allowed to be stored for up to ten years.

Is the quality of the eggs affected if they are not defrosted until five or ten years later?

No. There are even some instances in America where frozen eggs have been used 30 years later. The ten-year rule is mainly a politically-motivated decision and less a medical one. 

Does social freezing make it possible to have children in your fifties or later?

First the good news: nowadays women are in much better health as they age. But it is of course important to have a check up before you try to conceive. If you are 45 or older, we perform a thorough assessment to determine how risky a pregnancy would be. 

But it is possible...

We are, of course, limited by our biology, despite all our efforts. The less fertile a women is, the more difficult it will be to collect any mature eggs. On average, one in six eggs will result in a pregnancy. Ideally, we take round fifteen eggs, but only mature ones can be used. It is virtually impossible to further mature eggs outside of the body. Not all eggs are mature when collected. This means most women need to do two rounds in order to collect enough mature eggs.

In other words, to become pregnant at 50, you need to have frozen your eggs at 40. Which, although not impossible, is also not entirely straightforward. And of course there are many risks associated with older mothers, for both them and their child, that would encourage pregnancy at a younger age.

When is the ideal time to consider social freezing?

A 25-year-old female has the highest chance of conceiving. Up to the age of 35, women still have a very high chance of conceiving. This is also the age at which most eggs are frozen. Women of this age start to think about their fertility. Most of the women that come to us are yet to find a suitable partner. More rarely they want to focus on their career without the worry of a ticking biological clock. They want to free themselves from the pressure of it being too late and make sure it is still possible to have children. 

Would you recommend the treatment to every woman?

Many worry about it beforehand, but once they know what it involves they tend to relax when they realise that the procedure is not very taxing on the body. The risks are more in relation to the pregnancy that might follow: are there, for example, any pre-existing conditions?

If a pregnancy is considered too dangerous, then social freezing is not recommended. Yet treatment involves effort and costs for something that might not even be used in the future.

Women should aim to live as healthily as they can during the stimulation phase. No smoking before and during treatment, checking medication carefully and drinking as little alcohol as possible: these are all factors that affect the quality of the eggs. 

What are the common side effects?

Virtually none. In the preparatory phase you may feel a little irritable and tired. The stimulation phase with injections is annoying but does not result in any real side effects. Hormones are produced by the maturing follicles themselves, which means they are natural hormones produced by the body. Hormone levels are higher as we let several eggs mature instead of just one, but are still a lot lower than during a pregnancy. 

What steps are taken if a woman decides to freeze their eggs?

The intensive phase lasts around two weeks, during which a woman attends three to five appointments. First we clarify whether they have any basic concerns, take bloods and perform a gynaecological examination. We also explain the process step by step.

The preparatory phase begins when a women has her period, during which she starts taking progesterone tablets. An ultrasound indicates how many follicles are in available during this cycle. This is followed by the stimulation phase which lasts around 9 to 13 days. The patient can inject themselves at home. During this time they have several ultrasound scans and the doctor will check how many follicles have reached maturity.

Egg retrieval is performed under general or local anaesthetic. The doctor is then able to see which eggs are mature and freezes them on the same day. Roughly fourteen days later the woman will experience bleeding and the process is complete. 

Do women experience pain during and after the procedure?

There may feel a little pain in their ovaries once the follicles have reached their maximum size. A normal ovary is 3-4 cm. The ovaries are significantly enlarged during this process, because multiple follicles are maturing at the same time. Some women may notice this. Sometimes bleeding can occur in the empty follicles during egg collection which, like bruises, can take a while to heal. Women can continue to go to work up until the day of the egg retrieval. We recommend avoiding any sport involving jerky movements for 1 – 2 weeks.

How much does social freezing cost? 

We estimate around CHF 4,000 to CHF 5,000 plus CHF 1,000 for medication. And implantation costs an additional CHF 2,000 to CHF 3,000. But you can fall back on your egg reserves and try several attempts.

Is it possible for a woman to notice her declining fertility herself? For example if she starts experiencing irregular periods?

No. If your period stops at 50, it has most likely been caused by the onset of menopause. But at 30, there are many reasons why periods may be irregular. Which is why I recommend finding out about your fertility early on.

What is your advice on social freezing and fertility?

I am all for women getting checked out at a young age. Unfortunately this approach is yet to be established in many medical practices. We know about the problem of early menopause and sadly see a lot of young women in our clinic affected by it, which is obviously a very bitter pill to swallow. This means egg donation is the only change of conceiving.

And in fact it is relatively easy to gauge a woman’s fertility by determining the levels of Anti-Müllerian hormone in the blood. This gives an indication of the egg reserve. Women in their 30s should check their fertility at least once and, depending on the results, at somewhat greater intervals. This is the only way to determine how many years of fertility you have left.

It’s perfectly fine if you don’t want to know. But some women may be grateful for the chance to still be able to do something about it and take the matter into their own hands.