Is egg freezing the answer to age-related fertility decline?

Chapter 8 of my book is about egg freezing.

The method of freezing eggs has really improved over the last 15 years. By freezing eggs when she is in her 20s or 30s, a woman can, in theory, extend her fertility. So, is egg freezing the answer to reduce the effects of age-related fertility decline?

How we freeze eggs

Freezing cells and tissues involves preservation for extended periods of time at sub-zero temperatures. There are several methods of freezing cells and tissues. All use cryoprotective additives, special chemicals that reduce damage by preventing ice formation and cooling until sub-zero temperatures are reached. Usually frozen cells and tissues are stored in liquid nitrogen which has a temperature of -196°C.

What happens to a woman when she goes through egg freezing?

If a woman has decided to opt for egg freezing, or is thinking about having her eggs frozen, she needs to visit a fertility clinic. The process she will go through is almost identical to the first half of an IVF cycle, but without the fertilisation part, so no embryos are made.

One cycle of egg freezing takes about 2-4 weeks. A woman will be given fertility drugs so multiple eggs grow and can be collected. All women respond very individually to fertility drugs. It is routine for IVF clinics to check a woman’s ovarian reserve to determine the dose of fertility drugs that they will give, to reduce the risk of hyperstimulation, and to optimise the number of eggs collected. When the fertility drugs are given, the woman will be monitored by ultrasound and maybe some blood tests to check how the eggs are developing.

When she is ready, the IVF clinic will collect the eggs, using a minor surgical procedure which should take about 30 mins. This is identical to the IVF egg collection. Briefly, she will be given light sedation, and a vaginal ultrasound probe will be used to visualise the ovaries. A needle will be pushed through the vaginal wall towards the ovary where it will be used to aspirate the follicles and hopefully collect one egg from each follicle. All the collected eggs will be taken to the embryology laboratory and those that are at the right stage will be frozen. The operation is usually a day case.

How many eggs to bank and the success of egg freezing

There is no easy answer to the questions of how many eggs to bank, and what the success rates are. Success will depend on the age of the woman when she froze her eggs, and how many she has frozen. To gain accurate data, we would need hundreds of women across all ages to use their frozen eggs. But few women who have frozen their eggs have come back to use them, so at the moment we do not have reliable data. And it is not just about the number of eggs banked; the quality is important as well. As a woman gets older, more eggs will have abnormalities. A younger woman who has 20 eggs banked will most likely have more viable eggs than a women who is aged 40 with 20 eggs banked.

Costs and regulations

Egg freezing is certainly not cheap. In the UK, one cycle will cost in the range of £3-5000. It is common to undergo more than one cycle to increase the number of eggs in the bank. And there are also storage costs and a fee when they are used. Some countries, such as the UK, also have rules about how long eggs can be frozen. In the UK, there is currently a 10 year storage limit.

Why do women want to freeze their eggs?

Are women freezing their eggs to intentionally postpone motherhood because they are not ready; or because they are ready, but they do not have a partner, or their partner is not willing?

The vast majority of women who freeze their eggs are single (in most studies this is 90% of women who freeze their eggs), highly-educated, financially secure and ready to start a family, if they could only find a suitable partner. Some women are worried about rushing into an unwise relationship. Freezing eggs gives women more time to try to find Mr/Ms Right, rather than rush into a relationship with Mr/Ms Second Best. Some of those women who have a partner freeze their eggs to take the pressure off their relationship. These women are usually older than the ideal age to freeze eggs, with the majority being over 35.

Other reasons why eggs are frozen

Eggs may be frozen because the woman is about to have treatment that may cause the eggs to die, such as chemo or radiotherapy, for women with a disorder that might affect her eggs, such as Turners syndrome or endometriosis, for people undergoing gender reassignment, during an IVF cycle when there is no sperm available on the day and for egg banking for women who are not responding well to treatment.

Egg freezing is also used for egg donation cycles. Before the use of egg freezing, donor and recipient cycles had to be synchronised using hormones. Now that egg freezing is successful, some clinics are performing donor/recipient cycles using frozen donor eggs. By freezing the eggs, they can be transferred to any country in the world and used whenever the recipient is ready.

Joyce Harpers latest book,  Your Fertile Years, will be published in April 2021, by Sheldon Press.

Read more
Your Fertile Years is available to pre-order on Amazon now. Contact joyce.harper@ucl.ac.uk if you would like Joyce to give a talk to any group or at any event.

Blogs
Chapter 1: Knowing Your Body; Understanding Your Menstrual Cycle And Fertile Window
Chapter 2: The biological clock, female fertility decline
Chapter 3: Optimising your reproductive health
Chapter 4: Everything you should know about sex
Chapter 5: If you do not want to become pregnant, how do you prevent it?
Chapter 6: How Can Sexually Transmitted Infections Affect Fertility?
Chapter 7: What you should know about pregnancy and childbirth

And videos to accompany the blogs on my YouTube Channel
Why I wrote Your Fertile Years
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8

9 things you should know if you want kids in the future