Thinking about egg freezing? Here's what you need to know

Egg freezing is a great fertility preservation option for women who want to have children one day, but not any time soon. And considering that women over 40 now have a higher rate than ever before, it's clear that we're delaying motherhood until a bit later in life.

'Fertility declines naturally with age from about 32 years,' writes Dr Anita Mitra in her book The Gynae Geek. This is due not only to a decrease in the quantity of eggs, but also in their quality.

'That's not to say that everyone over the age of 32 will struggle to get pregnant – or vice versa; being on the pill for a decade, for example, doesn't mean you're saving eggs – of course, it's a nice idea, but unfortunately using contraception that stops ovulation doesn't prevent the number of eggs from declining at the same rate.'

That's where egg freezing comes in; you're preserving the life of these eggs to be used at a later date. So, what do you need to know? Read on for the expert lowdown.

What is egg freezing?

'Egg freezing technologies, or cryopreservation, was originally developed for young women wishing to save some eggs prior to undergoing cancer treatment that could attack the ovaries resulting in early menopause,' Dr Anita explains in her book.

'Nowadays, many of us take longer to settle down and become financially stable enough to start a family, so use these technologies as a way of delaying motherhood – referred to as "social egg freezing" – has garnered much interest.'

Before starting the process – which takes around two to three weeks start to finish – you'll be tested for any infectious diseases. The Human Fertilisation & Embryology Authority explains that this doesn't affect whether or not you can freeze your eggs, only how they will be stored to avoid potential contamination of other samples.

You'll then probably have to take drugs to boost egg production and enhance their maturity. Once ready, they're then collected under general anaesthetic, usually around 15 depending on the number of eggs the woman has.

A solution is then added to the eggs to protect them before freezing; they are then stored in tanks of liquid nitrogen.

When is the best time to freeze your eggs?

The short answer is not too late, but not too early either. 'If you already have very low egg stocks, it might not work or you may get very few eggs to store, which is why it's advised to undergo the treatment in your twenties or early to mid-thirties at the latest,' Anita writes.

'It has been suggested that the highest chance of a successful pregnancy can be achieved when freezing eggs before 34 years of age. Equally, that doesn't mean that after 34 you've left it too late. Unlike a chicken breast, the time in the freezer doesn't affect the quality of the eggs/embyros.

'However, you're currently allowed to store eggs or embryos for a maximum of 10 years in the UK, so you also don't want to do it too early. If you didn't use the eggs they could be donated for research, training or also for another woman to use.'

Benefits of egg freezing

Older eggs come with more associated risks, such as higher chance of miscarriage or chromosomal abnormalities like Down's syndrome.

'By freezing your eggs, you stop the egg ageing clock a the point at which they go into the freezer,' writes Dr Anita. 'So if you freeze your eggs at 30 and use them at 40, your risk of miscarriage and genetic abnormalities is the same as a 30-year-old's.'

How much does egg freezing cost?

'Social egg freezing' as it's referred to is not available on the NHS, meaning you'll need to self-fund if you're considering the process.

According to the Human Fertilisation Embryology Authority's website: 'The average cost of having your eggs collected and frozen is £3,350, with medication being an added £500-£1,500. Storage costs are extra and tend to be between £125 and £350 per year. Make sure you get a full costed treatment plan from your clinic so you're not caught out by unexpected "extras".

'Thawing eggs and transferring them to the womb costs an average of £2,500. So, the whole process for egg freezing and thawing costs an average of £7,000-£8,000.'

Does egg freezing affect fertility?

'No. Although the medications stimulate lots of eggs to develop, this is similar to what happens naturally every month; it just makes it more efficient, rather than using up the eggs quicker,' writes Dr Anita. 'It hasn't been shown to hasten the menopause.

'Do remember that it's still a relatively new procedure in healthy women, having been used more extensively in women at risk of undergoing premature menopause.

'We don't yet truly know whether there are any long term risks due to the small number of women who have used this type of treatment.'

Anita's quotes are all taken from her book The Gynae Geek: Your No-Nonsense Guide To 'Down-There' Healthcare with her permission