Skip to main content

Press release: Age is the key factor for egg freezing success says new HFEA report, as overall treatment numbers remain low

Egg freezing is rapidly emerging as a viable clinical technique to preserve women’s fertility, as long as the eggs are frozen at a clinically optimum age, a new report from the Human Fertilisation and Embryology Authority (HFEA) reveals today.

But with just 178 women having treatment using their own thawed eggs in 2016 – and with only an 18% birth rate - there is some way to go before egg freezing can be seen as a common practice.

In 2016, there were 1,310 egg freezing cycles, equivalent to just 1.5% of all fertility treatment cycles performed that year. Nevertheless, this represents a 17% increase in the number of freezing cycles from 2015, a doubling since 2013, and a 460% increase from 2010, when only 234 freezing cycles were carried out. Such rapid growth indicates a rise in both awareness of, and appetite for, freezing eggs for later use, and coincides with the emergence of improved clinical techniques such as the fast-freezing “vitrification” method.

However, there are fewer egg thawing treatment cycles than egg freezing cycles, suggesting that although more women are freezing their eggs, many of them have not yet made a decision to try for a pregnancy. In 2016, there were just 519 egg thawing cycles across the UK, up from 448 in 2015 (+16%). Of these only 35%  involved the patient’s own eggs, with 65% using frozen donor eggs. The report shows that although the birth rate for women using their own eggs in a thaw cycle has increased from 12% in 2014 to around 18% in 2016 – it is still significantly below that for IVF overall (26%). In 2016, 39 babies were born to women using their own thawed eggs in treatment.

Importantly, the data shows that while a woman’s age at thaw has relatively little impact on a woman’s chances of success, the age at freeze does, with evidence showing that if eggs are frozen below the age of 35, the chances of success will be higher than the natural conception rate as the woman gets older.

However, the report also shows that the most common age of women freezing their own eggs for treatment is 38, with some women freezing their own eggs into their 40s. This suggests more work must be done across the UK fertility sector to establish best practice for freezing and thawing treatments. It is important patients are aware of the risks of pregnancies later in life, and that clinics act responsibly when advising patients of their treatment options. Where women over the age of 40 are freezing their own eggs, the likelihood of a future pregnancy is very slim and we would caution against this being a sensible option for this group of women.

Sally Cheshire CBE, Chair of the HFEA, said women should be cautiously optimistic about egg freezing techniques, and that we must ensure women are fully informed about what to expect:

“The rapid growth in egg freezing since 2010 shows how much potential this technique may have for altering the way people plan their future families and it is a positive story for those women undergoing medical treatment which may seriously affect their fertility. Our data shows, however, that egg freezing cycles and subsequent thawing still account for only 1-2% of all IVF treatment cycles, and even fewer result in a baby being born. 

“It is so important that women undergoing any type of fertility treatment are fully aware of the risks and cost involved, and the real possibility of it being successful. Currently women using their own frozen eggs in treatment have a success rate of 18% (30% with frozen donor eggs), which offers no guarantee of achieving a successful pregnancy and birth. Clinics have an ethical responsibility to be clear that egg freezing below the age of 35 offers women their best chance of creating their much longed for family.”

Download the full report.


The report also covers a range of other topics:

Medical freezing:

Freezing for medical reasons is a primary reason for egg preservation. Women undergoing medical treatment, such as chemotherapy, may want to preserve their eggs for use post-treatment. Only women freezing or thawing eggs for medical reasons will be eligible for NHS funding. In 2016 NHS funded freeze cycles accounted for just under a fifth of the total (19%), with 50 ‘medical’ thaw treatment cycles performed. Increases in success rates using own eggs, while still below that of fresh IVF, offer hope to patients who need to freeze their eggs due to medical reasons.

Cycles using frozen donor eggs:

Egg thaw treatment cycles using frozen donor eggs have significantly higher success rates than for patients using their own eggs. The birth rate per treatment cycle from all cycles using frozen donor eggs in 2016 was around 30%. This is in line with the overall birth rate from IVF which was 26% in 2016 (and in line with the birth rate for fresh donor eggs which was 33% in 2016). The most common age for women using thawed donor eggs is higher than for women using their own eggs, at 43-45 years.

The report shows that egg thaw treatment cycles using frozen donor eggs have significantly higher success rates than for patients using their own eggs, and that while the birth rate with frozen donor eggs is 30% per treatment cycle, it is 18% for a patient’s own eggs. The higher success rates for donor eggs compared to own eggs is to be expected, and is largely due to the access criteria applied to women who donate their eggs. This access criteria requires women to have healthy indications for fertility, such as BMI, age and lifestyle factors.


The majority of women freezing eggs using NHS funding are aged below 35, with 89% below age 38. In 2016, 81% of all egg freezing cycles were privately funded and 19% publicly funded. This has changed from 74% private and 26% public in 2010.


In 2016 most women freezing eggs are registered with a male partner (53%), or no partner (46%), with a minority registered with a female partner (around 1%). Women who have frozen their eggs are much more likely to have no partner compared to standard IVF treatment (46% compared to 2%).

Most women using frozen eggs in a thaw treatment cycle are registered with a male partner (91% in 2016), which is similar to IVF overall. There was a higher proportion of patients registered with no partner at 8% compared with IVF overall which was only 2%. There is no significant difference in partner status between women using frozen donor eggs and their own frozen eggs in treatment.

Number of clinics performing egg freezing:

The number of clinics performing one or more egg freezing cycles has increased from 37 in 2010 to 62 in 2016. However, most clinics are performing 10 or fewer cycles a year (64% in 2016), with only 15% performing more than 20 in 2016. Just three clinics performed more than 100 egg freezing cycles with the highest performing 186 cycles.

This shows that a large concentration of egg freezing cycles are being undertaken in a limited number of clinics despite many offering the treatment. This means that despite media interest in egg freezing, most clinics do very few cycles of egg freezing each year, and only a select few do a lot of egg freezing cycles.

As with standard IVF treatment, the majority of cycles take place in England, particularly in London. However, this is the case disproportionately so for egg freezing, in which the bulk are primarily located in London (78% of egg freezing cycles take place in London, as compared with 36% of all fertility cycles).


A review of prices advertised on UK clinic websites in May 2018 showed that the average cost of a complete egg freezing cycle, including storage and use of eggs in future treatment ranges from £7,000-£8,000. This is made up of the cost of egg freezing, storage and using frozen eggs in treatment. Prices range from £2,720-£3,920 for an egg freezing cycle, with the average (median) cost for freezing eggs being around £3,350. There are variations in what is included within this cost, with most clinics including one or two years of storage, however these costs do not include the medication required for treatment which can vary from £500 to thousands. The cost of storing eggs also ranges from £125-£350 a year.

When it comes to using frozen eggs in treatment, costs range from £1,650-£4000, with the average (median) being around £2,500. Freezing eggs is therefore a significant investment and, as with all fertility treatment, clinics should inform patients of all the relevant costs upfront so they have an accurate idea of how much the full process is likely to be.

Ten year storage limit:

Although the clinically optimum time to freeze eggs is early on in a woman’s reproductive life, success rates are not the only consideration, and other factors may lead women to consider freezing their eggs later in life. In some cases, one reason is because the younger a woman is when she freezes her eggs, the less likely she will to ever need to use them, because she could probably conceive naturally.

Conversely, if a woman freezes her eggs in her late thirties, when her fertility is already in decline, the process may be more invasive and expensive, more cycles may be needed to collect the preferred number of eggs, and the birth rate will be lower, but she is more likely to return to use her frozen eggs.

One reason women may consider freezing eggs later than the clinically optimum time is the 10 year legal storage limit for frozen eggs. This storage limit could mean that the end of the storage period arrives before the woman is ready to use her eggs, and the woman may need to choose between allowing her eggs to perish or using her eggs in an IVF treatment thaw cycle before she feels ready.

Any change in the 10 year storage limit would be a matter for Parliament, but as the Regulator we have heard the voice of many in the sector calling for a review of the current arrangements.                 

Sally Cheshire added:

“The report is also clear that the younger you freeze your eggs, the greater chance of your success. This will inevitably lead to further calls for a change in the law to increase the current ten year storage limit for frozen eggs.

“Any change in that limit can only be introduced by Parliament, but we know that many in the sector are calling for such change. As the report highlights, the issue is not as straightforward as it may at first seem, but it is one we aim to be well engaged with.”


Publication date: 20 December 2018

Review date: 20 December 2020