Six patients from London Women’s Clinic who chose to preserve their fertility through egg freezing have had not just one baby as a result of their treatment but have now gone on to have another and all from their first round of egg collection for fertility preservation. Egg freezing ambitions need not be limited to just one baby.

As is the case in many aspects of fertility care today, the key to their success lies in the revolutionary techniques of freezing, not just to preserve the viability of eggs but also to safely store embryos for use in a later transfer cycle. Embryo freezing has become such a routine part of fertility treatments that frozen embryo transfers are now almost as common as fresh, having increased in number by 18% from 2019 to 2021, according to official figures from the UK regulator, Human Fertilisation and Embryology Authority (HFEA).

The six London Women's Clinic cases were in a range of single and partnered women who all opted to freeze their eggs in their 30s, the oldest at 38. All returned to thaw and fertilise the collected eggs between two and 13 years later, and all gave birth to a healthy baby - at ages between 31 and 43. After their initial egg freezing, crucial to their family plans was having a number of surplus healthy embryos in freeze storage.

And a few years later, all six had these frozen embryos thawed and transferred in a further pregnancy attempt. So far, five of the six have had a second healthy birth, with the sixth in the midst of an ongoing pregnancy with a live birth due very soon. Just as significantly, three of the six still have more embryos in storage, with the possibility of a further transfer and pregnancy, if so desired. And all from just one cycle of egg collection to preserve fertility.

The six examples illustrate how ‘egg freezing technology is now fulfilling its promises’, says LWC Scientific and Managing Director Dr Kamal Ahuja.

A 2019 study of egg-freezing patients at London Women's Clinic, found several reasons why women choose to freeze their eggs. 'What we are seeing as we study the age, relationship status, and time taken between freezing and thawing, is the individual autonomy exercised by women in these matters,’ says Dr Ahuja. The examples of the six women going on to have a second child also demonstrate the success which egg freezing can potentially bring to women. ‘Women who put their faith in egg freezing at centres with proven experience like London Women's Clinic have good reason to do so,’ says Dr Ahuja.

Experience at London Women’s Clinic, which has seen an ever-escalating number of women opting for egg freezing, suggests that the latest treatment figures released by the HFEA (for 2021) are running behind the reality of everyday progress. While the HFEA described egg freezing as ‘one of the fastest growing fertility treatments in the UK,’ its caveat that ‘very few patients come back to use their eggs’, or that egg freezing success is unusual, is not reflected in our present data. The most recent results involving frozen donor eggs at London Egg Bank support other international studies showing that the viability of frozen eggs is comparable to that found with fresh, and that in most cases freezing has negligible impact on an egg’s viability.

The HFEA, however, has correctly emphasised the age effect in freezing eggs, noting that results - as in all fertility treatments - will be better in women who freeze their eggs before the age of 35. It’s the age at which the eggs are frozen which matters, not the age at which the patient returns to thaw and use her eggs.

One interesting observation in the six women having second babies from their initial treatment is that after thawing, three of them had their resulting embryos screened for chromosomal abnormalities before being frozen again. After this ‘double freezing’, embryos found to be chromosomally normal - through a technique known as PGT-A - were available for thawing and transfer later on.

‘It is a biological fact that the risk of miscarriage or an embryo’s failure to implant in the uterus increases with age, and that this is largely because of increasing chromosomal complications in the embryo’ says Balsam Al-Hashimi, Deputy Embryology Manager and PGT lead at London Women’s Clinic. The three patients who elected to have PGT-A were all successful in their second embryo transfer, with frozen embryos from frozen-thawed eggs which had been screened and shown to be free of any chromosomal abnormality.

Similarly, in our larger series of egg-freezing cases at London Women’s Clinic, the selective use of PGT-A doubled the cumulative live birth rate (from 28% to 57%) when compared to transferring embryos not tested for chromosomal balance.

Considering egg freezing success rates when selecting a clinic for treatment is an important first step. Our egg freezing success rates page can be a useful tool for making these decisions.

Alternatively, if you’d like to speak to a member of our egg freezing team, you can contact a Treatment Coordinator on 0207 563 4306 or by completing the contact form on our website.