Media release

From: Taylor and Francis Group

Donor eggs drive most IVF successes for women over 43, major new UK study finds

• “Little improvement” in success rates for older women using their own eggs for assisted reproductive technology – 27 years of data highlight 
• These results from more than 1.2 million treatment cycles are important for women worldwide, with delayed childbearing becoming more common

Most successful fertility treatments for women aged 43 years and older rely on donor eggs, according to a study involving more than half a million patients in the UK.

The peer-reviewed research, published today in Population Studies, provides the most comprehensive analysis to-date, worldwide, of how age and egg source influence the contribution of fertility treatments to birth rates. It highlights the crucial role of donor eggs in the success of assisted reproductive technologies (ART), such as in vitro fertilisation (IVF), for older women.

Led by academics from the London School of Economics and Political Science (LSE) and University of Vienna, the findings reveal that although fertility treatments have become more widely used and increasingly effective over recent decades, success rates for ART using a woman’s own eggs still decline sharply with age.

As a result, from the age of 43 onwards, most ART-conceived births are achieved through donor egg treatments.

“I personally didn’t know how low ART success rates are for older women using their own eggs and was really surprised to see that success rates remain completely stable with donor eggs.

When you see the numbers for the first time, it’s striking how little the age of the woman matters and how it’s really all about the age of the eggs. Our study shows that while ART has become much more effective in general, it currently cannot overcome certain biological limits,” says lead author Luzia Bruckamp, a PhD student in Economics, at LSE, whose research focuses on fertility choices and the strong trend of falling birth rates everywhere in the world.

“For women over 43, treatments using their own eggs are rarely successful. Donor eggs often remain the only reliable option for achieving a successful pregnancy at older ages.”

Luzia’s research passion is to understand why fertility is falling even further below replacement and what help can be offered to enable people to have the number of children they want. 
She teamed up with Dr Ester Lazzari, from the Wittgenstein Centre for Demography and Global Human Capital, at Vienna, who is interested in studying the barriers that prevent people from realizing their ideal family size.

The aim of their study was to better understand the difference between ART treatments when using either donor or non-donor eggs. Most research to-date has assessed the impact of using both, making it difficult to isolate the age-specific effect of the different treatments on fertility rates.

Across Europe, over 80,000 egg donation cycles are performed annually (accounting for 7.6 per cent of total ART cycles), with this number steadily increasing each year.

According to a recent report by the UK’s Human Fertilisation and Embryo Authority (HFEA - the independent regulator of fertility treatment in the UK), births using a donated egg or embryo have increased more than fourfold, from 320 in 1995 to around 1,300 in 2019, and such procedures now account for half of all ART procedures among women aged 45–50.

As maternal age at first birth continues to increase, the demand for donor eggs is likely to continue growing – making it important to understand the contribution of these treatments to overall fertility trends.

To do this, the team analysed data from HFEA which included all ART procedures carried out in licensed clinics between 1991 and 2018. The data covered more than 1.2 million treatment cycles and over half a million patients undergoing their first treatment.

Results highlight a sharp increase in the use of ART over time. Precisely:

• The number of people beginning fertility treatments each year increased from around 6,000 in 1991 to nearly 25,000 by 2018.

• Over the same period, overall success rates nearly doubled – rising from 14.7% in 1991 to 28.3% in 2018.

• Both maternal age and egg source remain key factors in determining success. Success rates for ART using a woman’s own eggs show a clear age-related decline, with outcomes falling sharply at older ages.
• Among those aged 43 and above, success rates remain below 5% when using their own eggs. In contrast, more than one-third of treatments using donor eggs are now successful across all age groups.

The researchers also examined how these trends have influenced overall fertility rates in the UK. In 1992, ART accounted for just 0.3 per cent of all births; by 2018, that share had risen to 3 per cent. The impact of ART is most striking among women aged 43 and older, where the increase is driven largely by donor egg treatments. In 2018, these accounted for more than half of ART births at age 43 to 44, and more than 90% among women aged 45 to 50.

“Many people may not be fully aware of the implications of postponing parenthood. While assisted reproduction can help many to achieve their desired family size, it cannot completely counteract the effects of maternal age,” adds co-author Dr Lazzari.

“Our findings indicate that fertility recuperation at advanced ages is highly unlikely to succeed with ART using a patient’s own eggs. Egg donation and egg freezing can improve the chances of conception, but they also have important limitations making them insufficient to fully offset the fertility loss associated with delayed childbearing.

“These findings carry an important message not just for the UK, but for societies worldwide, where delayed childbearing is becoming more common.”

The authors call for clearer public health communication about the realistic success rates of ART at different ages – and the likelihood that older women may need to use donor eggs or consider freezing their own eggs earlier in life – to support informed reproductive decision-making.  

They also emphasise the importance of broader policies that make it easier for those who wish to have children earlier in life to do so – through greater economic security, workplace flexibility and family-friendly support. Such measures could help reduce the risk of age-related infertility and the growing reliance on complex reproductive technologies later in life.

Limitations of the paper include the data set not accounting for patients who travel abroad for treatment, meaning that those cases remain unobserved.