Rise of celebrities having kids in their mid-40s like Sienna Miller is ‘causing a fertility crisis’, warn doctors who say chances fall rapidly after 28

The swathe of celebrities having babies in their mid-40s is giving women false hope over their chances of conceiving later in life, experts have warned. 

Actress Sienna Miller, 41, is one of the latest celebs to reveal she is becoming an older mum, now expecting her second child.

Super model Naomi Campbell, 53, welcomed her second child via surrogate in June and said ‘it’s never too late’. 

Others movie star Michelle Williams, 41, who had a baby late last year, currently pregnant Orange is the New Black star Uzo Aduba and Oscar winner Hilary Swank, who had twins at 48 this year.

But fertility experts warn such success stories are luring women in their 30s and 40s into a false sense of security and contributing to women choosing to delay having children.

While conception rates vary for individual women  it is universally accepted by experts that fertility levels peak when younger then generally begin to fall off by the late 20s and then rapidly decline from the mid-30s onwards 

One year after her first Tony Award nomination for Clyde’s, Uzo Aduba revealed she’s expecting her first child with husband Robert Sweeting

Hilary Swank showing off her growing baby bump on Instagram in February 

Michelle Williams, 41 had her baby in October 2022, here he pictured during the 75th annual Cannes film festival in May that year

They noted that most women in their early 40s only have a 5 per cent chance of becoming pregnant per month of trying.

And for those aged over 45, the odds of successfully conceiving fall to just 1 per cent.

Doctors said celebs often have the money to fuel multiple expensive fertility treatments out the reach of many regular couples.

Age is one of the biggest factors determining how fertile a woman is, with experts saying that women in their late twenties have the best chance of success before the odds rapidly decline from their mid-30s.

Even in vitro fertilisation (IVF) – when eggs are collected and fertilised in a lab before being implanted into the womb a process that has helped thousands of women unable to convince naturally become mothers- may not prove successful. 

Hopeful mums in their early 40s only enjoy an 11 per cent success rate via IVF, declining to just 4 per cent in women aged 44, according to the NHS.

For this reason, the health service doesn’t usually recommend IVF for women over 42 as the success rate is considered too low.

Dr Tim Bracewell-Milnes, an expert in reproductive medicine from Imperial College London, told MailOnline that many hopeful mums in their forties will not have children naturally.

‘The reality for women in their forties trying to conceive is that the majority of them will not be able to, especially in their mid-forties,’ he said.

He warned women looking to older celebs enjoying a successful pregnancy that these stars likely employed specialist techniques to boost their chances.

‘When reading these articles about celebrities in their forties having children, women should be aware that the vast majority of them will have conceived with IVF by either using their own eggs they froze when they were younger, or a donor egg from a younger woman to conceive,’ he said.

‘Of course it is the celebrity’s right to not disclose the nature of their conception.’

But he noted such examples could be luring older women into a false sense of security that they plenty of time to have children naturally.

‘The media attention these celebrity pregnancies are giving to the general public is currently giving a false message that could, at least partially, be contributing to them delaying having children.

‘Many women are currently being indirectly falsely reassured about how easily they could conceive when they’re older.’

He urged women wanting to have children later in life to seek out professional advice on their fertility, ideally before the age of 36.

Pregnancies among women over 40 have soared to the highest level since records began before the turn of the century (brown line). Yet conceptions among teenagers have plunged over the same period, despite rebounding slightly last year (grey line)

Professor Adam Balen, an expert in reproductive medicine and former chairman of the British Fertility Society, also warned that many older celebrity mums use expensive egg donor treatments to boost their chances.

‘Many conceptions in celebrities are with donor eggs as IVF doesn’t work over 45-years,’ he said.

He said such donor eggs, which are harvested from younger women and are more viable, can boost the odds of successful conception in an older woman by up to 40 per cent.

However, such treatments are expensive, costing at least £5,000 per round and often even more.

Hopeful older mums don’t just have to contend with reduced odds of conception.

They also run a higher risk of suffering from complications in their pregnancy.

The figures also reveal the conception rate for women aged 40 and over has continued to rise and is now at a record high of 17.3 conceptions per 1,000 women

Experts have previously warned that older celeb pregnancies risk ‘glamourising’ being an older mum without highlighting these risks. 

Such complications include high blood pressure and pre-eclampsia, congenital abnormalities, such as Down’s syndrome, and even miscarriage and stillbirth. 

While individual conception odds will vary per individual woman about seven in 10 of those in their early 30s will become pregnant within a year of trying. 

This falls to around six in 10 among those in their mid-30s and falls to about 4 in 10 when they reach 40 then decreasing to just one in 10 among those aged 45. 

Other experts, who published their research in the journal of Human Reproduction in 2021, have put these figures even lower.

Some claim 19 to 26-year-olds only have up to a 50 per cent chance of conceiving two days before ovulation – a woman’s most fertile time.

But this drops to 40 per cent for those aged 27 to 34.

After 35, the women studied had only a 30 per cent chance of falling pregnant in any given month. 

Official data shows rising numbers of women are looking to delay having children.

Figures from the Office of National Statistics, published in March, show pregnancies among women over 40 soared in 2021 to the highest level since records began.

Of the 824,983 conceptions were recorded across England and Wales more than 33,000 were among those of an ‘older’ maternal age — the most ever logged.

Experts believe the increase in older women conceiving is because they are opting to have kids later in life while they pursue careers and relying on advances in IVF and other fertility treatments as a fallback. 

The NHS says while most couples trying for a baby should be successful within a year those who aren’t should contact their GP for advice.