Richmond-upon-Thames is the older mum capital of England and Wales, MailOnline can reveal today.
In the affluent London borough, the majority of babies are now born to women over-35.
Rates of ‘geriatric motherhood’ have trebled in dozens of authorities since the early 1990s.
It reflects how women are increasingly choosing to put off having children until later in life in order to pursue a career.
At the same time, figures show teenage pregnancies have slumped to all-time lows.
For Richmond-upon-Thames, the Office for National Statistics (ONS) recorded 1,674 births in 2023.
Of those, 838 (50.1 per cent) were to women over the age of 35.
This means they fall into the category now known as advanced maternal age (AMA), with ‘geriatric pregnancy’ considered an outdated term.
The equally affluent borough of Kensington and Chelsea ranked just behind (47.4 per cent), followed by Elmbridge in Surrey (43.7 per cent).
Camden (42.8 per cent) and Westminster (42.8 per cent) rounded out the top five.
Bolsover, in Derbyshire, had the fewest number of new mums aged 35 and over (13.8 per cent), while Blaenau Gwent has the fewest in Wales (14.4 per cent).
The Vale of Glamorgan (27.2 per cent) had the highest in Wales.
When the ONS began recording the topic in 1993, the City of London was the only area where 30 per cent of live births were to women over 35.
By 2023, 68 authorities – just over a fifth of all the 300-plus councils in England and Wales – had hit the threshold.
The rising average age of mothers has been linked to women choosing to pursue careers over starting a family in their twenties, as well as financial pressures like the cost of childcare.
Kerry Gadsdon, from the ONS, said: ‘The reasons behind when and if women have children are very personal.
‘This may be driven by a range of factors including financial pressures and the timing of other life events such as partnership formation and moving into your own home generally happening later.’
Dr Ippokratis Sarris, director of the King’s College London fertility clinic, said: ‘Fertility naturally declines with age, particularly after 35.
‘The chances of pregnancy complications, such as miscarriage, high blood pressure, and chromosomal abnormalities like Down’s syndrome, increase.
‘Fertility treatments, including IVF, also become less effective with age, with success rates falling significantly after 40.
‘However, advances in fertility treatments and obstetric care mean that more women than ever are able to have healthy pregnancies later in life.
‘It’s important that as healthcare professionals we support women’s choices by providing accurate information about how age impacts fertility and pregnancy, to help individuals make informed family planning decisions.’
The findings come after MailOnline last month revealed how fertility rates have plunged in every local authority in England and Wales over the past decade.
Amidst the so-called ‘baby bust’, some boroughs saw a 60 per cent decline in women having children since 2013.
Experts fear the freefalling rates will trigger an ‘underpopulation’ crisis with women in England and Wales, on average, now only having 1.44 children.
