Behind those statistics lies a complex and emotional picture. Many of the conceptions resulted in children born to couples who feared it was too late, sometimes after years of fertility treatment. For others, such as Mrs de Lange, the conception comes as more of an unexpected addition to the family.
This change reflects a subtle but significant shift in society and its attitudes. As we live longer, “mid-life” is stretching further away. Whereas in the past, women in their forties were regarded as solidly middle-aged, today’s fortysomethings – the Sex and the City generation – see themselves as still youthful, and certainly not old enough to rule out children.
Dr Linda Blair, a clinical psychologist, says: “Women see themselves as sexual, and are sexually active, for far longer than they used to be. Of course, that doesn’t always tie in with pregnancy, but it can.” As older mothers fuel the baby boom, the abortion rate among the over-forties has dropped markedly, from 42 to 28 per cent in two decades.
Last October, Carla Bruni became the latest poster girl for the older mother, when, aged 43, she gave birth to her daughter Giulia. The wife of French President Nicolas Sarkozy follows a host of high-profile mothers, including choreographer Arlene Phillips, who had her youngest child at 47, actress Jane Seymour, with twins at 44, and Bridget Jones author Helen Fielding, who had a child at the age of 48.
According to the Office of National Statistics – whose latest figures show there were more than 900,000 pregnancies in England and Wales in 2010, higher than the peak of the post-war baby boom in 1964 – the record level has been fuelled not only by the number of older women having children but also by the impact of a recession on people’s values and attitudes. In tough economic times, its report suggests, family might be valued more highly.
Cari Rosen, a former television executive from north London who now works part-time for the website Gransnet, was “43 and a quarter” when she gave birth to her daughter, now three. She says the economics of having a child later in life have made it easier to put the family first.
“A lot of my friends felt under pressure to go back to work full-time when their kids were young, but being older I didn’t – partly because at my age I have more financial security, and partly because I feel less pressure to prove myself career-wise.”
Her husband, Rob, a charity director, has time to be a “very hands-on dad”.
Ms Rosen, now 46, dismisses those who criticise later-life parenthood. “I didn’t meet someone I wanted a child with until I was 39. Before that, the question was: ‘Do you have a child with someone you don’t want to spend the rest of your life with – or do you cross your fingers that you will meet the right person?’ People say it’s selfish, but it seems to me more selfish to bring a child into a relationship that is not right. I think some women do make that compromise.”
She admits that there are times when dealing with a child makes her feel her age: “The other day I was moaning about grey hairs, and it did make me think that when my daughter starts school, I don’t want to be looking my age at the school gates.” Yet she says she cannot be sure she would have any more stamina if she were any younger.
In Blackheath, south-east London, Linda de Lange, now 56, and Matthew, 59, are enjoying bringing up Benjamin, who, at eight, is 20 years younger than their oldest son. She believes that her and her husband’s experience and age have given them a more relaxed approach to parenthood.
When stamina is in short supply, patience can fill the gaps. “I have learnt there are some fights not worth having with your children. I did a huge amount of shouting with the others,” she laughs.
Older couples have been able to bring up a child in later life by taking advantage of the shifts in the way we work – keeping flexible hours or logging in at home. Two decades ago, Mr de Lange was keen to be a hands-on father, but was working long hours in a bid to become a partner at the accountancy firm PriceWaterhouseCoopers. Now he runs his own business from home, and is able to be more involved in day-to-day parenting.
Given that the children of Mrs de Lange’s friends were largely grown up, she decided to make friends with pregnant women who were decades younger. Attending classes run by the National Childbirth Trust enthused her so much, she is now training to become an antenatal teacher.
“Doing it this time around, I can recognise the changes in how we bring up children,” she says. “I don’t think it is all about age. Mothers these days seem more scared of the world than they used to be – a bit risk-averse, a bit more worried about what will happen if their child doesn’t wear a coat outdoors.
“If you have been through it once, it is easier to see that children are their own people, that they take their own decisions – and it’s not all your fault.”