Bridget Jones and her creator united in travails of pregnancy

In her diary she complains about "bottom cleavage" pregnancy jeans, describes a new-found respect for toilets after weeks of morning sickness, and wonders why people feel they have the right to lay their hands on her pregnant stomach.

Now it appears that the musings of the fictional Bridget Jones are based on more than sharp observation; the 48-year-old author, Helen Fielding, is seven months pregnant.

Since August, the Jones diary has been chronicling her pregnancy by Daniel Cleaver in The Independent, but the author's real-life experiences are one month behind her heroine.

Fielding, who has a son, Dashiell, aged two, with her long-term partner Kevin Curran, executive producer and writer for The Simpsons cartoon series, is said to be "thrilled" that she is pregnant and is due to give birth in July.

She joins the growing number of successful women who are having children later in life, including Cherie Blair, who had her youngest son, Leo, in 2000, when she was 45, the singer Madonna, who had her second child, Rocco, days before her 42nd birthday, and the actress Susan Sarandon, who gave birth at 45.

The average age of mothers giving birth is now 29.4 years, while the average age for a first child is 27.5 years, two years older than in 1971, according to the Office of National Statistics.

Phillip Hodson, fellow of the British Association for Counselling and Psychotherapy, said: "There is a difference between being pregnant at 18 and at 48. What you lose in perceived energy levels you gain in experience. Children keep you younger. Having a second child is a much more comfortable experience psychologically. You know the ropes and can be more relaxed than with a first."

In the UK there are now more first-time mothers in the 30-34 age group than in the 20-24 age group. There is also a 50 per cent increase from 10 years ago in the number of women over 40 who are having babies.

The psychotherapist Elizabeth Meakins had her first child in her twenties, and her third child when she was 43. "There is a difference with energy levels," she said. "But there is no reason on earth why you cannot give a child as valuable an experience in your forties as your twenties, and in some ways you are far more laid back.

"The scare tactics of the medical profession make you feel like you are about to give birth to a monster, and that you should be drawing your pension. Motherhood is a state of mind, much more than the body's chronological age."

More than a decade ago, in October 1995, Bridget Jones's weekly column in The Independent made Fielding one of Britain's most popular diarists. She went on to sell more than 15 million books and the diaries were made into films starring Renée Zellweger as the chardonnay-drinking, calorie-obsessed protagonist.

Fielding lives in Los Angeles with Curran and has recently completed her latest work, Olivia Joules and the Overactive Imagination.

When life imitates art

* THE WEST WING

The television series about life in office for a fictional US president inspired a plot played out for real by British MPs. The "rebellion by stealth" tactics deployed by Tory MPs to defeat the Racial and Religious Hatred Bill reflected the hide-and-emerge tactics used in the drama.

* RED MERCURY

British-born Muslims perpetrate a terrorist attack on London. But this time Stockard Channing, Pete Postlethwaite and Juliet Stevenson are involved. Farrukh Dhondy's film Red Mercury played at the Cannes Film Festival last year, two months before the London terror attacks.

* 1984

Orwell's 1949 novel warns that Big Brother is watching. Now CCTV and identity cards are turning 1984's nightmare in a reality. Lorin Maazel, conductor of New York's philharmonic orchestra, who took part in the opera version of 1984, said: "That is the theme of today ... the invasion of one's private life."