It sounds like the kind of story Sex in the City's columnist Carrie Bradshaw would agonise over for hours in front of her Apple laptop as she made her way through a pack of Marlboro Lights.

A deeply in love couple have a son and for the next six years try for another child but nothing seems to work. Eventually they decide that their last resort will be to use a surrogate mother to provide them with the child of their dreams. But as Carrie, who always ended her columns with a question mark, might say: Isn't surrogacy the ultimate taboo?

Not if you are Sarah Jessica Parker, who played Carrie Bradshaw throughout the HBO hit series, and is having twins with a surrogate mother this summer. Yesterday Parker, who is married to actor Matthew Broderick, confirmed the news through their publicist.

“Sarah Jessica Parker and Matthew Broderick are happily anticipating the birth of their twin daughters later this summer with the generous help of a surrogate. The entire family is overjoyed,” the publicist said.

A friend of the pair told Entertainment Weekly that they had been trying to add to their family ever since the birth of their son James Wilkie six years ago. “They had a lot of unsuccessful tries,” the friend said.

“They came to the conclusion that this was going to be the best alternative for expanding their family.”

Barring any complications, the Parker-Brodericks will become just one of hundreds of families in the States who rely on surrogacy to provide them with a child. It is a process which has become increasingly popular among celebrities.

To its critics, surrogacy is considered morally questionable because it challenges our most basic ideas about motherhood and the supposedly unbreakable bond between a mother and her child. But supporters say it offers a lifeline to couples who are desperate to have a child and have exhausted all other means.

According to the Society for Assisted Reproductive Technology — the only organisation in the States that tries to keep track of surrogate births — 256 babies were born through surrogate mothers in 2007, an increase of 30% over four years.

However, 15% of US clinics are not members of SART and keep their data secret so the true extent is thought to be much higher, possibly as many as 1,000 births per year. America remains the surrogacy capital of the world.