ACTRESS Nicole Kidman has revealed she is pregnant, reportedlywithdrawing from a film project to protect her unborn child.

Less than 18 months into her marriage to country singer KeithUrban, the 40-year-old confirmed the long-rumoured pregnancythrough her publicist Wendy Day.

“The couple are thrilled,” Ms Day said in a statement. “Foryears I’ve seen speculation and for years it’s never been right, soI didn’t think it was right this time … and then she’s justrung this morning (yesterday). I personally didn’t know, so I’mexcited … very excited.”

Ms Day told The Age that she did not know how long thestar had been pregnant and could not comment on whether gossip wastrue that Kidman had conceived through IVF.

However, Kidman’s mother, a clearly thrilled Janelle Kidman,hinted that the baby might arrive around her daughter’s 41stbirthday. “I think it’s in July,” Mrs Kidman told ChannelSeven.

Within minutes of the news hitting the internet, media crewsdescended on Kidman’s multimillion-dollar home in DarlingPoint.

Later in the day they caught up with the smiling actor and Urbanoutside the Paddington restaurant Lucio’s. But she told reportersthey were being “too personal” when they asked about the sex of thebaby, who is tipped to be born in Sydney.

Kidman has said she had an ectopic pregnancy at the beginning ofher marriage to Mission: Impossible star Tom Cruise andsuffered a miscarriage at the time the couple split.

She is mother to two children — Connor, 12, and Isabella,14 — who she adopted with her former husband.

Kidman also revealed she was withdrawing from World War II dramaThe Reader, which was to begin shooting this month. TheNew York Post reported she quit the film because she was “soconcerned about the welfare of her unborn child”.

Ms Day said Kidman “had to withdraw from the film and thereforeshe’s had to give them the reason”.

Rumours about Kidman’s pregnancy have circulated for severalweeks, with reports that she told her family during Christmasholidays in Australia that she was expecting.

Kidman, who finished filming on the Baz Luhrmann epic outbacklove story Australia last month, was also sighted in Bondibuying maternity clothes.

Over the nine months she took part in Australia, Kidmanwas joined on the set by Urban during breaks in his US musictour.

Urban was photographed holding his wife’s hand protectively overher belly last Friday as they visited the Art Gallery of NSW. OnSunday Kidman had lunch at Woolloomooloo where it was noted she didnot drink her wine.

It has been a difficult year for the Oscar-winning actress, whospent most of her time filming Australia with HughJackman.

Her husband was just out of rehab — having been addicted toalcohol and cocaine — when in April she was made a Companionof the Order of Australia by the Governor-General. Her films failedto find an audience and the marriage of her younger sister Antoniabroke up, just as she gave birth to her fourth child.

Kidman has had a glittering Hollywood career since marryingCruise in 1990.

The pair finalised their split in 2001. Roles in BatmanForever, Moulin Rouge! and Eyes Wide Shut werecapped with a best actress Academy Award for 2002’s TheHours, for her portrayal of author Virginia Woolf.

But a run of flops has dented Kidman’s seemingly unbreakablepublic visage. The Invasion, a remake of Invasion of theBody Snatchers, has grossed less than half its $US80 million($A91 million) budget in the US. Comedy Margot at theWedding failed to draw an audience and The GoldenCompass has drawn criticism for its alleged anti-Christianthemes.