Why Do Celeb Moms-to-Be Stay Mum?

So Nicole Kidman finally admitted it — she's pregnant.

Throw up the confetti. Pop the nonalcoholic bubbly. Woohoo.

Not to put a damper on the bundle of joy coming to Kidman and husband Keith Urban, but Hollywood insiders have been buzzing about her pregnancy for weeks. And yet, as recently as a few hours before one of Kidman's representatives confirmed the 40-year-old actress was with child, another representative staunchly denied reports that she was expecting.

Before Kidman, it was Jennifer Lopez who frustrated fans and media folk by refusing to admit she was pregnant, even after a Roberto Cavalli outfit -- and the designer himself -- revealed Jenny would soon be a mommy from the block. Fellow mom-to-be Christina Aguilera also kept silent about her status for months, though form-fitting sheathes highlighted her growing belly.

What's up with celebrities keeping their pregnancies under wraps? If you've got a bun in the oven, why not admit it, celebrate, and squash the speculation that maybe you're just growing a beer belly?

Of course, anyone who's ever been a mom-to-be knows that most women don't reveal their pregnancy during the first trimester, when the possibility of complications is most likely. And most women want to make sure their closest family and friends hear the news first — in a star's case, before her legions of fans. But while many pregnant celebrities initially stay mum for these reasons, they may also be avoiding other complications that come with being in the public eye.

"You can no longer play that sexy girl next door once you're pregnant," said Ronn Torossian, CEO of 5W Public Relations. "You can no longer be a boy band star if you have a girlfriend that you're living with. A celebrity brand is much different from a real-life person. A celebrity brand is something that is carefully cultivated, and sometimes reality gets in the way of that."

Besides wanting to maintain her industry status as a viable, bankable star, an expecting A-list actress may also have safety concerns. As soon as she admits she's pregnant, the "baby bump watch" kicks into high gear, due date speculation begins and paparazzi may start chasing her from doctor's office to yoga studio to the famous-person equivalent of Babies 'R Us.

"In New York, the paparazzi are very respectful. In California it's very difficult," said New York-based celebrity publicist Lizzie Grubman, who went through her own period of "no comment" when she was pregnant last year. "There's so much competition for that 'money shot' and there are so many photographers out there."

"It's gotten out of control," Kelly Bush, head of ID Public Relations, said about Los Angeles' relentless paparazzi. "Pregnant or not pregnant, with others or by yourself, it's become so dangerous."

'No Comment' Is Sometimes Comment Enough

Safety concerns aside, there is only so long an actress can cover an expanding midsection with artfully draped ponchos and empire-waist dresses. Grubman noted that when it comes to pregnancy, usually, "a 'no comment' is an admission." So why not simply confirm the good news if people are going to assume the baby rumors are true?

"Celebrities are hounded by the media every second. It's not an easy role, it's really not. Why do they need the added pressure, why do they need the speculation, why do they need the examination? It's just easier to say nothing sometimes," Torossian explained.

Now that Kidman has confirmed she'll be adding a third kid to her clan (she shares custody of two adopted children with ex-husband Tom Cruise), baby-bump shots, glossy magazine spreads and generously cut gowns are sure to follow. What may not, at least for the next year: many movie roles.

The New York Post reported Monday that Kidman had dropped out of the post-World War II Germany drama "The Reader" to ensure the health of her unborn child. But for the Oscar winner, less work is probably just fine.

"When you make a decision as a celebrity to have a baby, you're making a commitment for at least a year not to work," Grubman said. "If you're on TV, sometimes you work it into your character, but in the case of Nicole, I'm sure she's very excited and this is her dream come true."

Besides, she added: "There's a strike going on, she has nothing to worry about."