Tom Hevezi, File, Associated Press
LONDON — The most widely anticipated pregnancy since Princess Diana's in 1981 is official: Prince William's wife, Kate, is pregnant.
St. James's Palace announced the pregnancy Monday, saying that the Duchess of Cambridge — formerly known as Kate Middleton — has a severe form of morning sickness and is currently in a London hospital. William is at his wife's side.
News of the pregnancy drew congratulations from across the world, with the hashtag "royalbaby" trending globally on Twitter.
The couple's first child will be third in line to take the throne — leapfrogging the gregarious Prince Harry and possibly setting up the first scenario in which a U.K. female heir could benefit from new gender rules about succession.
The palace would not say how far along the 30-year-old duchess is, only that she has not yet reached the 12-week mark. Palace officials said the duchess was hospitalized with hyperemesis gravidarum, a potentially dangerous type of morning sickness where vomiting is so severe no food or liquid can be kept down. They said she was expected to remain hospitalized for several days and would require a period of rest afterward.
"It's not unusual for pregnant women to get morning sickness, but when it gets to the point where you're dehydrated, losing weight or vomiting so much you begin to build up (toxic) products in your blood, that's a concern," said Dr. Kecia Gaither, director of maternal fetal medicine at Brookdale University and Medical Center in New York.
The condition is thought to affect about one in 50 pregnant women but Gaither said less than one percent of women with the condition need to be hospitalized.
The news came just days after the duchess, on a royal appearance, was playing field hockey with schoolchildren at her former school.
Not only are the attractive young couple popular — with William's easy common touch reminding many of his mother, the late Diana — but their child is expected to play an important role in British national life for decades to come.
William is second in line to the throne after his father, Prince Charles, so the couple's first child would normally become a monarch — eventually.
The confirmation of Kate's pregnancy caps a jam-packed year of highs and lows for the young royals, who were married in a lavish ceremony at Westminster Abbey last year.
They have traveled the world extensively as part of Queen Elizabeth II's Diamond Jubilee celebrations and weathered the embarrassment of a nude photos scandal, after a tabloid published topless images of the duchess.
Joe Little, managing editor of Majesty magazine, said the news bookended a year that saw the royal family riding high in popular esteem after celebrations of Queen Elizabeth II's 60 years on the throne.
"We're riding on a royal high at the moment at the end of the Diamond Jubilee year," he said. "People enjoyed the royal romance last year and now there's this. It's just a good news story amid all the doom and gloom."
Speculation about when the couple would start a family has been rife since their wedding.
William's mother Diana got pregnant just four months after her wedding in 1981. Diana also reportedly suffered from morning sickness for months and complained of constant media attention.
"The whole world is watching my stomach," Diana once said.
She gave birth to William in 1982 after 16 hours of labor. At his birth, William was given a baby tag marked 'Baby Wales' and a 41-gun salute was fired in Hyde Park and the Tower of London.
- Photo gallery: Night skies over national parks
- Rep. Jason Chaffetz says he wouldn't run...
- Is 'Speaker Chaffetz' more likely with...
- Ann Romney on likability, Hillary Clinton, MS...
- Does your child struggle to focus? Here's why...
- Police arrest man who posed as Mormon...
- McCarthy abruptly withdraws candidacy for...
- VW executive apologizes but says scandal not...
- Is 'Speaker Chaffetz' more likely with... 68
- Workers removing Ten Commandments from... 56
- Chaffetz's run for speaker makes... 47
- Mother-son bond over guns links Oregon,... 22
- 40 percent tax on employer insurance... 22
- Clinton pitches new gun controls... 16
- Obama touts immigration reform in... 16
- Judge dismisses negligence lawsuit... 15