LONDON -- Get the nursery ready: Prince William and his wife Kate are expecting their first child.
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.
The palace said since the pregnancy is in its very early stages, the 30-year-old duchess is expected to stay in the hospital for several days and will require a period of rest afterward.
It would not say how far along she is, only that she has not yet reached the 12-week mark.
News of the pregnancy drew congratulations from across the world, with the hashtag royalbaby trending globally on Twitter.
Not only are the attractive young couple popular with William s easy common touch reminding many of his mother, the late Princess 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 eventually become a monarch.
In recent days, Middleton has kept up her royal appearances recently playing field hockey with schoolchildren at her former school.
The confirmation of her 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 the late Princess Diana got pregnant just four months after her wedding in 1981. Diana reportedly suffered from morning sickness for months and complained of constant media attention.
The whole world is watching my stomach, Diana once said.
American tabloid speculation of the pregnancy has been rampant for months. One newspaper even cited anonymous sources talking about Kate s hormone levels. Others have focused on the first signs of the royal bump.
The palace said the royal family was delighted by the news, while British Prime Minister David Cameron wrote on Twitter that the royals will make wonderful parents.
Whether boy or girl, the child will be next in line behind William in the line of succession to the throne, Cabinet Office officials have said.
Leaders of Britain and the 15 former colonies that have the monarch as their head of state agreed in 2011 to new rules which give females equal status with males in the order of succession.
Although none of the nations had legislated to make the change as of September 2012, the British Cabinet Office confirmed that this is now the de-facto rule.
On the couple s recent tour of Malaysia, Singapore, the Solomon Islands and Tuvalu in September, William reportedly said he hoped he and Kate would have two children.
Why was pregnant duchess hospitalized?
While morning sickness in pregnant women is common, the problem the Duchess of Cambridge has been hospitalized with is not.
In a statement Monday, palace officials said she 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. Palace officials said the duchess was expected to remain hospitalized for several days and would require a period of rest afterwards.
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 and tends to be more common in young women, women who are pregnant for the first time, those expecting multiple babies and in non-smokers. Gaither said that fewer than one percent of women with the condition need to be hospitalized.
Doctors aren t sure what causes it but suspect it could be linked to hormonal changes or nutritional problems.
Women admitted to the hospital with hyperemesis gravidarum are usually treated with nutritional supplements and given fluids intravenously to treat dehydration. Dr. Dagni Rajasingam, a spokeswoman for the Royal College of Obstetricians and Gynaecologists, said most women hospitalized with the condition are discharged within several days.
It depends on how well the woman is keeping fluids down, she said.
If the problem is recognized and treated early, doctors say there are no long-term effects for either the mother or the child. Left untreated, the mother could be at risk of developing neurological problems including seizures or risk delivering the baby early.
Gaither said the condition usually subsides by the second trimester.
The rest of the pregnancy could be entirely uneventful, she said, adding that pregnant women treated for the condition are usually advised to avoid fatty foods that could aggravate the problem.
Gaither said the duchess would probably be able to meet her usual royal obligations by her second trimester.
She should be able to meet all her public obligations soon, she said, advising her to take her vitamins and ensure there are no other underlying health problems. She should just be looking forward to having a healthy little plump person.