St. James Palace confirmed Monday that Kate was admitted to a central London hospital with acute morning sickness, and is expected to remain there for several days. Otherwise, the families "are delighted with the news."
“As the pregnancy is in its very early stages, Her Royal Highness is expected to stay in hospital for several days and will require a period of rest thereafter,” a palace spokesman said.
Their Royal Highnesses The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting a baby. The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall and Prince Harry and members of both families are delighted with the news.
President Obama offered his congratulations to the couple Monday afternoon. At the daily briefing in Washington, White House press secretary Jay Carney said Obama and first lady Michelle Obama passed along congratulations to William and Kate "on the welcome news out of London."
Pregnancy rumors have been intensifying for weeks, particularly since the Duke and Duchess took an extended tour of Southeast Asia last month, eschewing alcohol at several toasts.
Last week, William set the rumor mill abuzz when he accepted a gift from a well-wisher on Wednesday. Samantha Hill handed William a baby's onesie, decorated with a helicopter and the slogan "Daddy's little co-pilot," and the duke accepted it happily.
"When I gave it to him he said 'I'll keep that," and handed it to his aide," Hill told reporters.
And photos of Kate covering her stomach as she walked up some stairs, coupled with an unusually blouson dress, raised further questions.
As the news broke Monday, "#royalbaby," "Kate and Will," "Buckingham Palace" and "Duchess of Cambridge" all began trending on Twitter worldwide almost immediately. Tweets came in from celebrities and other British personalities offering their congratulations.
PM: "I’m delighted by the news that the Duke & Duchess of Cambridge are expecting a baby. They will make wonderful parents." #royalbaby— UK Prime Minister (@Number10gov) December 3, 2012
I'm sooooooo excited that we're having a royal baby !!!! Congratulations to Kate and Wills !!!!!!— Cheryl Cole (@CherylCole) December 3, 2012
BBC broke #royalbaby story, Guardian now live-blogging on it, Tabloids waiting to be condemned by both for trivial journalistic priorities.— Piers Morgan (@piersmorgan) December 3, 2012
Congrats to Kate, William & our royal patron HM Queen Elizabeth II on the news of the #royalbaby from everyone at ZSL London Zoo!— ZSL London Zoo (@zsllondonzoo) December 3, 2012
Congratulations to the Duke & Duchess of Cambridge for the #royalbaby. We shall name it, "The Half-Blood Prince". ;)— Students of Hogwarts (@OhHogwarts) December 3, 2012
A royal baby!!!!!!!!!!!!! perez.ly/RwAaCD— Perez Hilton (@PerezHilton) December 3, 2012
Many instead congratulated themselves on guessing right, pointing out all the signs that seem obvious in hindsight.
Hardly surprising Kate's feeling so sick - according to the National Enquirer, she's been pregnant since 2003. #royalbaby— Piers Morgan (@piersmorgan) December 3, 2012
Notable deaths of 2014 [PHOTOS]