Prince William, Duke of Cambridge, leaving the King Edward VII Hospital where Catherine, Duchess of Cambridge was admitted with acute morning sickness following the announcement that she is pregnant in London, UK on Dec 3, 2012. Credit: Zak Hussein/

Doting husband -- and dad-to-be -- Prince William put his royal duties on hold for the evening to attend to his wife Monday, Dec. 3.

William, 30, was spotted leaving the Central London hospital where Kate Middleton was recently admitted.

Expecting the couple's first child together, the Duchess of Cambridge, 30, has been hospitalized with a rare condition called Hyperemesis Gravidarum, which causes intense morning sickness. (Between .03% and 1% of pregnant women will suffer from HG, whose symptoms include severe nausea, vomiting, weight loss, dehydration, lightheadedness and fainting.)

St. James's Palace confirmed Kate's pregnancy to Us Weekly Monday morning.

"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," the palace's statement read.

A palace spokesperson also cautioned that Kate's condition will require her to be carefully monitored for the next few days, at least.

Explained the statement, "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."