Prince William’s wife Catherine is expecting the couple’s first baby, the prince’s office said Monday.

Catherine was admitted today to King Edward VII Hospital in Central London with hyperemesis gravidarum, or acute morning sickness, which requires supplementary hydration and nutrients.

“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,” the statement said.

St. James Palace said the Queen, the Duke of Edinburgh, the Prince of Wales, the Duchess of Cornwall, Prince Harry and members of both families are delighted with the news of the pregnancy.

“They will make wonderful parents,” British Prime Minister David Cameron tweeted following the announcement.