St James's Palace has announced that the Duke and Duchess of Cambridge are expecting their first child.
The Duchess was admitted this afternoon to King Edward VII Hospital in central London with acute morning sickness.
As the pregnancy is in its very early stages, she is expected to remain there for the next few days.
Prime Minister David Cameron took to Twitter to congratulate the royal couple.
"I'm delighted by the news that the Duke and Duchess of Cambridge are expecting a baby. They will make wonderful parents," he tweeted.
The news comes just days after the couple's inaugural trip to their dukedom - Cambridge - where the Duke, an RAF search-and-rescue pilot, received a home-made romper suit from a new mum.
The baby grow was emblazoned with a picture of a helicopter and the words "Daddy's little co-pilot".
The Duke, all smiles, received the gift saying: "Fantastic, I'll keep this."