The Duchess of Cambridge is expecting her third child, Kensington Palace has announced.
The announcement released in a statement says the Queen is delighted by the news.
Officials say Prince William's wife is suffering from Hyperemesis Gravidarum, a form of severe morning sickness, and will not carry out her engagements today.
Kate is being cared for at Kensington Palace, the statement said
William and Kate's two children George and Charlotte are aged four and two. Their third child would be fifth in line to the British throne.