The news broke early this morning in an official announcement:
"Their Royal Highnesses The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting their second child. The Queen and members of both families are delighted with the news."
Unfortunately, the happy news comes with details that extreme morning sickness will sideline Kate from an upcoming engagement, as the statement explained: "As with her first pregnancy, The Duchess is suffering from Hyperemesis Gravidarum. Her Royal Highness will no longer accompany The Duke of Cambridge on their planned engagement in Oxford today. The Duchess is being treated by doctors at Kensington Palace."
William and Kate welcomed their first son, George, in July 2013.