Kate Middleton and Prince William reveal third child is due in April

The royal baby will arrive in April.

Kate Middleton
Britain's Prince William (2nd L), Catherine, Duchess of Cambridge, Prince George (L) and Princess Charlotte (R) Reuters

Kate Middleton and Prince William have revealed when their third child is due. The royal baby will arrive in April.

Kensington Palace announced the news on Twitter. The statement read: "The Duke and Duchess of Cambridge are delighted to confirm they are expecting a baby in April 2018."

The royal couple have two children, Prince George and Princess Charlotte. And in September it was revealed that Kate is pregnant. She had to cancel many official engagements as she was suffering from severe morning sickness, like with her previous two pregnancies.

On 10 October, Kate made first public appearance since announcing her third pregnancy. Buckingham Palace hosted the event in honor of World Mental Health Day.

Adding on, the royal couple, along with Prince Harry attended the Charities Forum Event on board the Belmond Britigh Pullman train at Paddington Station on 16 October. The Duchess also danced with Paddington bear on the platform.

A royal source told ABC News: "Her condition is improved, but the duchess does continue to be affected by hyperemesis gravidarum. She is making decisions day to day but is keen to do as much as she can."