The Duchess of Cambridge is expecting her third child, Kensington Palace has announced.

Monday’s announcement released in a statement says the Queen is delighted by the news.

Read the press release in full ↓ pic.twitter.com/vDTgGD2aGF

— Kensington Palace (@KensingtonRoyal) September 4, 2017

Officials say Prince William’s wife is suffering from Hyperemesis Gravidarum, a form of severe morning sickness, and will not carry out her engagements on Monday.

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.

The news was announced as the royal couple were preparing to send their eldest child, Prince George, off to school for the first time.

To see Kate Middleton’s maternity style CLICK THROUGH the gallery. Post continues…

Kate names the Clore Art Room at Barlby Primary School.

Kate meeting the kids.

The bump.

The Bump again.

Kate and Will on Christmas Day.

Kate wearing a hoody.

Kate and Will in the US.

Kate and Will in the US.

The Duke And Duchess Of Cambridge Visit The National September 11 Memorial Museum

Looking always stylish.

Posing for a photo after the game.

Kate and Will

Kate visits Northside Center For Child Development.

Kate and William arrive in New York.

Meeting some of her younger fans.

The Duchess Of Cambridge Attends East Anglia's Children's Hospices Appeal Launch.

More little fans.

Kate Middleton

The Duchess Of Cambridge Attends A SportsAid Athelete Workshop

The Duchess Of Cambridge Attends A SportsAid Athelete Workshop.

The Duchess Of Cambridge Attends A SportsAid Athelete Workshop

Kate at a remembrance day service

Kate looking stunning as usual.