Bookies predict the Duke and Duchess of Cambridge will make sudden announcement of royal baby number four before end of year

Is this PROOF Kate and William will have 4th baby?

The Cambridges set to expand their brood. - by Grace Back

As the Duke and Duchess of Sussex prepare to welcome their first child together in 2019, the bookies are offering odds on the Duke and Duchess of Cambridge making a sudden announcement too.

Betting site Ladbrokes have odds of just 7/2 for Prince William and Kate Middleton revealing they are expecting their fourth child by the end of the year.

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Alex Apati of Ladbrokes said: "Baby mania is in full swing in the Royal Family right now so it's no surprise to see odds on a fourth Will and Kate baby so short."

The Cambridge parents already share three children - Prince George, 5, Princess Charlotte, 3, and Prince Louis, 6-months.

Earlier in the year, Kate’s former school friend Jessica Hay exclusively told New Idea how she makes motherhood look easy.

"They’re a family of five now, so I would expect them to have one more baby to make a nice round number of six before long," Jess said.

"In fact, William’s telling everyone that they would love to have one more baby in the next 18 months!"

This article originally appeared on New Idea.

Grace Back

Grace is the Digital Content Editor at New Idea. Grace is a lifestyle junkie who has previously interned at Dolly, Stellar and marie claire, as well having written in the fashion and beauty sections at Finder.com.au. When not working, you can find Grace heading for the slopes, playing with her pup or stuck in a seemingly endless Instagram scroll.