Kate Middleton, 35, and Prince William, 35, are expecting their third child.
They have so far remained coy on the sex of the baby, so no-one is sure if it is a boy or a girl.
But the couple have revealed their baby is due in April 2018.
Prince George and Princess Charlotte’s gender were not revealed ahead of their births, so it is assumed the same will be true for their latest baby.
However, there may be a way to tell exactly whether the Duchess of Cambridge will give birth to a boy or a girl next year.
An ancient Chinese birth predictor grid could give a clue as to the sex of the child.
The ancient Chinese birth chart, which is supposedly based on the Chinese Lunar Calendar, uses the mother’s age and month of conception to predict what gender the baby will be.
It isn’t based on science and has not been tested or endorsed by UK pregnancy officials, but it could be used as a fun way to make a guess.
Pregnant women have to match the age they will be when they give birth and the month they conceived and look down the chart to get their answer.
For Kate, this would be 36, the age she will be when she gives birth thanks to her birthday in January, and July, nine months before the due date of her baby.
According to the predictor, this means Kate and William will welcome a baby boy.
This would be the second son for the couple, following on from eldest child Prince George.
Kate has been wearing plenty of blue and pink outfits since her pregnancy was announced, leaving the public guessing as to the gender of the baby.
She recently wore a long blue jacket, hiding her growing bump, for a surprise trip out with her husband and Prince Harry to honour 150 apprentices who’ve graduated from the royals’ own mentoring programme.
She wore a log dark blue jacket with brass button detail on the front and a pair of black jeans for the appearance.
Underneath the jacket, the Duchess wore a black turtleneck long sleeve top.