Kate Middleton was warned not to have another child before announcing pregnancy with Prince Louis

Prince William and Kate Middleton are parents to three beautiful children, Prince George, Princess Charlotte and Prince Louis.

The Prince and Princess of Wales often open up about family life, whether it's sharing Louis' favourite celebrity or Charlotte's fancy go-to snack.

They have always worked hard to ensure that, despite being in the public eye, their three little ones have a sense of normality when it comes to their upbringing; they use a 'chat sofa' to discipline the young royal children and Kate even stays up late baking their birthday cakes.

However, just before announcing that they were expecting their third child, William and Kate were warned not to have any more children.

During a tour of Poland and Germany in the summer of 2017, Kate was reportedly given a baby toy whilst in Warsaw. As George and Charlotte were four and two at the time, she is believed to have said to William: 'We'll just have to have more babies!'

Shortly afterwards, children's organisation 'Having Kids' - which promotes a 'sustainable and child-centred family planning model' - urged the couple to reconsider expanding their family.

In an open letter, Executive Director President Anne Green Carter Dillard wrote that 'the example the British Royal Family sets is extremely influential,' continuing: 'Your discussion of having a larger family raises compelling issues of sustainability and equity.

'Large families are not sustainable.'

She added that while George and Charlotte are 'certain to have wonderful lives... the same can't be said of every future child.'

Two months later, in September 2017, the couple shared the news that they were expecting their third child, and Louis was born in April 2018.

Royal fans have been hoping that a fourth Cambridge baby could be on the way, but during a trip to Northern Ireland last year someone called out to Kate: 'Number four?'

She replied: 'I think William would be a little worried!'

Well, that's that!