Miranda Kerr suffered a heartbreaking miscarriage

During an appearance on the 'Not Alone' podcast, Miranda spoke about being mum to four boys and added: "I was always in my heart of hearts happy regardless of the gender and I also actually had a miscarriage and it was a boy as well. So that was technically my fifth boy. My son now is my fifth boy technically. He's a rainbow baby and he's so sweet but each of them was so different."

Miranda went on to explain she was "very naive" during her first pregnancy and with every subsequent baby she became more "knowledgeable" but also "more concerned" about something going wrong.

She added: "With each pregnancy I became more knowledgeable and a little more concerned or worried about what might go wrong whereas my first pregnancy I was like: 'Wow this is so ... ' I was just very naive. And now you know more and you kind of worry more in that regard."

Miranda also revealed she experienced difficulties with each of her pregnancies after welcoming Flynn and had to be placed on bed rest for the final few months every time - and it was a struggle to care for her other kids.

She added: "I had to be on bed rest for the last couple of months with all of them except for Flynn and that's really hard navigating bed rest when you have children. "

It comes after the Victoria's Secret star revealed her youngest son Pierre was named after her late grandfather, Peter.

She told PEOPLE: "His name is Pierre after my late grandfather, Peter. So French for Peter."

Miranda added her elder boys all love their new baby brother. She told the publication: "He's just a little ray of sunshine and his brothers just adore him.

"And when you're having a new baby coming into the home, you often wonder, you're like, 'Oh, how are the boys going to react?' But they adore him."