And during the chat, Kate, 38, admitted standing outside the Lindo Wing following the birth of her eldest child, Prince George, was "terrifying".
"What was it like knowing that so many people were outside, after you've given birth and you're in your little cocoon with your new family?" Giovanna asked.
"Yeah, slightly terrifying, slightly terrifying, I'm not going to lie," explained Kate.
"Everyone had been so supportive and both William and I were really conscious that this was something that everyone was excited about and you know we're hugely grateful for the support that the public had shown us, and actually for us to be able to share that joy and appreciation with the public, I felt was really important.
"But equally it was coupled with a newborn baby, and inexperienced parents, and the uncertainty of what that held, so there were all sorts of mixed emotions."
Mum-of-three Kate explained she was very keen to get home and return to normality following the birth of George, especially after suffering from hyperemesis gravidarum throughout her pregnancy.
"Being in hospital, I had all the memories of being in hospital because of being sick so it wasn't a place I wanted to hang around in," she explained.
"So, I was really desperate to get home and get back to normality. But I think you think, particularly with your firstborn baby, you think everything is going to go back to how it was.
"I totally underestimated the impact and the change it had on our lives from that moment really and I think, unless you've got children, you don't realise. No amount of planning and preparation can get you ready for that moment."
Duchess, who is mum to George, six, Charlotte, four and Louis, one, appeared on the podcast following the launch of the '5 Big Questions on the Under Fives' survey and a visit to a London Early Years Foundation nursery in Stockwell.
During the chat, Kate also opened up on mum guilt, explaining it's something she regularly experiences.
"Even this morning, coming to the nursery visit here, George and Charlotte were like 'Mummy how could you possibly not be dropping us off at school this morning?'" she said.
"It's a constant challenge [...] even mums who aren't necessarily working and aren't pulled in the directions of having to juggle work life and family life [...] always sort of questioning your own decisions and your own judgements and things like that, and I think that starts from the moment you have a baby."
You can listen to the special episode of Giovanna's podcast here.
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