The Victoria's Secret model – who is married to Orlando Bloom - delivered son Flynn naturally in January and while she has previously admitted her labor was "long and difficult" she has now revealed she struggled to cope giving birth without pain relief because the agony was so intense.
She said: "I actually thought I was going to die at one point and left my body. I was looking down on myself - the pain was so intense.
"I kept thinking, 'How do women do this?' But if other women have done this, I can do it too. I was determined."
The 28-year-old catwalk beauty and her actor spouse share domestic duties, refusing to have a nanny, though they occasionally get night time assistance with the baby.
She told Australia's InStyle magazine: "It's whoever has their hands free. When I'm not working we don't have a nanny. Some nights we have a lady who comes in to help out but Flynn is getting better at sleeping now, so not as often. And if I need to get on a plane for one day of work, I pump my milk and put it into the freezer for Orlando."
Miranda and Orlando divide their time between Los Angeles and London but the model wants Flynn to have some of the country experiences she had growing up so has cultivated a vegetable garden in their Hollywood home.
She added: "Flynn would love it [Australia]; I had such a wonderful childhood in the country. He is going to have a diverse upbringing."