Ms Thwaites and Ms d'Ews Thomson are among a growing number of mums choosing to have what is known as physiological childbirths.

Ms Thwaites, 33, gave birth to son Luca Mortelliti three weeks ago and went for her first post-pregnancy walk the very next day.

Asked about her choice, Ms Thwaites said: "It's a natural thing to do – nature has supposedly designed us that way and people have been doing it like that since the beginning of time.

"It's logical really. It's more logical than opting for intervention," she said.

Ms d'Ews Thomson had home births for her daughter Isobel (2½) and son Theodore (seven weeks).

"I didn't want to go hospital because I know it's quite easy to fall down the slippery slope of intervention. I'm a young fit woman and I was totally convinced I could do it and I completely trusted my body to be able to handle what it's made to do," the 29-year-old said.

The Kambah mum said her recovery after giving birth to both her children had also been really easy.

Physiological births – which have also been called normal births – were discussed at a workshop and seminar at the University of Canberra this week.

The workshop included a presentation by senior midwife and associate professor in midwifery at Nottingham University and author, Denis Walsh, who discussed evidence and skills for a normal birth.

"When women have appropriate support in a loving, nurturing environment, normal labour and birth is achievable for the majority of women," he said.

University of Canberra professor of midwifery and event organiser Deborah Davis said physiological births were about keeping intervention to the minimum necessary "to have a good outcome for mother and baby".

"We're not saying you can't have any pain relief, you can't have this, you can't have that. We're just saying work with the physiology of labour and birth to achieve the best outcome and for us, that's what promotion of normal birth is about," she said.

"Every intervention in labour and birth brings risk. Any sort of pharmacological pain relief has side-effects and has some risk.

''Any time there's forceps ... or a caesarean section, they all carry some risk. Sometimes that necessary – if you need an intervention because the baby is distressed, then absolutely, you have to have that intervention.

"But sometimes there are inventions in childbirth when it's not absolutely necessary and then you're introducing risk to what would otherwise be a normal labour and birth and there are risks for the mother and risks for the baby.

"The risks are small but you just don't want to bring that risk to yourself if you can avoid it."

Professor Davis said Australia had a high rate of intervention in childbirth.

"Every midwife will thank the Lord for caesarean sections when they're needed but we have such a high intervention rate in Australia. The caesarean section rate is over 30 per cent – that's a third of all women are going forward in their lives having had quite major abdominal surgery and that's not good for us," she said.

"It is higher than other countries that have just as good outcomes but they have lower intervention rates. We can do a lot better here."

Professor Davis said it was better for the mother and baby to avoid intervention in childbirth when it wasn't needed.

"For example, if the mother avoids narcotic analgesia in labour, so that would be something like morphine, then the baby is much more alert at birth and it's not feeling the effects of that medication in its body so it feeds better and the woman is much more alert when she's giving birth," she said.