Women aren't being informed about the possible harmful outcomes of a vaginal childbirth, causing long-lasting physical and mental damage.

That's the argument being made by a range of women's health advocates and experts, including the founders of the charity Australasian Birth Trauma Association (ABTA).

While women might be informed about the risks of caesarean delivery they aren't told about the risks of vaginal delivery, which include vaginal and perineal tearing, incontinence, sexual dysfunction and the inability to stand for long periods, according to the group.

One of the founders, midwife and trauma nurse Liz Skinner, says that 40 per cent of Australian women don't progress to vaginal delivery with normal outcomes and are being left behind in our healthcare system.

"They are the hidden ones," she said.

Amy Dawes, another founder, is one of that 40 per cent cohort.

"I was pretty determined to have a vaginal birth. I fully believed that if I did all the right things I would get the birth I desired.

Amy Dawes co-founded the Birth Trauma Association after suffering injuries delivering daughter Eliya. ( Supplied: Amy Dawes )

"I did my pregnancy yoga, I continued exercising, did meditation, and I did a calm birth course.

"I was all set to breathe my baby out. That was pretty far from what actually happened."

Ms Dawes suffered bilateral levator avulsion (where the pelvic floor muscle tears off the pubic bone) and prolapse (a condition in which any or all of the bladder, bowel and uterus fall into the wall of the vagina) among other injuries.

"Women are just not being told of the risks of vaginal birth," she said.

"I've yet to meet one woman who has heard of a prolapse prior to having it."

When complications arise, the physical symptoms can be matched by emotional ones.

"There's a horrible feeling of blame ... that they [are] weakened mothers," said Ms Skinner, which contributes to another trauma some women experience after childbirth: post-traumatic stress disorder (PTSD).

Physiotherapist and childbirth educator Vanessa Shribman said PTSD is affecting a quarter of Australian women who have given birth, a fact that is not given the attention it deserves.

However, she believes the majority of women can have good vaginal births — the problem is they are simply not being supported well enough throughout their pregnancies and labour.

But she says when women have a sense of control — as well as clear information, good support, strategies for pain and respectful care from their health providers — they are likely to feel more positive about their childbirth experience.

Ms Shribman, who runs birthing classes for mothers and their partners in Adelaide, said women are not properly informed about the events that can follow interventions in labour.

Having an epidural, for example, increases the chances of a forceps delivery which can cause terrible injuries.

Since the ABTA launched in 2017, Ms Dawes has noticed a common grievance among the many women she's spoken with.

"When you actually sustain these injuries the biggest question that you ask and that these women are asking is:

"How did I not know that this could happen to me?

"Many of us know the risks that lie with a caesarean section, but we need to have an honest, unbiased discussion in the antenatal period for both birth options."

Sally Tracy, Professor of Midwifery at the University of Sydney, said vaginal deliveries provide significant benefits for babies and mothers.

"Labour is very, very protective for the baby, and in fact it starts off a whole cascade of events in terms of hormones.

"Babies have very high levels of adrenaline and cortisol when they are born vaginally, and we think that this probably kicks off other factors and little metabolic and neurodevelopmental levers," she said.

However, she believes our maternity system is not always well set up to support women during childbirth.

She said research shows that by far the best outcomes are when a midwife who the woman knows and trusts is involved in their care throughout pregnancy, and is also present during labour.

In most cases, this continuity of care is simply not happening in Australia.

Professor Tracy put the figure of Australian women who receive no intervention, such as epidurals or forceps, at all during their birth at only 15 per cent and said the trauma that can follow intervention is "absolutely huge".

She also believes caesarean sections are being done when they are not warranted, and in some cases not being done when most needed.

She said Amy Dawes' childbirth story is "a very, very sad indictment of our system".

"Amy had forceps and she had an epidural and she had all sorts of interventions, which we know are happening to so many women in this country," she said.

"We are not having a lot of luck because the system really isn't set up to do it well, but what we want to do is be able to provide women with much more information about what they can expect in birth.

"It's not so much the mode of birth that matters, it's [women having] some measure of control, where they feel as if what they want in their birth, they are able to realise."

Ms Skinner, who is doing a PhD on trauma during childbirth, has interviewed 40 women who have injuries as a result of labour.

She said there is a tension between what women are told by their midwives and obstetricians about the best way to deliver a baby.

Women reported feeling "that the midwives wanted the woman to wait until...the labour was a bit more progressed and the doctors wanted to take them to theatre and do a caesarean section".

"I think we need to build bridges between midwives and obstetricians," she said.

"Even if something happens, at least they feel like they made an informed choice," she said.

Ms Dawes wants to see more information shared with women in the lead-up to childbirth.

"There's so much focus on the baby but we need to start thinking about the mother as well," she said.

"We know that there's research that indicates what would potentially make a mother high-risk — maternal age, size of baby — and if a woman presents herself at 37 years of age and she really wants a vaginal birth, we need to support her for that best possible outcome.

"But at the same time we need to have a really frank and honest chat about the possible risks.