In her 50 years of delivering babies, Caroline De Costa has not only witnessed change, she's propelled it.

She's Australia's first female professor of obstetrics and gynaecology. She studied her medical degree while pregnant and as a single mother. And she was instrumental in the fight for women's reproductive rights in Australia and in Ireland, even smuggling IUDs and condoms into Dublin.

Professor De Costa has been on the frontline of women's fight to control their bodies for decades.

And while she's optimistic about how far we've come in women's health and obstetrics, there are still some changes Professor De Costa would like to see.

Smuggling IUDs in the fight for reproductive rights

In 1964, when she was 17 years old, Professor De Costa started studying medicine in Sydney. At the end of her first year, she felt unsure about becoming a doctor so she took a break to go travelling.

She was interested in Europe but getting there was expensive. So, at a pub one night when a New Zealand deckhand mentioned the Swedish ship he worked on employed women, she was in.

Professor De Costa worked as a dishwasher as she sailed around the world. Then, using the money she'd earned, she continued travelling, before settling in Dublin.

There, she continued studying her medical degree.

In her first year there, she became pregnant, had her baby son and then became a single mother.

It didn't stop her graduating.

After her own pregnancy and over the course of her medical training, Professor De Costa became determined to improve women's reproductive health access.

"I saw what was happening to Irish women who had no contraception [it was illegal in Ireland at the time], no control over the number of pregnancies they went through and there was no abortion," she tells ABC RN's Life Matters.

"I became part of a movement to try to change that."

At the birth of her son Jerome, Professor De Costa had been assisted by a "wonderful obstetrician" who would take no fee. Instead he asked for her help to smuggle intrauterine contraceptive devices into Ireland. It was not available there but it was available in England, where medical students regularly travelled.

"Because if he was caught doing that, he would be prosecuted and deregistered. Whereas as a medical student, I'd simply have them taken off me and be scolded," Professor De Costa says.

"So I did it about 20 times, bringing back copper intrauterine devices. I was never caught. And I was very glad that I could do something for him," she says.

'We don't train women'

As a medical student, Professor De Costa had watched the safe delivery of a breech baby and been impressed. By the end of her medical degree, she was determined to specialise.

And barriers there were.

Professor De Costa was "very well supported" in Ireland and says during the undergraduate and specialist training she completed there, "nobody ever suggested that I could not have obstetrics as a career or that I could not have children as well".

But when she came home to Australia, it was a different story. "It was a hospital here in Sydney where I applied to become an obstetric registrar back in 1974, and I was well qualified. I had passed the necessary exams of the London college," she says.

"And I was simply told, 'We don't train women in Sydney'."

Women had been able to train during World War II while men were at war. However, from when the men returned until the early 1980s, female students were "very much discouraged", Professor De Costa says.

She decided to return to Ireland to complete her specialist training, but brought what she'd learn home to Sydney, where she started practising in the 1980s.

She also brought home a determination to improve reproductive choices for women.

She began lobbying for the right to abortion and the right to access the medical abortion drug RU486 in Australia.

At that time, although abortion was illegal in New South Wales, it was possible for women in Sydney to access surgical abortion "relatively easily and it was not terribly expensive", she says.

But then RU486 was made unavailable to Australian women, when a federal bill prohibited its use, with "not a thought for women's reproductive health", Professor De Costa says.

"[The bill] was passed in 1996, and it was impossible for Australian women to have a medical abortion, which was increasingly available overseas, under this legislation."

Professor De Costa had witnessed first-hand the impact of this legislation.

She recalls treating a woman in Far North Queensland who'd had two very complicated pregnancies, and was pregnant for a third time. The woman wanted an abortion but couldn't get one.

"That particular pregnancy ended in a very early caesarean section, which I performed, and the birth of a very much affected child who died. And about six weeks later, I saw [the woman] postnatally, and she was recovering, but she was very bitter about the whole experience," Professor De Costa says.

"That triggered my finding out more about medical abortion."

She travelled to the US, where medical abortion was available, to learn more. She returned "convinced that I really had to try to make it available for Australian women".

She campaigned alongside many female and male senators, doctors, supportive organisations and members of the public. It was a huge effort – and eventually it paid off. In 2006 the bill was overturned.

In with ultrasounds, out with toads

Across Professor De Costa's decades-long obstetrics career, she says the biggest change has been the use of ultrasound technology.

There was no such thing when she was in her final year of medical school in 1972.

"To work out the presentation – was this baby coming head first or breech first – rather than using ultrasound, you had to palpate the woman's abdomen. And mostly, with experience, you were right. But sometimes you were wrong," she says.

She says there "wasn't a great deal of science" in obstetrics in the early days of her career.

"Although the fetus was just a few centimetres away from our fingertips, we really had no idea what was happening to that developing child."

Another significant change Professor De Costa has experienced relates, surprisingly, to amphibians.

"When I first became pregnant, the way the diagnosis of pregnancy was made was by giving a specimen of early morning urine," she says.

That part isn't so different from today. But what happened next is.

"Some of this urine, mixed with alcohol, was injected into a frog or a toad," Professor De Costa says.

The urine of pregnant women contains hormones which affect the reproductive organs of women – but also of frogs and toads.

The injected frog or toad would then be inspected later in the day and any change in its reproductive organs "gave a very good indication of whether the woman was pregnant or not".

Today, home pregnancy tests are "much better and more private but they are actually testing for the same hormone", she says.

It's one improvement of many. Professor De Costa speaks positively about the progress – and the future – of women's reproductive health.

But there's an area where she'd like to see Australia shift its attitudes: the use of intrauterine "long-acting reversible contraception".

"In Australia, the uptake of these – although they're very safe, even for women who've never had a pregnancy – is not very high," she says. And yet, "they give women a lot of control".

"If [uptake] was higher, I believe there'd be less need for the provision of abortion for unintended pregnancies," Professor De Costa says.

"Sometimes it's hard to remember to take the pill. If we've got gastrointestinal upsets, the pill doesn't work. And you're having to take a pill every day, it is more demanding than having an intrauterine device fitted, which will last for three or five years.

"So I think moving towards the long-acting contraception is something that we need to push harder in the provision of reproductive health care for women in Australia."