The swinging 60s were a time of cultural and sexual revolution. Women had access to the pill and by the end of the decade, the first legal abortions would be taking place in Australia.

And young Sydney woman Caroline de Costa, who at 17 had deferred medical school to travel the world working aboard a Swedish ship before settling back into her studies in Dublin, was pregnant.

"Once I was there, one of the first things that happened to me was that I became pregnant because there was no contraception. Well, that wasn't entirely the reason but that was one of them," she laughs.

Contraception - as well as abortion - was illegal in then-staunchly Catholic Ireland.

"Most Irish women would have to go to a mother and baby's home or they got married quickly. Or they had to go to England to have an abortion. It was a terrible shame," Professor de Costa says.

While her baby's father was not involved, her own family back in Sydney were incredibly supportive and with the help of friends, she gave birth.

"I became a single mother - and was for the first four years of my six years of medical school," she tells AAP.

"I saw the poverty people were living in, in that time, particularly women, and how disadvantaged women were by not having contraception and not having control over their reproductive health.

"I became quite motivated about that and that's when I decided I wanted to do obstetrics."

Perhaps it was kismet that her situation drew her attention to the dire predicament faced by Irish women fighting for control over their bodies and their futures ("it wasn't the angel Gabriel who was making them pregnant") just at a time when she was selecting what area of health to specialise in.

In choosing obstetrics and gynaecology, Prof de Costa combined her passions. She would eventually become Australia's first female professor in the field.

But it didn't come easy.

After training in Dublin and Papua New Guinea, she returned to Sydney to sit her exams with the full expectation she would get a job in obstetrics, only to be told: "We don't train women in obstetrics here."

"There's a photo of the first council of the (Royal Australian and New Zealand) College of Obstetricians and Gynaecologists (RANZCOG) that shows about 16 or 18 men on the front steps of the building, all in suits and ties smiling at the camera," she says.

"Not a woman in sight."

After completing her training, she returned once again to Australia to become one of a small number of women blazing a trail in the field in the 1980s but they had to "push and push" for more women.

These days, about 85 per cent of the specialists in the field are women.

"Now we have to wonder about how to keep blokes in," she adds.

Prof de Costa will deliver a keynote address at this year's RANZCOG conference, reflecting on the changes witnessed during her career.

When she started out, the only way she could establish what was happening in utero was to 'palpate' the mother's belly.

Then came the advent of ultrasounds and later 4D 'livestreaming' from inside the womb.

Procedures can now be performed on the baby while still in the womb, and non-invasive prenatal testing using maternal blood can give doctors a clear idea of the baby's genetic make-up before birth.

"I have no idea how they do this at the laboratory but they do and they can tell you accurately what the baby's chromosomal picture looks like," Prof de Costa says.

"There's so much more information about the foetus and the foetus's wellbeing, which was unimaginable when I started out.

"It was not a science when I was first learning about it. It was an art."

Too much information can be a dangerous thing, though, she warns, referring to the growing trend for non-medical ultrasounds in the era of the "designer baby".

"We may reach a stage when you can get a chromosomal print out of your baby at 10 weeks old - down to knowing if their eyes are brown or blue.

"We haven't had the discussion about what people will do with this information.

"Are we going to use abortion if we decide we don't want a foetus that looks like that?"

While she worries about some potential motivations for abortion, she is far more concerned about a great number of Australians whose access to the service is limited.

For non-surgical abortions, women must speak to a doctor with specific training - but a large number in rural and regional Australia do not do that training.

If they have to have surgical abortions, it often involves travelling great distances and paying for accommodation as they recover, which can be prohibitively expensive.

More frustrating are the religious hospitals who refuse to grant abortions - or prescribe contraception.

"They are getting public money to provide public services which they're not doing," Prof de Costa says.

Women should have access medical services that let them claim their lives, she adds, pointing to the changing of the tide in the US, where abortion is again being criminalised in several states.

"If these women don't have safe legal abortion they will try unsafe illegal abortion," she says.