Young Australian women are as unlikely to have an abortion today as their grandmothers were half a century ago, according to new national data that shows a dramatic decline in the procedure.

Researchers behind the major findings credit increasing condom use and the nation's newfound enthusiasm for having children for the remarkable new trend.

Findings from a study of women's reproductive history has found that less than five per cent of women born in the 1980s have had an abortion - a significant drop from the 14 per cent seen in women 10 years older.

"We've plotted a sudden decline in the abortion rate that is so low it harps right back to the time when abortion was illegal and rarely practised," said Dr Julia Shelley, of Deakin University in Melbourne.

"That means that a young Australian woman these days is about as unlikely to have an abortion now as her grandmother was back in her day."

Dr Shelley presented new data from the landmark Australian Longitudinal Study of Health and Relationships at the International Congress on Women's Mental Health in Melbourne today.

The study involves about 4,500 women of all ages whose reproductive history was mapped over their lifetime.

Women born before 1945 had the lowest rate, below five per cent, but this increased rapidly with the legalization of abortion, the sexual revolution and the pill.

"It continued to rise for each subsequent group of women who were born later but what we've seen is a dramatic downturn for the latest group of women enlisted, born between 1976 and 1990," she said.

Dr Shelley said while these women were still young, they were past the 20 to 25 peak when women were most likely to abort.

She said the findings were surprising, extremely significant and likely linked closely to changing attitudes to safe sex.

"Widespread sexual education trailed the sexual revolution by some decades and I think the effect of that only more recently cut in and change practices," she said. "But probably more significantly, the occurrence of HIV and AIDS has vastly increased condom use which has the side effect of stopping unwanted pregnancies."

It was also possible that the drop could be linked to the recent rise in the birth rate, seen mostly among older women, the research says.

"If women generally are now more willing to have babies if they fall pregnant then it may partially explain the fall in abortion among younger women."

She said the findings were in stark contrast to the picture of booming abortion rates painted by state and federal politicians over the past decade.

Source: AAP Newsfeed, 19 March 2008