Melbourne, July 7 : A third of Australian women admitted to have slept with six or more men by the age of 25 in a national survey.
The survey also showed that one in 10 Australian women in their late 20s routinely use the notoriously unreliable withdrawal method to avoid pregnancy.
It showed that 28 per cent women have not had a pap smear in the past two years, despite health guidelines urging them to do so.
Dr Jayne Lucke, senior researcher in the school of population health at the University of Queensland, said that 17 per cent admitted they had had a sexually transmitted infection in their lifetime, a 'very conservative' estimate.
The study also showed patterns in contraception use, revealing a trend away from the pill towards newer forms like the vaginal ring.
The data, released at a national public health conference in Brisbane today, revealed that about a quarter of those who were using contraception admitted using condoms alone to protect themselves, a method not recommended by sexual health specialists.
However, Dr Lucke said that even more concerning was the trend towards use of the withdrawal method.
"We found that of the 6,840 women who we interviewed, 10 per cent used the withdrawal method on a regular basis," News.com.au quoted her, as saying.
"That's high and definitely a worry because it really can't be relied on as a means of avoiding pregnancy or a sexually transmitted infection (STI)," she added.
Dr Lucke suggested that while teenage girls and women in their early 20s should be most heavily targeted for sexual education campaigns, women in their late 20s and early 30s were in need too.
"Just because they're getting a bit older doesn't mean they're not at risk as we've shown here. There's still a strong need for good, age-appropriate sexual health services for these women," she said.