Melbourne, September 27 Poor understanding of reproductive and sexual health is leading to a generation of Australian women vulnerable to several risks, according to an online survey.

Sexual health experts found two in every three women were indulging in unprotected sex, putting themselves at risk of unplanned pregnancies and catching sexually transmitted diseases due to poor sex education.

The research also found that more than half women aged 20 to 34 did not know when their next period was due.

Dr Christine Read, a spokeswoman for Sexual Health and Family Planning Australia, laid the blame on widespread ignorance about sex.

"It's worrying that young women continue to engage in unprotected sex, but it is equally concerning that many women don't have a basic knowledge of their menstrual cycle," The Age quoted Read as saying.

"Many women don't realise they can get pregnant even if they have unprotected sex outside the time they're ovulating," she added.

The researcher said people were less confident in approaching the topic, explaining: "We're a pretty sophisticated society but there are some areas where people are a little scared.

"Parents ... like to be the ones to educate their children, yet we have an awful lot of parents who say to us, 'Gee, I'm scared of approaching this topic and how do you do it?"" (ANI)