Teens who pledge to stay virgins until marriage are just as likely to have premarital sex as those who do not promise abstinence, and are less likely to use condoms and other birth control when they do, according to a new study.

The new study found that more than half of youths became sexually active before marriage regardless of whether they had taken a "virginity pledge," but the percentage who took precautions against pregnancy was 10 points lower for pledgers.