A study finds that teens who pledge to remain virgins until marriage are just as likely to have premarital sex as those who do not pledge and are significantly less likely to use condoms and other forms of birth control when they do. According to the study, more than half of youths became sexually active before marriage regardless of whether they had taken a virginity pledge, but that the percentage who used condoms and other forms of birth control was 10 percent lower for pledgers than for non-pledgers.