A previous study showed that teens who had pledged abstinence waited a bit longer to have sex, but that when they did (which they did at the same rates as those who had not taken any such pledge), they were much more likely to be "unprepared" -- i.e. no contraceptives, including STD-reducing condoms.
so its either unprepared when young or unprepared when old.
It only tells me that preparation for older studends is better when they have matured rather that when they have yet to hit their teens.
Who sponsored this study? Abortion providers of america?
It's sort of the worst of both worlds: abstinence pledges don't really work, but when the kids actually have sex, they don't use adequate protection.
Teenagers will have sex. Always have, always will.