Once upon a time, when there was little or no effective contraception or protection from STDs, sex could easily result in unplanned pregnancy, illness, or death. But obviously, pregnancy and disease were intended to punish people - particularly women - for having sex; if you have sex, you *ought* to "fall" pregnant or "fall" ill. If teenagers use contraception, they avoid the punishment they're *supposed* to be getting. (This is also why some pro-lifers say abortion is acceptable in the case of rape or incest: women should only be punished if they *wanted* the sex.)

I'd also like to know who's having unprotected sex with thirteen year old girls. I *hope* mostly it's thirteen year old boys, who are probably just as immature and ill-informed. But I have my doubts.