I'll be the voice of dissent, here.

We didn't have sex education at ALL in my high school. Not a word. We didn't even have the little filmstrips in e-school that explained what parts boys have and what parts girls have or why we menstrate

Yet none of us, as far as I know, are still unaware of what a penis is or where babies come from. Because our school left it up to the PARENTS. I firmly beleive this is where sex ed should come from. I'm not sure if the local church had any programs (I wasn't a member). All I know is that I don't remember a single teenage pregnancy in my high school that wasn't within a marriage (and yes, kids did get married in my high school, it was a farming community and kids often left school early, got married, and took over their parents farms).

I had my reunion about a year ago, and not a single one of those couples was divorced. Not a single one regrets it. We talked about how different our school was than those of others we met after leaving town, and all agreed that if we'd been taught sex ed we probably would have been having sex. Granted, most of us didn't wait until marriage, and I don't see a problem with that. But it DID cause us to wait until we were significantly older and able to make more mature decisions.

Disclaimer: Okay, I realize that 400 person high school in a farming town is going to be significantly different in culture than a big city, and perhaps the results of our non-education would have been different in a larger city. I'm only speaking from my experience.