On one hand, I don't see anything wrong with this. These kids are like 15 or 16, so some of them have probably already had sex. I'm sure at least one of their classmates has gotten pregnant by now, too.
On the other hand, my high school teachers had the foresight to send out permission slips before each of our sex ed classes*. And this teacher had to have known somebody was gonna object to this.
*I say "classes" because my school district teaches sex ed twice. We got all the clinical reproductive stuff in middle school, then we got all the abstinence and birth control stuff in high school.