The church should also take responsibility for teaching responsibility. I try to do this to some extent in confirmation class. Since parents and the church have not fulfilled their responsibility in this area, and since a good deal of the information that we pick up from peers is simply wrong, the school has to assume a certain level of responsibility. When I was in high school it was done in health class by the coach. When I was in junior college we had a segment on human reproduction in Biological Sciences.
School can do a good job of teaching the physiology of sex.
It, however, isn't a very good venue for teaching the ethnics of sex. He has given us the ability to prevent to some extent conception, and expects us to use the knowledge wisely. There are some times when a woman should not have a baby for any number of reasons including her own health. There are considerations of spacing children. I personally advise the young couples for whom I perform marriages to wait at least a year before having a baby, because they need the time to adjust to one another, and that means that they will have to use some form of birth control.