With a big teen pregnancy problem why are more schools not teaching sex education?

Ignoring the Facts. The Office of Adolescent Health, part of US Dept of Health & Human Services, has gr8 website devoted 2 facts on teen health, incl reproductive health. Some facts reported: (a) States that teach kids only 2 abstain from sex have highest rates of teen pregnancies. (b) Abt 50% of all STDs diagnosed each yr R in teens! http://www.hhs.gov/ash/oah/adolescent-health-topics/reproductive-health/index.html .
Politics. Voters tend to have very strong personal feelings about where sex education occurs, at home and controlled by the parents vs at school where the topics are managed by a school board and individual teachers. Some people think sex education means teaching abstinence, for others it means teaching birth control and std prevention. All you can do is advocate your position and vote.