Teen pregnancy increased astronomically with the advent of "sex education".
I think it's safe to say it does nothing whatsoever to reduce the incidence.
That is completely false. Even study that has investigated abstinence-only education has found higher teen pregnancy rates, higher transmission of STDs, and increased abortions. This is factual reproducible evidence. No, your unsupported hunch backed by the credentials of having possibly spawned a child yourself does not refute every verified scientific study on the topic.
Planned Parenthood is one of the most knowledgeable organizations with regards to sexual education. If they were there just promoting abortion, I think it's safe to say that the message would be strongly inappropriate, but I have yet to hear any evidence of this being the case. They were teaching sex-ed, just as any middle-aged manly female gym teacher would have done, but they were in a much better position to answer questions.
Teenagers are teenagers. If you are so foolish to believe they can't figure out what SEX is despite raging hormones and modern media, you are denying their biology and intelligence.
It sounds to me the issue isn't that kids were learning about safe sex topics, but that the name "Planned Parenthood" pissed off a lot of unthinking soccer moms.