Do teenagers really need to be encouraged to have sex? An absence of discouragement should be sufficient, for mutually attracted pairs.
High-availability abortions and contraceptives given out in schools are just examples of governments giving people what they want. However many in the anti-abortion and abstinence movements are engaged in an ambitious social engineering effort, telling teens to resist their strong biological urges to have sex, in favor of marriage and monogamy, because they believe this leads to a more spiritually healthy outcome, long-term.
There is surprisingly little innovation in this space. It's taken for granted that teenage-pregnancy is a bad word, that 30-40 year olds make better parents because they have more money. Society could choose to support early marriage and childbirth. Parenting requires a lot of energy, something that youth have in abundance. Also, young people remember what it's like to be a child, and make more empathetic parents.