The thing that will save the world from overpopulation- the internet. Both as a source of information, and perhaps as a way of abstracting social interactions that otherwise would have more opportunity to be acted out in sweatier ways.
A while back I saw some study said that said women who grow up with a TV in the house have on average, 1 less child than their mother. And this was holding even as we go into the 3rd generation of kids with TVs at home. The Internet, and especially mobile Internet, are like TV * 5. So maybe this is right.
"The secret sauce of influence is the telenovela's subtle promotion of extravagant materialism by means of a smaller family as opposed to the relative poverty of large families. It's also had the effect of promoting urban lifestyles."
I don't know how directly relevant this is to teenage pregnancy, but there does seem to be evidence for media consumption affecting reproductive outcomes.
[1] http://www.theatlantic.com/international/archive/2012/06/how...