I find this highly unlikely. The USA may lead the world among industrialized nations, but there's no way it is the overall winner. (If that's the right word.)
I find it quite likely. In the US, we have different attitudes about conception control than others in this world. I'd say that we rely much, much more on abstinence-only sex education than the rest of the world, especially in Europe.
As we've famously seen a few months ago, teen pregnancy often results from the mixed messages kids get.