Are we talking about individual incidents or the overall impact on the economy?
The health impacts of contraceptives are insignificant compared to the benefits.
To put it another way, look at how expensive kids are in the developed world. Now think about handling that expense when you are part of the extreme poverty bracket. The economic benefit of not having kids when you don't want them is huge.
Right, there are no negative side effects to taking birth control, like increased risk of heart disease.