Companies need people willing to work for the least amount of money possible in order to have the highest profits possible. Desperate people are more likely to accept low wage jobs and stay with low wage jobs. They will also not stand up for workers rights, because they can't afford to lose that job.
Making it more likely that women will get pregnant as a teenager puts them in a more desperate situation so they are more willing to work as low wage slaves rather than try to get an education and better themselves. And their teenage boyfriends, in order to support their accidental children, are then also more willing to take desperation level jobs and not complain about it. (Or to get away from their responsibilities join the army as cannon fodder for wars that profit corporations.)
Because you are making sure they reproduce at a young age you don't need to provide them with health care because you only need them to live long enough for their children to replace them as the new wage slaves.
Meanwhile the general desperation of their lives will drive them towards churches which can then convince them to vote for people who will keep the system in place.
Make contraception nearly universal along with access to abortions and you'd suddenly have non desperate independent people who wouldn't work unless they could get a wage worth their talents and who would also be willing to stand up to unfair labor practices - because they wouldn't' feel like risking their job would be taking food out of their children's mouths.
The way the American economy is run now virtually requires unplanned young pregnancies to survive.