When these women speak of "forced birth," it is possible that unspoken is their assumption that they had no way to refuse the sex that would lead to an unplanned pregnancy. The birth isn't "forced" but the sexual intercourse is (not necessarily actual rape, but coercion or peer pressure or societal "norms" to be part of the "hookup culture"), however, they dare not say that. Too risky. Far too risky.
Even if that were the case, if women are sexually active because of peer pressure, why aren’t they being responsible and using birth control?