In some Middle-East societies, when a woman is raped, her family kills her. This cleans the family honor and shame. In the West, we find this barbaric, cruel and medieval; after all, the woman is just a victim. So, we don't kill the woman here. We kill the baby.
And our reason for the killing is more sophisticated: we don't call it "honor" or "shame," we call it "psychological damage." So the baby — the most innocent of the victims — pays with his or her life; while the rapist gets a few years of prison, at most, plus psychiatric treatment (it was not his fault after all, it was society's). And the woman? Don't worry about her, she'll be fine after the baby is dead.