For such sentences, I ask how would you blame someone who was raped? Would you force them to have and keep the baby?
I'm never in favor of forcing anyone to do anything.
Our sense of morality does not condemn all killing; only unjustified killing--like killing in self defense. So killing a fetus that poses a risk to the mother would be a justified killing; the mother killed in self-defense.
I don't think that killing as a method of birth control is a justified killing. If a woman wants to control her own body, then she should keep her knees together if she doesn't want to risk having a baby.
Killing to remove the consequences of rape is a little more of a gray area. If the mother was strong enough to appreciate the creation of life without being adversely affected by the events that resulted in a new life, I think it would be great if she were able to carry the child to term, whether she chose to raise it herself or chose to let it be adopted. But I can also understand how the killing might also be a form of self-defense against severe, harmful, and even debilitating psychological reactions to the circumstances of the conception.
If we really wanted to end rape, though--or at least severely curb it--we should go back to the Biblical consequence for rape laid out in Deuteronomy 22:28-29. If a man rapes a girl, he has to pay her father a hefty dowry, and then he has to marry her for the rest of his life--without the possibility of divorce.
I can guarantee that if that were the consequence for rape, occurrences would drop to almost zero. Who wants to risk THAT kind of punishment?