The statement in question uses a form of logical fallacy known as the "drawing the line" fallacy or the "tu quoque" fallacy. This fallacy occurs when someone dismisses another person's argument by pointing out a perceived inconsistency or hypocrisy, rather than addressing the argument itself.
In this case, the writer of the letter to the editor is accusing Andrea Keene of selective morality because she expresses her opposition to abortion but not fertility drugs. The writer then suggests that if anti-abortionists consider abortion to be morally wrong, they should also consider fertility drugs as morally wrong, due to the potential harm caused to the infants involved.
However, the fallacy lies in the fact that the writer dismisses the argument against abortion by shifting the focus to fertility drugs. This is an attempt to undermine the argument by drawing a line of inconsistency, rather than addressing the argument directly. Whether or not the writer's claim about the moral equivalence of fertility drugs and abortion is valid, it does not negate the argument against abortion itself.
To avoid falling into this fallacy, it is important to address the argument at hand and evaluate its merits independently, rather than attempting to undermine it by pointing out perceived inconsistencies or hypocrisy.