You're really only thinking of this from the perspective of someone who doesn't want a child. What if the hypothetical person was a woman who was trying to conceive, whether actively or passively? She might be devastated if she's given a medication that is potentially bad for the fetus and it comes out harmed or even dies. She might have CHOSEN to forgo the medication.
The point is that you need to give the woman the CHOICE if it's a medication needed to improve her quality of life but is harmful to the fetus.
Women need to be more open with doctors if they are TTC. I don't see alcohol being denied to women for any reason; and I don't want to deny pregnant women the right to drink. However, if they give birth to a child with FAS, that in itself is enough proof that they drank too much alcohol and should be punished.