It's an interesting question. I would say that to be consistent, the pro-life (or as I fondly call them, the forced-birth) crowd would be for punishment for women that do anything that could be said to endanger the fetus.
There are state laws on the books already. In Floriduh, for example, a newborn is tested to determine if the mother has exposed the child to alcohol and/or controlled substances before birth. If the test is positive, child protective services step in. I do not know the punishment for the mother. I'd have to look it up.
These tests are not routinely done. There needs to be a reasonable suspicion of drug use or abuse.