Punishing someone for driving drunk is based on their behavior, not their state of being. Anyone who drives while intoxicated is subject to the same risk of legal discipline as the next person. Punishing a pregnant woman for doing what would otherwise be completely within her rights - if she weren't pregnant - is inherently discriminatory. It would create a completely different legal standard for women of reproductive age than for anyone else. As has already been noted, individual women discover pregnancy at different stages, and NO woman - in the history of time - has ever been cognizant of the exact moment that her pregnancy began. It's impossible to know for a fact that you're pregnant until, on average, you've been pregnant for 2-3 weeks.

So, when do we punish women for crimes against their own pregnancies? When they become pregnant, or when they become AWARE that they're pregnant? If the latter, how do we prove that any individual woman was aware of her pregnancy when she drank, smoked, or drove? If the former, how do we avoid subjugating ALL women, age 11 though menopause, under the assumption that they may be pregnant even if they have yet to realize it?

Can of worms much?