Abortion

[Xiahou]

Of course there is indeed a difference between criminal neglect and intent.
Nevertheless - there are laws against drunk driving for the specific reason that you are endangering other people's lives in a non-acceptable way when you are driving drunk.
If you believe that 2 weeks old cells should enjoy the same legal (and moral) protection as a newborn baby or a 5-months old foetus, you should consequently advocate that behaviour that poses significantly endangers the further development (or even "life") of these 2 week old cells is legally considered to be similar to drunk driving, i.e. forbidden.

I don't want to insinuate that there aren't people who aren't as strongly against drinking/smoking by or smoking in the presence of women who are (even potentially) pregnant as they are against abortion already during the first weeks - however, my subjective impression is that I hardly hear anybody demanding laws that would protect the unborn from the influence of alcohol and nicotine.

How on earth are you trying to compare an unhealthy behavior with a deliberate act? Legislation against pregnant smokers would be to limit an unhealthy behavior. That's different than deliberately killing an unborn baby. You're talking about the government barging into people's homes to make sure they're living an approved lifestyle vs the overt act of killing. You may as well equate a mother smoking around her newborn with one who deliberately drowns her baby in a tub. The argument is a red herring.