so, their are documented cases of not knowing their preggo for 9 whole months, (I can't fathom that, but ok). So if she didn't know, drank and smoked cigs, both legal and baby was born still born, then what (this is just for argument sake).
Yes, their is a difference between knowing and not knowing.
Here's another scenerio. A woman drinks the first 2 months of pregnancy but fetus is born with fetal alcholol syndrome, what should be done.