If it's intentional I do agree with imprisonment or some other form of help, but I don't think the article is about that. The article is about harming a fetus as a 'side-effect' of something being used or done without the intention of harming the fetus.
I think that taking crack or rat poison does consitute intentional harm.
When you separate a fetus as a legal entity, which is at the point of viability, it has a right to be protected from harm. Anyone continuing with a pregnancy past that point is a guardian of that fetus' safety, & therefore it's treatment is considered the same as if it had already been born, because if it was born at that point - it should survive.
Baby crackheads don't reflect well on anyone. However, in the cases mentioned, it's unlikely that many if any would go to court because there would have to be a clear intent, or wilful neglect proven. Add to this a defence of hormonal/emotional imbalance, & you wouldn't get many successful prosecutions, though ultimately, an adult child could retrospectively claim for damages inflicted to it in the womb, whatever.
People have been imprisoned & sued for fetal homicide without even knowing that the woman was pregnant, so intention has little to do with it.
It's far better to get rid of laws which only serve to complicate matters, & which lead to innocent people becoming accused.