I understand your point and it's a valid one, but you're not actually engaging with (part of) parent's argument.

If I'm a parent of a small child, and I decide to completely stop feeding it, and they die, did I do something morally and/or legally wrong? I think most would answer yes on both fronts. So the question is, is there an inherent difference between these two situation?

How does a 39 week old fetus differ from a newborn? I think the point of contention for most people is on why a mother should be able to end the life of one and not the other.

The majority of Americans do not support elective abortion at 39 weeks, so that means by definition they support some regulations. In other words, there has to be a line drawn somewhere. The question is, where?