I suppose the same could be said about a young single mother with a baby. If she can't take care of the child, maybe she should give it up. Of course, "giving up" a child is different than abortion. One cannot abort a child outside of the womb (murder), why should should abort one from within? And don't you think if she did attempt to kill the child, that others might want to intervene to save the child? See, it's not so different after all. Who is the advocate for the unborn child? It certainly can't just remain exclusively with the mother could it; any more than it could for a mother with child outside the womb? Why is location the only determining factor here?

I suppose you could look at it from a number of different perspectives. If the woman's life is truly endangered from the fetus, you could look at it from the point of view of self-defense and evict the fetus. This would then potentially kill the unborn child. That's more justifiable. As far as I know, you typically cannot remove the child from the womb at any point in the development of the child and not severely risk it's life.

Nevertheless, it seems we should be weighing the life of the mother against the life of the child in a worst case scenario (imminent threat). The question should be one of eviction, trespass or self-defense not abortion and death irrespective of action and consequence. A proportionality of force thru action is key.

Just as in life outside the womb (analogy), evicting a person from "off of" or "out of" a location, you must use proportional force. For example: if a child wanders onto my property (it doesn't matter how he/she got there actually), I can't just shoot to kill. I could probably escort the child to the edge of my property with a stern warning to not trespass again (assuming he/she would even understand such a request) but that's about the sum total of it.

I know that a child on or in a property, and one inside a woman presents a clearly different environment, but the child within the womb really doesn't have the opportunity to be "free of" the mother until a certain point in its development.