How about just extracting it and seeing if it can survive with some help?
If not, well, there you go: abortion but without that sickening process of a doctor rushing to bash its skull in.
If so, then thank God we didn't crush the skull of a viable human child.

That is the problem with the skull-bashing portion of this procedure. Since I can't see any possible benefit it offers to the mother, the only reason I can think of for doing it is to make damn sure that the baby dies; to remove any chance that a viable child might have been born.
If it is actually necessary to save the mother, and someone can explain to me why, I'm certainly willing to reconsider (saving the child by killing the mother hardly seems wise). But so far I can't for the life of me see the point to it except to make absolutely certain that the baby dies, and to do it at the last possible second before the existing laws protect it.