Technically, "not aborting" may always cause the mother to die since childbirth always carries some risk. But if you mean a case where the fetus is already dead, I doubt many people would oppose the abortion? What are their arguments? I genuinely can't think of any. Maybe this is just a case of the law being ambiguously written and doctors erring on the safer side?
Which state is that? I thought the strictest laws at the moment were in Alabama, which does allow abortions in the case of a serious risk to the mother's life.