I recommend reading all of Steve Wagner’s article on back-alley abortion, but I wanted to note this section towards the end:
Deal with the More Sophisticated Version
Much of the time, the back-alley concern masks the fact that an abortion advocate is assuming the unborn is not a human being. In other words, she is saying, “It’s wrong to make a surgery more dangerous if it is innocuous.” We can agree in principle, then show that the unborn is a human being and the surgery is not innocuous at all.
Once we’ve made our case, the abortion advocate will likely shift to a more sophisticated argument:
“Even if abortion kills a human being, isn’t it better for fewer people to die (at least we can save the mother)? It is better that at least the mother live, than that she and her fetus should die in the back alley. Isn’t it worse for two to die than one?”
This argument assumes that the mother has no other choice but to kill the child. But, of course, she does have alternatives. As I like to say, she has a third option. It’s not, “Either she kills the child by legal abortion or she kills herself and her child by illegal abortion.” The third option is that she can refrain from killing anyone!