When the mother's life is at risk person abortion becomes much less repugnant. No one reasonably argues otherwise.
I am suggesting a comparison between two treatments where the treatment that saves the fetus also provides the woman a better chance of survival. Normally people can choose whatever procedure they want, they may choose one that medically doesn't seem better but for their own personal reasons they wish to go that route.
Doctor says treatment 2 = you are more likely to live, baby is OK
Doctor says treatment 1 = worse for you and baby dies.
A woman should still be able to choose treatment 1 just like some people may choose homeopathic treatments over the traditional methods which show better survival rates.