Sadly in many cases the baby does not have a chance. If the mother dies the baby more often then not will not make it.
Excellent question. One can point to situations in which a mother chose to sacrifice herself for her child--an unquestionably noble act. However, as a matter of law, the state cannot force the woman to die in that situation, and in banning abortion, there must be a provision allowing for the saving of her life.
Why does the mothers life trump the child's life in a complicated pregnancy?
I'm with Ronald Reagan on this question. It's a matter of self-defense. I'm a man so this couldn't happen to me but putting myself in a mother's place, another person or persons is putting my life in danger. As a matter of Liberty, I have to right to defend myself from the person who is threatening my life, to the other's death if necessary.
Because society can not demand that one person sacrifice himself or herself by being passive when his or her life is threatened.
If the woman desires to sacrifice herself for her child, then that is a completely different matter. But, she should be counseled on the child's chances and no one should fault her for acting to preserver her life.