That purpose is pretending that the immediate cause of the baby's death isn't worthy of legal or moral attention. Which permits you to treat the body of a pregnant woman as permanently under the control of the state.

>For example (Total Hypothetical for conversation's sake): What
>if Jones was babysitting your child and had taken your child
>with her to instigate a fight and the child was shot and
>killed. Who would you believe was the cause for the shooting
>death of your child, the shooter or Jones?

The person who shot my baby would be the person that caused my baby to be shot.