Most people on either side of this issue don't talk about this much, but I believe that a very large number of partial-birth abortions are conducted because of serious fetal abnormalities that cause the parents to want to terminate the pregnancy.
I feel terrible for anyone who is in a position where they even feel the need to consider PBA. It's a brutal and sickening procedure, and I can't imagine the guilt someone would feel after doing it.
Having said that, your example though an extreme case, makes me think that there is some merit to including a reasonable exception where the life of the mother is at risk. Nothing like the gaping holes that Diane Feinstein and others have tried to include, however.
Oh..........and welcome to FR.
btw, the bill DID include an exception for the health of the mother.
Unfortunately, exceptions for the LIFE of the mother are very different than exceptions for the HEALTH of the mother. "Health" of the mother can and does include "mental health", which opens up a whole 'nother avenue.
PBA's, [as heard from those who perform them (Tiller, et al)], are often performed on girls/women who "don't want a kid right now/can't afford it/forgot, again", and very rarely on those whose pregnancies are "at risk", either by fetal abnormality or risking the life of the mother.