It is exceedingly rare for a woman to have a condition that means she "has to" kill her child to survive.
Doctors tell women all the time that this is a possibility when it is not. For one, they have liability laws to deal with and don't want to be held accountable when/if something goes wrong.
Most of the time, according to my info, doctors will let the pregnancy progress to some point where the child could live outside the womb, then do a C section, but I'm not sure on details here... In any case, I wouldn't want murder on my conscience or anyone else's.