100% chance of fetal death to me is the same as non-viable. Idk if that exists in the real world but would not consider delivering a dead child to be an abortion.
My biggest hang-up when you’re talking about late term abortions (when most babies are capable of surviving outside the mother) is would an early c-section or induced labor accomplish the same effects as an abortion as far as preserving the health of the mother? If so, I don’t think it should be up to the mother whether to abort or birth the child if the health risks are a wash. That’s primarily how balancing the interests of the child looks like to me.
Assuming abortion is the only way to prevent the health issues, I personally think any permanent disability (paralysis, unmanageable pain, etc.) that is likely to occur to the mother is an acceptable circumstance for a legal abortion.