And with that comes the responsibility of what to do if the mother's life is in danger late in a pregnancy but not in a way exactly as defined as "allowed" in the legislation written by non-medical experts? Even medical experts can't preemptively imagine every possible scenario and write down what should be included in the list.
Here's something I'm sure you haven't thought of before when you formed your opinion on which abortions should be legal.
The issue is extremely complicated to think of in terms of prohibitions.
Read about all those recent incidences where women with clear danger to their lives couldn't receive necessary abortions because their clearly nonviable fetus had a heartbeat while they were bleeding internally.
That's what tying the legality of abortion to the legally defined status of a fetus does, because it's quite impossible to legally define viability in a way which accounts for every possible detail where things can go wrong.
When you leave it to doctors instead, they do the right thing for the vast majority of cases, because they actually do have morals, just like you and I.
smokinjoe