I would say it’s not immoral, and that a mother’s life is worth more than an fetus’s but I would also prefer that other options be available (much in the way I would opt for at least trying other options before having bariatric surgery or other potentially life-changing but elective surgeries).
I remember seeing a movie in (Catholic) elementary school where the mother was going to die if she went through with her pregnancy but did it anyway and it was supposed to show how wonderful and heroic she was and I just thought, “What about her other child? What about her husband? What about her parents? Why are they sacrificing this woman for a fetus that might possibly live? There will be a child (or two) with no mom and a man with no wife and parents with no child because they value this potential over the actual person. I find that view so strange. And yeah.