There is a word of difference between a baby born so prematurely it cannot possibly live, and an abortion. No matter where you stand on the abortion continuum.
I can understand a woman saying she would never have an abortion under any circumstances. That's the whole point of choice. Some women will choose one thing, others another under the exact same conditions.
A personal example. When I was pregnant with my second child, in my late 30's, I declined testing for Down Syndrome. My ob-gyn was surprised, as was my mother. My husband didn't really express an opinion. I felt that having a child with Down Syndrome was not the end of the world, and I could deal with such a child. As it happens, my son was born without that, completely normal.
If anyone reading this would make a different choice under identical circumstances, THAT IS WHAT CHOICE IS ALL ABOUT.
Another related example. Some years back I knew a woman whose first child died from Tay-Sachs. I knew her because her second child was in my oldest son's class. She was understandably very protective of that child. I cannot recall if she indicated to me if she'd have aborted a second pregnancy, and the child tested for Tay-Sachs, but that's not the point. My husband is Ashkenazi Jew, which means he has a high likelihood of carrying that gene. When I was pregnant with our first, I insisted he be tested for that gene. He was rather offended, but I told him that had I married an African American, I'd have him tested for the sickle cell trait. And if either (one hypothetical) partner tested positive, then I'd have myself tested for that trait. In any case, my Jewish husband did not test positive, and all was well.
Again, others would choose differently, and again, THAT IS WHAT CHOICE IS ALL ABOUT.