I would think that in a placental abruption, the baby is no longer able to benefit from the mother’s body, therefore the only hope of saving baby would be early deliver with (however vain) an attempt to save the life. I would think that the thought process of “We need to get rid of this fetus to save the mother’s life” is evil because there the life of the fetus would be disregarded, thrown away. But in the case of a placental abruption and early delivery, that’s not necessarily the case. If the intent was to end the pregnancy with no thought toward the outcome of the baby – if the mother’s life was the only focus – it would be immoral. But in the case presented, nature has already taken its course. Leaving the baby in the womb would not save him or her, and the delivery is not a direct attack. It would be therapeutic if we had developed the technology to be able to help these babies. On the flip side, a direct abortion “because the baby is going to die either way” would be evil because the death of the baby is intentional, not a tragic side effect of a lack of technology.
I don’t think an early delivery because of a placental abruption, even when the death of the child is inevitable, counts as an abortion. At least, not when the death of the child is unintentional. If one was going with an early delivery just to “get rid of the pregnancy” that may be a different matter. I think mindset and therefore intention matters here.
I don’t know if what I say makes any sense. Been a foggy-brain couple of days.
Edit to add; maybe the early delivery would be the right thing to do on the basis of attempting to get the child out for baptism. If the baby is dying either way and this is absolutely confirmed, it may be the morally better option to get them out so they can be baptized. I don’t really know. Maybe something to think about.