We had other names picked out for our baby until we found out he had trisomy 18. We found out at our first ultrasound (19 weeks), not the condition, but that there were so many things about him that were "incompatible with life." Once we found out all the issues we asked to know the sex, too, because we figured we knew everything else about him... We almost immediately and unanimously named him Emmanuel. It means "God is with us." We were so convinced that God was in our pain with us, even crying with us, it was such a comfort. We also knew that God was with our baby, he wasn't alone in there and that was a HUGE comfort. Our baby lived another five and a half weeks.
Sadkitty, I know what you mean about using a name. I mostly just call him "Baby" or "our baby" when I think about him because this is how I addressed him when I spoke to him, even after we picked out a name. It's almost more personal for me because that's my (horribly unoriginal) nickname for him.