I've found that "fetuses aren't alive" is a common talking point espoused by people who aren't comfortable sitting in a moral gray area and want an simple excuse to resolve their cognitive dissonance. It's common enough that I can't help but wonder if that is the reason people are so resistant to the idea that fetuses might dream. It seems remarkably similar to "farm animals can't feel pain". A transparent fib people tell themselves to feel better about their positions. Incidentally, I eat meat and I am pro-choice.