Something obvious about abortion

I occurred to me yesterday while I was running: if you believe that this life is only a small part of our existence and what really matters is where you go after you die, then isn't abortion of a child the best way to go? I mean, think about it: there are not a lot of Christians who would argue that Children can go to hell. So of all the children that have been aborted, 100% (from the theological perspective) have gone to heaven. What percentage would have made it if they had lived to be 75 or whatever? It seems like the most humane thing would be to abort a baby rather than risk it going to hell. What am I missing here?