We find out, mainly because of DH. I don't mind finding out, but I'd also be happy with waiting. Actually, I'd prefer to not have any ultrasounds at all, but I have to deliver at a hospital (rather than at home) because of medical problems, and my OB's office requires one at around 18-20 weeks. As long as I have to have the ultrasound, I figure I might as well get something out of it.