I think it's also important to keep in mind that the baptism is an oath taken by the parents, not the child. The parents swear to bring the child up according to the Christian laws/precepts/etc. If the child decides not to stay with that, no harm no foul. That, at least, has always been my understanding.
I never had my daughter baptized, because by that time I'd been out of the church for years. I never got any grief for it from either of my parents, because Mom already knew what was up with me and Dad just figured it wasn't worth arguing about.