Do one is questioning why Palin would know in advance that Trig would be a Down's baby? Why would someone who does not believe in abortion make an effort to find out if an unborn baby suffered from Down’s syndrome? We can only assume that Sarah Palin had amniocentesis if she knew in advance that the baby had a birth defect. Since this procedure involves some risk, why would she do this? Or did she have the baby and then say she knew in advance?

'why would she do this?' you ask, as if that were some kind of clever question. Answer: because she knew how old she was. Duh.