Hey there:
no, impossible to tell before birth. My son is 5 and the ped. Is having a hard enough time diagnosing him now as it is. It's all based on his reactions and behaviours. It's taking months.
It is the scariest thing though, eh? (sorry, i'm a cannuck)
i read a book as a teen called sonrise all about this family dealing with their autistic child and it scared the tar out of me too. Or that home makeover episode with the kid who was autistic and blind? Oh, man.
But then, when my son started with the testing, it was a whole different ball game. He's my boy. I've lived with him for 5 years now and having the diagnosis of autistic isn't going to change a thing about my feelings for him. Something I thought would be the scariest thing in the world didn't bother me in the least. He's my precious little man.
~prsmama