Back to Sleep and Autism

We have often wondered if our daughter being on her back so much (Back to Sleep Campaign) had anything to do with her autism diagnosis (PDD-Nos). The back of her head is flat. The Pediatrician felt the only problem would be cosmetically (that was when she was 4 - 6 months old). The skull caps that babies now wear to correct the flat head syndrome were not available then and when they did become available her skull was already formed. Also, when they first went on the market they were not covered by insurance and cost around $4000.00 making it unaffordable for most of us. We have heard occasionally that it is now recommended to have babies sleep on their back but be on their tummy for play. Children tend not to explore their surroundings on their backs. Our daughter crawled on her back like an inch worm and was developmentally delayed. She started to crawl on her knees when she was 1 years old and didn't walk until she turned 2 years old. It seemed that the increase in Autism started around the same years as the "Back to Sleep Campaign" but have not found a lot of research on this as of yet.

I did find this link:

http://answers.google.com/answers/threadview/id/423728.html

I am looking for more research, if you know of any please pass along to me. Thanks!