From ScienceDaily - "An examination of the birth records of the more than 7 million children born in the state of California during the 1990s and early 2000s has found a clear link between the month in which a child is conceived and the risk of that child later receiving a diagnosis of autism."
The researchers suggest that this study is viewed as a starting point for further inquiry to determine exactly why children conceived in December, January and February are at a greater risk of developing "full syndrome" autism than children conceived during non-winter seasons.