For a long time autism was thought to be more prevalent in boys than girls at a ratio of 4 to 1.
This has been reducing over time and this recent study indicates that in Sweden the ratio is almost indistinguishable.
www.bmj.com/content/392/...
bmj.com
Time trends in the male to female ratio for autism incidence: population based, prospectively collected, birth cohort study
Objectives To examine changes in the male to female ratio in diagnoses of autism spectrum disorder (ASD) over a 35 year period, providing temporal trends in diagnosis (incidence rate), the male to fem...
