Pregnant women who lived in close proximity to fields and farms where chemical pesticides were applied experienced a two-thirds increased risk of having a child with autism spectrum disorder or other developmental delay
The related research article can be found here:
Shelton et al 2014 - Neurodevelopmental Disorders and Prenatal Residential Proximity to Agricultural Pesticides: The CHARGE Study
Previous research has also shown links between exposure to air pollution during pregnancy and the risk of autism and related neurodevelopmental disorders. For details, see: Air pollution raises autism risk