Since 2001, the California Center for Autism and Developmental Disabilities Research and Epidemiology (CA CADDRE) has been one of the largest, most extensive datasets of information on children with autism living in California. CA CADDRE, funded by the Centers for Disease Control and Prevention, is run collaboratively by Dr. Croen from Kaiser Permanente's Division of Research and Drs. Grether and Windham from the Department of Health Services. The CA CADDRE center has also used Kaiser Permanente medical records to investigate autism risk factors during pregnancy and early childhood. This grant will fund several new analyses of this rich dataset to examine risk factors for autism that have been speculated about in the literature. For example, Dr. Croen and her colleagues will investigate the risk of autism from: prenatal exposure to the immunization RhoGAM, which is given to women who deliver a Rh+ baby; maternal illnesses such as infections, inflammation and endocrine disorders; maternal hormone use, ultrasound exams and maternal use of the asthma drug terbutaline; maternal exposure to environmental chemicals, including airborne chemicals and workplace exposure. What this means for people with autism:Data from this study will fill important gaps in understanding environmental risk factors for autism spectrum disorders. Researchers will be able to use the results from these analyses to design future autism studies and, potentially, to design strategies to prevent autism spectrum disorders.