1. Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
2. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia
3. Autism Research Program, Kaiser Permanente Northern California Division of Research, Oakland, California
4. Wendy Klag Center for Autism and Developmental Disabilities, Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
5. Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, Colorado
6. Center for Autism Research, Children’s Hospital of Philadelphia and Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
7. Department of Psychiatry, University of Colorado Anschutz Medical Campus, Aurora, Colorado
8. California Department of Public Health, Environmental Health Investigations Branch, Richmond, California
9. School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania