UC Davis is one of four field sites in one of the largest research studies of its kind to investigate early risk factors for autism spectrum disorders. The Early Autism Risk Longitudinal Investigation (EARLI) Study will follow up to 1,200 pregnant women who already have a child with autism. Researchers are studying possible environmental risk factors and their interplay with genetic susceptibility during the prenatal, neonatal and early postnatal periods. The project, one of 11 National Institutes of Health Autism Centers of Excellence projects nationwide, also is investigating early biological indicators of autism.