This study, known as MARBLES (Markers of Autism Risk in Babies - Learning Early Signs), addresses both the causes and the mechanisms of autism spectrum disorders (ASDs). The aim is to determine the role for two classes of common household chemical exposures, namely pyrethroid pesticides and brominated flame retardants, using an innovative design that maximizes the efficiency of the study. Additionally, MARBLES will explore the role of maternal immune dysregulation and of mitochondrial dysfunction in the newborn as markers of potential mechanisms leading to aberrant neurodevelopment. By addressing both the need to understand risk factors for ASDs beginning during gestation and the need to elucidate underlying mechanisms, MARBLES has the ability to move the field of autism forward towards a more multifactorial and mechanistically driven research agenda. From this study, interventions at the individual behavioral or societal level may be suggested.