Developmental Pathways and Autism Spectrum Disorders

The application addresses environmental risk factors for autism spectrum disorder (ASD), an identified area of interest for this award. Presently, little is known about risk factors for ASD, including those during the prenatal period that affect the offspring's susceptibility to the disorder. This has created, in our view, a critical barrier to progress in the field. Moreover, in spite of important developmental and genetic contributions to ASD, no studies have investigated how pregnancy risk factors are related to achievement of developmental milestones and to family history of psychiatric disorders. We seek to use a large, nationwide sample including all individuals diagnosed with ASD in Finland and trace the disorder back to effects of developmental exposures on the baby's growth and development. In addition, we will test whether having a family history of a psychiatric disorder increases the likelihood that pregnancy related factors increase risk of autism. The study offers a new and unique combination of advantages including measures of risk factors drawn from blood samples in pregnancy in all subjects, a large sample of children, and comprehensive information on autism diagnoses from both inpatient and outpatient sources. Additional innovative features include data that have been collected and analyzed on prenatal risk factors and growth of head circumference in the first year of life, extensive data on many developmental milestones, and family history of psychiatric problems. Moreover, the study features a large sample size. These aims, in combination, have never been accomplished before in a study of ASD. The study has significant public health impact because it can lead to specific strategies for prevention of environmental insults and the identification of the biological events that lead to ASD. The exposures that have been measured occur commonly during pregnancy and can be reduced with public health approaches. Furthermore, this work has the potential to target infants at risk. We expect that this work will ultimately lead to improvements in current recommendations for care during pregnancy that will prevent cases of ASD.