Risk factors
There is no single known cause for ASD. Rather, evidence suggests that there are many factors involved in the development of ASD. Researchers are actively exploring the roles of various genetic and environmental risk factors.
Genetics have been found to play a significant role in the development of ASD. Evidence indicates that siblings of individuals with ASD are at an increased risk of developing ASD themselves.
In addition to genetic factors, a number of environmental factors have been found to increase the risk of developing ASD. Many environmental risk factors consist of prenatal exposures, including maternal contact with high levels of air pollution, maternal viral and bacterial infections and maternal ingestion of some prescription drugs including selective serotonin reuptake inhibitors, a type of antidepressant.
Birth complications involving oxygen deprivation are also associated with an increased risk of ASD.