Causes of ASD are evidence based. From a needs assessment survey we conducted as SCAU in Central Uganda, it can be deduced that the causes of ASD are both genetic and environmental.
Genetic causes are associated with trans-generational histories of autistic families, however environmental factors are the more common autism precursors .

The commonest of environmental factors include prematurity and low weight births. Prematurity is attributed to antenatal health and body effects on the mother such as maternal illness, accidents and much exposure to pesticides or air pollution as well as parents’ advanced age. ASD can result from childbirth difficulties, which usually lead to oxygen deprivation of the baby .