A recent research conducted by Becerra et al. (2014) has found that children whose mothers were born in the Philippines, Vietnam, South and Central America, and Africa were more likely to be diagnosed with Autism compared to the children of US-born mothers. The research revealed that 7,540 children who were born in Los Angeles County between 1995-2005 were diagnosed with Autism. Compared with children of US-born mothers, the risk being diagnosed with Autism is 76% higher in children of African-born mothers, 43% higher in children of Vietnamese mothers, 26% higher in children of Cntral and South America, and 25% higher in children of Filipono mothers. The researchers have also found increased risks of mental retardation coupled with Autism in the children of foreign-born mothers.
Becerra et al. (2014) suggested that there could be a number of factors that could cause the trend that has been found including highly stressful experiences by the mothers, exposure to viruses, trauma or violence. However, they acknowledged that more research should be done in order to investigate different factors that could affect immigration, and identification and diagnosis of Autism.