SAN SEBASTIÁN, Spain—Researchers at an international conference on autism Friday presented three new studies lending strength to the notion that environmental influences before birth play a role in the risk for the condition.

In one study, pregnant women who were exposed to certain levels of air pollution were at increased

risk of having a child with autism. Another presentation suggested that iron supplements before and early in pregnancy may lower the risk, and a third suggested some association between use of various household insecticides and a higher risk of autism.

The causes of autism, a developmental disorder that involves social-skill problems, among other symptoms, aren’t well understood but are thought to be multifaceted. Genetics likely account for about 35% to 60% of the risk, many researchers say. But some experts and parents believe that nutrition and other environmental factors may also play a role, especially as the rate of autism in the U.S. appears to have climbed sharply over the past decade.
Read the whole story at the Wall Street Journal