Iron deficiency has been associated with autism in past studies, such as one published in Pediatrics in 2012. And children of mothers who have too little iron during pregnancy may also have a higher risk of getting this condition.

The search for possible causes of autism has gone in a lot of different directions. But finding a link does not mean finding a cause.

Just as a healthy mother is more likely to give birth to a healthy baby, an unhealthy mother has a higher chance of having an unhealthy baby. A mother with diabetes, for example, may put her child's brain at risk.