HealthDay News) -- Low folate levels during pregnancy are associated with higher odds for attention-deficit/hyperactivity disorder in offspring aged 7 to 9, new research has found.

The findings seem to support the long-held belief that folate (folic acid) levels in expectant mothers influence their children's nervous system development.

The researchers also found that children of mothers with low folate levels had notably smaller head circumference at birth, which may indicate a slower rate of prenatal brain growth.

The study was released online Oct. 28 in advance of publication in an upcoming print issue of the Journal of Child Psychology and Psychiatry.

"Our findings further support the hypothesis that maternal nutrition contributes to an individual's development, with potential consequences for their behavior later in life," study author Wolff Schlotz said in a news release from the journal's publisher.

The results are special cause for concern in relation to low-income families, where a mother's nutritional health receives a low priority, and women are less likely to take folic acid supplements prior to becoming pregnant.

More information

The U.S. National Library of Medicine has more about folate.