A new study has revealed that mothers who take folic acid, iron during pregnancy have smarter kids.

In developing countries where iron deficiency is prevalent, prenatal iron-folic acid supplementation could increase intellectual and motor functioning in offspring, according to researchers from the Johns Hopkins Bloomberg School of Public Health.

They examined the intellectual and motor functioning of children in rural Nepal and found such micronutrient supplementation during pregnancy positively impacted working memory, inhibitory control and fine motor functioning in the school-aged children.

"Iron is essential for the development of the central nervous system," said Parul Christian, lead author of the study and an associate professor with the Bloomberg School's Department of International Health.

"Early iron deficiency can alter neuroanatomy, biochemistry, and metabolism, leading to changes in neurophysiologic processes that support cognitive and sensorimotor development," she added.

Christian's team studied 676 children, aged 7 to 9 from June 2007 to April 2009 who were born to women in a community-based, double-blind, randomized controlled trial of prenatal micronutrient supplementation between 1999 and 2001.

Study children were randomly assigned to receive daily iron, folic acid and zinc, or multiple micronutrients containing these plus 11 other micronutrients.

All received vitamin A, as did a control group of vitamin A alone from early pregnancy through 3 months postpartum.

The researchers assessed intellectual functioning using the universal nonverbal intelligence test (UNIT) and motor function was assessed using the Movement Assessment Battery for Children (MABC).

They found that maternal prenatal supplementation with iron and folic acid was positively associated with general intellectual ability, some aspects of executive function, and fine motor control compared to offspring of mothers in the control group.

"This innovative study shows that in very low-income settings, children's cognitive performance is influenced by their mother's iron + folic acid status during pregnancy, along with school attendance, illustrating the importance of both nutritional and environmental interventions," said Maureen Black, professor of pediatrics at the University of Maryland School of Medicine and an adjunct professor with the Bloomberg School's Department of International Health.

"Few studies have examined whether micronutrient supplementation during gestation, a critical period of central nervous system development, affects children's later functioning," said Christian.

"Considering the significant role of iron and folic acid in the development of both intellectual and motor skills, antenatal use per international guidelines should be expanded in many low and middle-income settings where program coverage continues to be poor," she added.

The results are published in the current issue of the Journal of the American Medical Association.