TUESDAY, Oct. 11 (HealthDay News) -- Taking folic acid supplements before and during pregnancy was linked to a decreased risk of a having a child with a severe language delay at age 3, according to new research.

The Norwegian study found that women who took no folic acid supplements before and during pregnancy had more than twice the risk of having a child with a serious language delay compared to women who took folic acid supplements.

"Maternal use of supplements containing folic acid within the period from four weeks before, to eight weeks after conception was associated with a substantially reduced risk of severe language delay in children at age 3 years," said the study's lead author Christine Roth, a Ph.D. student in the division of mental health at the Norwegian Institute of Public Health in Oslo.

Results of the study are published in the Oct. 12 issue of the Journal of the American Medical Association.

Folic acid supplementation is already recommended for women of childbearing age, because adequate folic acid stores have been shown to help prevent major birth defects, such as spina bifida and other neural tube defects. Folic acid is important in allowing nervous system cells to reproduce and to repair themselves, according to background information in the study.

In the United States, many foods, such as breads and cereals, are fortified with folic acid. In Norway, flour is not fortified with folic acid, according to Roth.

The study included data from the Norwegian Mother and Child Cohort study, a prospective observational study of pregnant women and their offspring conducted from 1999 through 2008. Data were collected on the children until they were 3 years old.

Mothers assessed their children's language skills using a six-point language scale. Children who had only minimal expressive language, which was defined as only using one word or unintelligible utterances at age 3, were classified as having a severe language delay.

Of the nearly 39,000 children in the study, 204 had a severe language delay.

Of children whose mothers took no supplements during pregnancy, 0.9 percent had severe language delays. Just 0.4 percent of children whose mothers took folic acid supplements before or during pregnancy had severe language delays, according to the study. And, just 0.4 percent of children whose mothers took folic acid supplements in combination with other supplements before and during pregnancy had a severe language delay.

Roth said the researchers don't know exactly how folic acid might help prevent severe language delays, but said it may be due to the nutrient's effect on the nervous system.

"Knowing that neural tube defects range from milder defects of the lower spine to the most severe instances where the fetus does not develop a brain at all, we wondered whether the availability of folic acid in this crucial time of neurodevelopment also could influence other aspects, such as language development," said Roth.

Although many foods in the United States are fortified with folic acid, women who are planning to become pregnant should start taking a prenatal vitamin or a multivitamin that has at least 400 micrograms of folic acid a day, advised Dr. Deborah Campbell, director of the division of neonatology at the Children's Hospital at Montefiore Medical Center in New York City.

But more evidence is needed to know for sure if doing so will help prevent language delays, she added.

"This is an interesting study showing an association with severe language delays, but I don't know that there's enough here to show causality," Campbell said.

More Information

Learn more about the importance of folic acid from U.S. Department of Health and Human Services Offic...n Women's Health.