Women who take folic acid supplements during their first eight weeks of pregnancy significantly reduce their babies’ risk of having severe language delay when they are three years old, researchers from the Norwegian Institute of Public Health reported in JAMA (Journal of the American Medical Association). The authors say their findings may have major implications for understanding the biological processes that underlie disrupted neurodevelopment, as well as for the prevention of neurodevelopmental disorders.

The researchers wrote:

“Randomized controlled trials and other studies have demonstrated that periconceptional [the period from before conception to early pregnancy] folic acid supplements reduce the risk of neural tube defects. To our knowledge, none of the trials have followed up their sample to investigate whether these supplements have effects on neurodevelopment that are only manifest after birth.”

Christine Roth, M.Sc., Clin.Psy.D. and team set out to determine whether taking folic acid supplements during pregnancy might be linked to a lower risk of severe language delay in their offspring when they reached the age of 3 years.

Roth wrote:

“Unlike the United States, Norway does not fortify foods with folic acid, increasing the contrast in relative folate status between women who do and do not take folic acid supplements.”

They recruited pregnant mothers at the start of the study in 1999 and gathered data on children born before 2008 whose mothers had completed follow-up questionnaires up to June 2010. The researchers were especially interested in folic acid supplement intake 4 weeks before conception until 8 weeks into pregnancy.

Their main focus was the children’s language competency at 3 years of age. Those with only 1 word or unintelligible utterances were rated as having a severe language delay.

They gathered data on 19,956 boys and 18,998 girls. Below are some highlighted data from their findings:

  • 204 (0.5%) of them had severe language delay, 0.8% of the boys and 0.2% of the girls.
  • Of the 9,052 children whose mothers took no folic acid supplements during the period 4 weeks before conception until 8 weeks after conception, 0.9% had severe language delays.
  • Among the 2,480 mothers who took supplements but not folic acid, 0.9% of the offspring had severe language delays at the age of 3 years.
  • Among the 7,127 women who took folic acid only, 0.4% of the offspring had severe language delays at the age of 3 years.
  • Among the 19,005 women who took folic acid as well as other supplements, 0.4% of the offspring had severe language delays at the age of three years.

The authors wrote that according to their data, it is clear that during the period of 4 weeks before conception to 8 weeks after it, intake of folic acid is linked to a significant reduction in the risk of severe language delay in their offspring at the age of three years.

The researchers wrote:

“We found no association, however, between maternal use of folic acid supplements and significant delay in gross motor skills at age 3 years. The specificity provides some reassurance that there is not confounding by an unmeasured factor. Such a factor might be expected to relate to both language and motor delay.”

They concluded:

“If in future research this relationship were shown to be causal, it would have important implications for understanding the biological processes underlying disrupted neurodevelopment, for the prevention of neurodevelopmental disorders, and for policies of folic acid supplementation for women of reproductive age.”

Written by Christian Nordqvist