No link found between folic acid in pregnancy and childhood asthma

Contrary to earlier reports of a possible connection between folic acid and atopic disease, a Dutch study suggests that folic acid supplementation during pregnancy doesn’t increase the risk of asthma in the baby.

Researchers at Maastricht University, The Netherlands, identified folic acid supplementation among 2,834 pregnant women, then followed their children’s health using questionnaires and laboratory tests. They collected data on eczema and wheezing by questionnaires at 3, 7, 12, and 24 months, 4 to 5 years of age, and 6 to 7 years after delivery; assessed atopic dermatitis and total and specific immunoglobulin E levels at 2 years; and tested lung function and assessed for asthma at 6 to 7 years of age. Nearly 7% of the children developed asthma, regardless of whether their mothers had taken folic acid; children in both groups were similar in measurements of lung function and the number of allergic reactions.

“Our results do not confirm any meaningful association between folic acid supplement use during pregnancy and atopic diseases in the offspring,” the authors write. “Higher ICF [intracellular folic acid] levels in late pregnancy tended, at most, toward a small decreased risk for developing asthma.

Further, ”maternal ICF level in late pregnancy was inversely associated with asthma risk at age 6 to 7 years in a dose-dependent manner,” according to study authors.

Because ICF levels were measured in blood samples taken at about 35 weeks' gestation, the researchers caution that conclusions can’t be drawn about possible connections between ICF levels in early pregnancy and atopic disease in childhood. They note that more research is warranted on folic acid and ICF levels during pregnancy.

The study was published online June 20 in Pediatrics.