Prenatal folic acid and asthma

Folic acid supplementation during pregnancy helps prevent neural tube defects such as spina bifida. An animal model suggests that a prenatal diet with high levels of folic acid may be a risk factor for respiratory diseases, but epidemiologic studies have had conflicting results.

In a study published in the journal Epidemiology, Kecia N. Carroll, M.D., MPH, and colleagues report that the timing of folic acid-containing prescription filling during pregnancy was associated with childhood asthma.

The researchers conducted a retrospective cohort study of 104,428 children born between 1996 and 2005 and their mothers enrolled in Tennessee Medicaid. They found that children born to women with folic acid prescription exposures in the first trimester only or first trimester and beyond were 20 percent more likely to have asthma at ages 4.5 to 6, compared to children with no exposure. There was no association for children born to women exposed after the first trimester.

The findings contribute to ongoing efforts to understand the role of prenatal nutritional supplements in the development of childhood respiratory diseases.

This research was supported by National Institutes of Health grants HL109977 and RR024975.

– by Leigh MacMillan