Early initiation of folic acid or prenatal vitamin supplementation appears to offer a protective effect with respect to the prevention of wheeze in the offspring of mothers with a history of atopy (eg, hay fever, eczema, or asthma). A population-based study, published in the Maternal and Child Health Journal, sought to investigate the effect of folic acid use during pregnancy on adverse early childhood respiratory outcomes.
Data on self-reported folic acid or prenatal vitamin supplement use during pregnancy were collected 3 to 6 months’ postpartum from mothers in Los Angeles, California, who had given birth in 2003. Initiation of supplementation was based on which supplement — folic acid or prenatal vitamins — was started first by the woman. In a 2006 follow-up survey, approximately 50% of these women were contacted to gather information on their child’s respiratory health, including any diagnoses and symptoms, at approximately 3.5 years of age.
The results demonstrated that the timing of folic acid supplement initiation in pregnant women was not associated with the development of wheeze or lower respiratory tract infection in their offspring, even after preterm births and censoring at follow-up were taken into account. Children born to mothers with a history of atopy and who commenced folic acid supplementation in late pregnancy compared with first trimester initiators, however, had an increased risk for wheeze in the first 3 years of life (odds ratio, [OR], 1.67; 95% CI, 1.12-2.49) and an increased risk for wheeze in the past year (OR, 1.88; 95% CI, 1.05-3.34). A similar association was not observed in the children of mothers who did not have atopy.
The investigators concluded that early initiation of folic acid or prenatal vitamin supplementation by atopic women may help to prevent the development of wheeze in their offspring. Additional research is warranted, both on the maternal history of atopy as a potential modifier of the relationship between folic acid use and adverse early childhood respiratory outcomes and on the biologic mechanisms that may underlie this association.
Alfonso VH, Bandoli G, von Ehrenstein O, Ritz B. Early folic acid supplement initiation and risk of adverse early childhood respiratory health: a population-based study [published online September 8, 2017]. Matern Child Health J. doi:10.1007/s10995-017-2360-6