13 Does Folic Acid Intake in Pregnancy Increase Risk of Wheeze at 18 Months? Evidence From the Danish National Birth Cohort.

Abstract

Background: Recent evidence suggests that maternal supplementation of folic acid during pregnancy may play a role in the development of wheezing and asthma among offspring, potentially through epigenetic mechanisms. Objective: We examined associations of maternal prenatal intake of folic acid supplements and dietary folate with wheeze and recurrent wheeze among offspring at age 18 months in the Danish National Birth Cohort. Methods: We estimated maternal intake of folic acid via supplements and dietary folate (n=54,440) using a validated FFQ completed in mid-pregnancy. We defined wheeze as a positive maternal report of child wheezing on either the 6 or 18 month interview, and recurrent wheeze as ≥3 wheeze episodes with the first occurring before 15 months of life. We conducted logistic regression analyses controlling for potential confounders, and report here estimates for the highest vs. lowest quartiles. Results: Of the 54,440 children, 14.2% (n=7,703) had wheezed and 3.0% (n=1,619) had recurrent wheezing by 18 months. Maternal intake of folic acid supplements was not associated with child wheezing (OR: 1.06, 95% CI: 0.93, 1.21) or recurrent wheezing. (OR: 1.13, 95% CI: 0.88, 1.46) Similarly, dietary folate was not associated with wheezing (OR: 0.95, 95% CI: 0.87, 1.04) or with recurrent wheeze (OR: 0.90; 95% CI: 0.74, 1.08). Conclusions: We found no association of maternal mid-pregnancy intake of folic acid supplements or dietary folate with wheezing in early childhood. Maternal folic acid status at conception may be more important in influencing child epigenetic imprinting and subsequent outcomes.