557 - Association between maternal serum folic acid levels and onset of Kawasaki disease in offspring during infancy: The Japan Environment and Children’s Study

Poster Number: 557
Publication Number: 557.317

Background: Kawasaki disease (KD) is an acute systemic vasculitis that primarily affects infants and young children. No reproducible risk factors have yet been identified. We previously reported a possible association between maternal folic acid supplementation and KD.

Objective: In this study, we aimed to further investigate the relationship among maternal serum folic acid levels, maternal folic acid supplementation, and onset of KD during infancy in offspring.

Design/Methods: We used data from the Japan Environment and Children’s Study, a nationwide birth cohort, which has followed approximately 90,000 children since 2011. We obtained information on exposures and outcomes, including onset of KD, from the first trimester to 12 months of age from the dataset released in October 2019. The primary outcome was the onset of KD in offspring up to age 12 months of age. We selected the following three exposures, maternal serum folic acid levels (≥10 ng/mL classified as exposed) in the second/third trimester and the frequency of maternal folic acid supplementation in the first trimester and during the second/third trimester of pregnancy (once a week or more classified as exposed). Primary exposure is maternal serum folic acid levels. In addition, we created three models to analyze each of the three exposures. We used a basic model including 35 prenatal variables (Model 1) and two models for sensitivity analyses. The sensitivity analysis models include i) variables for previously reported risk factors of KD (Model 2) and ii) variables that may affect folic acid intake behavior (Model 3). Odds ratios (ORs) for each exposure were estimated and propensity score-adjusted logistic regression was performed based on the each three models.

Results: The study population comprised 87,702 children who were followed for 12 months. Of these, 336 children developed KD. Mothers who took folic acid supplements tended to have higher serum folic acid levels. (Figure1) Higher maternal serum folic acid levels were significantly associated with a lower risk of KD (OR, 0.68; 95% CI, 0.50–0.92). (Table1) Additionally, folic acid supplementation during the first trimester was associated with a lower risk of KD (OR, 0.83; 95% CI, 0.66–1.04), and supplementation during the second/third trimester was significantly associated with a lower risk of KD (OR, 0.73; 95% CI, 0.57–0.94). (Table2)

Conclusion(s): In this cohort study, higher maternal serum folic acid levels and maternal folic acid supplementation during the second/third trimesters may reduce the risk of KD in offspring during infancy.