Congenital diaphragmatic hernia and maternal dietary nutrient pathways and diet quality.

INTRODUCTION We examined the association of congenital diaphragmatic hernia (CDH) with maternal dietary intake, using semi-Bayes hierarchical models and principal components analysis to consider intake of nutrients that contribute to one-carbon metabolism and oxidative stress pathways, and a diet quality index. METHODS We included data on 825 cases and 11,108 nonmalformed controls born from 1997-2011 whose mother participated in the National Birth Defects Prevention Study (NBDPS), a multisite, population-based case-control study. Exposure data were from maternal telephone interviews, which included a food frequency questionnaire. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were generated from logistic regression models that included nutritional factors as continuous variables and were adjusted for maternal energy intake, race-ethnicity, parity, and vitamin supplement intake. RESULTS In the semi-Bayes hierarchical model that included all nutrients and confounders, riboflavin was the only nutrient for which the 95% CI excluded 1.0; the aOR for a 1 SD increase was 0.83. The aORs were 0.79 (95% CI 0.69-0.91) for the one-carbon metabolism pathway score, 0.90 (95% CI 0.80-1.01) for oxidative stress, and 0.85 (95% CI 0.77-0.93) for diet quality (the aORs correspond to a 1 SD increase). CONCLUSIONS The findings from this study provide some support for the hypothesis that better prepregnancy nutrition is associated with reduced risk for CDH. These results provide etiologic clues but should be interpreted with caution given the novelty of the investigation.