Maternal Dietary Anthocyanidin, Dietary Inflammatory Potential, and Risk of Small-for-Gestational-Age in China

<b>Background:</b> The interaction between anthocyanidin intake and dietary inflammatory potential might influence small-for-gestational-age (SGA), but the available evidence has been limited. This study aims to examine the associations of anthocyanidin with SGA and whether these associations change with dietary inflammatory potential. <b>Methods:</b> Data were derived from 2244 pregnant women enrolled in a community-based, randomized controlled trial between 2015 and 2019 in China. Anthocyanidin intake was calculated with the use of validated food-frequency questionnaires. The energy-adjusted dietary inflammatory index (EDII) was determined by aggregating data from 33 food parameters. Infant birth outcome measurements were obtained from hospital records. Associations were assessed by generalized estimating equations with adjustment for confounding factors. <b>Results:</b> During 39.7 gestational weeks of follow-up, 234 SGA cases occurred. The median intake of anthocyanidin was 28.7 mg/d. Higher consumption of total anthocyanidins (OR: 0.96, 95% CI: 0.95 to 0.97), cyanidin (OR: 0.96, 95% CI: 0.95 to 0.97), and peonidin (OR: 0.96, 95% CI: 0.96 to 0.97) subclasses was associated with a reduced risk of SGA. EDII was associated with an increased risk of SGA (OR: 1.08, 95% CI: 1.03 to 1.12). In addition, we observed that higher anthocyanidin intake was inversely associated with EDII (β: -0.40, 95% CI: -0.46 to -0.34). The inverse anthocyanidin-SGA association was mostly greater among women in the highest tertile of EDII (OR: 0.67, 95% CI: 0.65 to 0.68) compared with the lowest tertile. <b>Conclusions:</b> Higher anthocyanidin intake was inversely associated with SGA, especially among women with higher EDII scores.