From nutrient intake to socioeconomic factors: what shapes diet quality in pregnancy?

Abstract Background Optimising maternal diet quality is among the most promising targets for public health interventions to improve the health of current and future generations. The aim of this study was to assess the construct validity of the Canadian Pregnancy Diet Quality Index (DQI-P C ) in Romania by: (i) examining its associations with nutrient adequacy, including nutrients not included in the index (non-constituent nutrients), and (ii) evaluating whether DQI-P C scores differ across sociodemographic characteristics known to influence diet quality. Methods A cross-sectional study ( n = 647) was conducted to determine DQI-P C and nutrient intake using a previously validated food-frequency questionnaire. DQI-P C scores were assessed across categories of education, income, age, and parity. Furthermore, the relationship between DQI-P C and macro- and micronutrients was examined using correlation coefficients. Results Mean DQI-PC score was 42.1 out of 70. Inadequate intake (< 90%RDA, Recommended Dietary Allowance) of micronutrients, particularly important during pregnancy, such as vitamin D, iron, and folate, was observed, and all participants fell below recommendations. DQI-PC was strongly associated with higher nutrient adequacy across almost all micronutrients. A higher DQI-PC score was associated with significantly higher %RDA for nearly all vitamins (B1, B2, B6, B12, A, C, D and E; all p < 0.001). Spearman correlation analysis confirmed significant associations between DQI-PC and all dietary components (all p < 0.001). Strong positive correlations were observed for folate (rho = 0.65) and iron (rho = 0.53), while total fat intake showed a strong negative correlation (rho = − 0.55). Participants with higher income had significantly higher DQI-PC scores than those with lower income (42.66 vs 40.92, p = 0.007). Higher income was also linked to better adequacy for grain and iron (both p = 0.007 or less), while total fat intake (% of energy) and fruit consumption were notably higher in the lower income group (both p < 0.001). Conclusions Despite the well-documented importance of nutrition during pregnancy, significant inadequacies persist in practice. The DQI-PC, originally developed in Canada, is a valuable tool for predicting intake of all major nutrients during pregnancy across multiple countries.