Racial or Ethnic and Socioeconomic Inequalities in Adherence to National Dietary Guidance in a Large Cohort of US Pregnant Women.

Background: The significance of periconceptional nutrition for optimizing offspring and maternal health and reducing social inequalities warrants greater understanding of diet quality among US women.

Objective: Our objective was to evaluate racial or ethnic and education inequalities in periconceptional diet quality and sources of energy and micronutrients.

Design: Cross-sectional analysis of data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort.

Participants And Setting: Nulliparous women (N=7,511) were enrolled across eight US medical centers from 2010 to 2013.

Main Outcome Measures: A semiquantitative food frequency questionnaire assessing usual dietary intake during the 3 months around conception was self-administered during the first trimester. Diet quality, measured using the Healthy Eating Index-2010 (HEI-2010), and sources of energy and micronutrients were the outcomes.

Statistical Analyses: Differences in diet quality were tested across maternal racial or ethnic and education groups using F tests associated with analysis of variance and χ tests.

Results: HEI-2010 score increased with higher education, but the increase among non-Hispanic black women was smaller than among non-Hispanic whites and Hispanics (interaction P value <0.0001). For all groups, average scores for HEI-2010 components were below recommendations. Top sources of energy were sugar-sweetened beverages, pasta dishes, and grain desserts, but sources varied by race or ethnicity and education. Approximately 34% of energy consumed was from empty calories (the sum of energy from added sugars, solid fats, and alcohol beyond moderate levels). The primary sources of iron, folate, and vitamin C were juices and enriched breads.

Conclusions: Diet quality is suboptimal around conception, particularly among women who are non-Hispanic black, Hispanic, or who had less than a college degree. Diet quality could be improved by substituting intakes of refined grains and foods empty in calories with vegetables, peas and beans (legumes), seafood, and whole grains.