Pregravid body mass index is negatively associated with diet quality during pregnancy

Objective: To investigate the association between pregravid weight status and diet quality. Design: Institute of Medicine body mass index (BMI) cut-off points of < 19.8 kg m(-2) for underweight, 19.8-26.0 kg m(-2) for normal weight, >26.0-29.0 kg m(-2) for overweight and >29kg m(-2) for obese were used to categorise women's weight status. Dietary information was obtained by self-report at 26-28 weeks' gestation using a modified Block food-frequency questionnaire. The Diet Quality Index for Pregnancy (DQI-P) included: servings of grains, vegetables and fruits, folate, iron and calcium intake, percentage calories from fat, and meal pattern score. Multinomial logistic regression models were used to estimate the association between weight status and tertiles of DQI-P controlling for potential individual confounders. Setting: A clinical-based population recruited through four prenatal clinics in central North Carolina. Subjects: A total of 2394 women from the Pregnancy, Infection and Nutrition study were included in this analysis. Results: Evidence of a dose-response relationship was found between BMI and inadequate servings of grains and vegetables, and iron and folate intake. Pregravid obesity was associated with 76% increased odds of falling into the lowest diet quality tertile compared with underweight women after controlling for potential confounders. Conclusion: A modest association was found between pregravid weight status and diet quality. if corroborated, these findings suggest that overweight pregnant women should be targeted for nutrition counselling interventions aimed to improve diet quality.