Maternal Diet Quality And Obesity In Pregnancy Jointly Influence Neonatal Adiposity

Objective A poor maternal diet in pregnancy may influence fetal growth and may compound the effect of maternal obesity on neonatal adiposity. In a cohort of 978 mother-offspring pairs we investigated maternal diet quality and it's interaction with maternal pre-pregnancy body mass index (BMI) on neonatal adiposity (percent fat mass, %FM). Methods Diet in pregnancy was assessed via repeated Automated Self-administered 24-hour dietary recalls, yielding Healthy Eating Index 2010 (HEI) scores (0-100) for each mother. HEI score was categorized into tertiles (<57, 57-65, >66), with low scores representing poor diet quality. Pre-pregnancy BMI was obtained from medical records or self-report. Neonatal %FM was assessed near birth using air displacement plethysmography. Using a multivariable model with neonatal %FM as the outcome, categorized HEI and BMI as predictors, and multiple covariates, we used F tests to examine components of the interaction between HEI and BMI. Results Total HEI score ranged from 38.0 to 88.7 (mean: 62.4, SD: 10.3). Means for %FM by BMI and HEI trended upward with worsening tertiles of HEI score and increasing categories of BMI (Figure 1). There was an interaction between the lowest HEI tertile and obese BMI (β =1.25, 95% CI: 0.01-2.50, p<0.05). Conclusions Pre-pregnancy obesity and poor diet synergistically increase neonatal adiposity. Dietary interventions targeted at women with obesity before pregnancy may reduce neonatal adiposity.