Proinflammatory Diets during Pregnancy and Neonatal Adiposity in the Healthy Start Study.

OBJECTIVE: To evaluate the association between dietary inflammatory index (DII) scores during pregnancy and neonatal adiposity. STUDY DESIGN: The analysis included 1078 mother-neonate pairs in Healthy Start, a prospective prebirth cohort. Diet was assessed using repeated 24-hour dietary recalls. DII scores were obtained by summing nutrient intakes, which were standardized to global means and multiplied by inflammatory effect scores. Air displacement plethysmography measured fat mass and fat-free mass within 72 hours of birth. Linear and logistic models evaluated the associations of DII scores with birth weight, fat mass, fat-free mass, and percent fat mass, and with categorical outcomes of small- and large-for-gestational age. We tested for interactions with prepregnancy BMI and gestational weight gain. RESULTS: The interaction between prepregnancy BMI and DII was statistically significant for birth weight, neonatal fat mass, and neonatal percent fat mass. Among neonates born to obese women, each 1-unit increase in DII was associated with increased birth weight (53 g; 95% CI, 20, 87), fat mass (20 g; 95% CI, 7-33), and percent fat mass (0.5%; 95% CI, 0.2-0.8). No interaction was detected for small- and large-for-gestational age. Each 1-unit increase in DII score was associated a 40% increase in odds of a large-for-gestational age neonate (1.4; 95% CI, 1.0-2.0; P = .04), but not a small-for-gestational age neonate (1.0; 95% CI, 0.8-1.2; P = .80). There was no evidence of an interaction with gestational weight gain. CONCLUSIONS: Our findings support the hypothesis that an increased inflammatory milieu during pregnancy may be a risk factor for neonatal adiposity. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02273297.