Neonatal Adiposity and Childhood Obesity.

Objectives: To explore the longitudinal association of neonatal adiposity (fat mass percentage) with BMI trajectories and childhood overweight and obesity from ages 2 to 6 years.

Methods: We studied 979 children from the Healthy Start cohort. Air displacement plethysmography was used to estimate fat mass percentage. Child weight and recumbent length or standing height were abstracted from medical records. Overweight and obesity were defined as BMI levels ≥85th percentile for age and sex. Mixed-effects models were used to examine the association between neonatal fat mass percentage and BMI trajectories from age 2 to 6 years. We tested for effect modification by sex, race and/or ethnicity, and breastfeeding duration. We estimated the proportion of children classified as overweight or obese at specific levels of neonatal fat mass percentage (mean ± SD).

Results: The mean neonatal adiposity level was 9.1% ± 4.0%. Child BMI levels differed by neonatal adiposity. Each SD increase in neonatal adiposity resulted in a 0.12 higher overall BMI level between ages 2 to 6 years (95% confidence interval: 0.03 to 0.20; < .01), and this association was not modified by offspring sex, race and/or ethnicity, or breastfeeding duration. Increasing neonatal adiposity was associated with an increasing proportion of childhood overweight and obesity by age 5 years ( = .02).

Conclusions: We provide novel evidence that higher neonatal adiposity is significantly associated with higher overall BMI levels and an increased likelihood of overweight or obesity from ages 2 to 6 years. Because various prenatal exposures may specifically influence offspring fat accretion, neonatal adiposity may be a useful surrogate end point for prenatal interventions aimed at reducing future childhood overweight and obesity.