Adverse birth outcomes and childhood overweight at age of 3–8 years in a prospective cohort study in Tianjin, China

Abstract

Objectives To explore associations between adverse birth outcomes and childhood overweight at 3–8 years of age. Design A prospective cohort study. Setting Six central urban districts of Tianjin, China. Participants 1681 woman–child pairs. Methods 1681 woman–child pairs were followed up for 8 years in Tianjin, China. Demographic and clinical information including birth outcomes was collected longitudinally, commencing from first antenatal care visit till postpartum period. Offspring height and weight were measured at 3–8 years of age. High and low weight/ length ratios (WLR) at birth were, respectively, defined as ≥90th and ≤10th gestational week and sex-specific percentiles. Overweight for children at 3–5 and 6–8 years of age were, respectively, defined as body mass index (BMI)-for-age and -sex above the 2 z-score and 1 z-score curves of the WHO’s child growth standards. Binary logistic regression analysis was used to obtain ORs and 95% CI with a stepwise backward selection method to select independent predictors. Primary outcomes measures Childhood overweight. Results Of 1681 children, 10.7% (n=179) and 27.8% (n=468) developed overweight at 3–5 and 6–8 years of age, respectively. Large for gestational age (LGA) was associated with increased risk of overweight at 3–5 years of age (aOR: 1.86, 95% CI: 1.27 to 2.72) while high WLR at birth was associated with increased risk of overweight at 6–8 years of age (1.82, 1.41 to 2.34). Low WLR at birth was associated with decreased risk of overweight at 6–8 years of age (0.52, 0.30 to 0.90). Conclusions LGA and high WLR at birth predicted childhood overweight at 3–5 and 6–8 years of age, respectively. Low WLR at birth was associated with decreased risk of childhood overweight at 6–8 years of age.