Impact of Maternal Characteristics and Fetal Growth on Early Child Growth Trajectories

Background: This study aimed to determine the impacts of maternal characteristics and fetal growth status at birth on growth trajectories in childhood using lifecourse approaches with nationally representative longitudinal data.

Methods: Data were from the Early Childhood Longitudinal Study, the 2001 Birth Cohort (n=6,650). Polynomial growth curve modeling and piecewise linear modeling were used to capture the impacts of pre-, peri-, and post-natal risk factors on the body mass index (BMI) or BMI percentile trajectories after adjusting for other co-variates. Generalized estimating equations and alternative modeling strategies were fitted to validate the robustness of the results.

Results: Adiposity rebound was found at around 24 months (i.e.; the change of BMI percentile slope at 24 months: b=0.41, s.e.=0.11, p<0.01). Rapid catch-up growth among infants born early (gestational age: b=-0.03, s.e.=0.01, p<0.01) was found during 0 and 24 months. We also found positive gradients between maternal BMI before pregnancy as well as maternal weight gain during pregnancy and child BMI percentile trajectories. No associations were found between household SES or poverty status and BMI percentile trajectories.

Conclusions:  This study provided a rigorous evaluation of growth trajectories during early childhood as a function of maternal characteristics and fetal growth status. Our results support the conclusion that maternal pre-pregnancy BMI, weight gain during pregnancy and fetal growth status at birth are important determinants of the risk of obesity during early childhood. Therefore, interventions to curb childhood obesity may need to address upstream determinants before and during pregnancy.