Body Mass Index Trajectories: The Effect of Fetal Size and Early Life Modifiable Factors

Background: This study examined the relationship between small for gestational age (SGA) status at birth, a measure of fetal growth restriction, and childhood body mass index trajectories (BMI) using data from the National Longitudinal Survey of Children and Youth. Analytic Method: Using latent growth curve modeling, the growth trajectories of a cohort of small and appropriate for gestational age singletons were modeled from 2-10 years (N=1,273 at baseline). Results: SGA status had no effect on the growth trajectories of children after adjusting for prenatal and early life sociodemographic and maternal variables, and also early life modifiable factors. Moreover, the modifiable factors (physical activity, sedentary screen time and sleep duration) had no effect on childhood BMI. Conclusion: The findings of this study do not lend support to the fetal origins hypothesis, which state that adaptations to adverse conditions in utero results in increased risk of disease in later life.