Prenatal Stress and Early Childhood Body Mass Index: A Path Analysis Approach.

OBJECTIVES Stress experienced by mothers during the prenatal period can have negative impacts on offspring development. Elevated BMI in childhood in response to early stress experience is a particularly critical outcome of interest since high BMI in childhood is associated with diabetes, heart disease and stroke in later life. The primary objective of this study was to analyze pathways between prenatal stress and early childhood BMI at 54-months of age and to begin to explore ethnic variations in these pathways. METHODS This study used the Growing Up in New Zealand (GUiNZ) dataset, which is a longitudinal, representative birth cohort study that began with recruiting pregnant women in 2009 and 2010 in Auckland, New Zealand. Path analysis modeling was used to explore risk and protective pathways between prenatal maternal stress and early childhood body mass index (BMI) at 54-months of age and differences by ethnicity (n = 5510). RESULTS Prenatal stress was positively associated with early childhood BMI at 54-months and maternal nutrition behaviors and length of exclusive breastfeeding mediated this direct relationship (χ2 (1) = 0.83, p = 0.36; AIC = 50,496). Mediation and moderation paths varied by ethnicity. CONCLUSIONS FOR PRACTICE These findings contribute to the understanding of the intergenerational transmission of stress with respect to early childhood obesity. Reducing early stress exposure and/or addressing mediating and moderating factors linking stress experience with obesity development may prove to be more effective than attempting to alter health behaviors and trajectories in adulthood.