The Effects of Socially-Patterned Exposures on Early Childhood Growth

Abstract

There is a growing body of research that suggests that risk factors in the prenatal period and early childhood are important to the development and prevention of overweight in childhood and its sequelae across the life course. The objective of this dissertation is to elucidate the relationships between socially-patterned maternal exposures and early childhood weight. The three studies draw on the Early Childhood Longitudinal Study-Birth Cohort, a nationally-representative sample of children born in the United States in 2001 and followed from birth through kindergarten. Chapter 1 examines the relationship between maternal pregnancy intention status and subsequent child’s weight at ages 9 months, 2 years, and 4 years using linear regression and multilevel models. Children from pregnancies reported by the mother as unwanted were more likely to have higher weight-for-length z-scores than children from pregnancies reported as intended only at age 9 months, and breastfeeding duration partially mediated the relationship. Chapter 2 examines whether timing of mother’s return to work after childbirth is associated with early childhood weight and height at ages 9 months, 2 years, and 4 years, and whether this association varies by household socioeconomic status and maternal race and ethnicity. Results from linear regression models suggest that mother’s earlier return to work is associated with lower height for children from lower socioeconomic status households compared to their peers from high socioeconomic status households. Chapter 3 investigates the associations between enactment of state-level breastfeeding promotion laws, specifically pertaining to breastfeeding in public, breastfeeding or pumping in the workplace, and breastfeeding mothers being exempt from jury duty, and child’s weight-for-length z-score at 9 months of age, and examines whether these relationships vary across mother’s racial and ethnic groups. Results from multilevel models examining each of the state-level breastfeeding laws were null. Using a nationally-representative longitudinal dataset, this dissertation contributes new scientific evidence and sheds light on potential mechanisms that can affect early childhood weight, which can help inform policies and programs aimed at reducing inequalities in early childhood health.