The ecology of birth defects: socio-economic and environmental determinants of gastroschisis in North Carolina Public Deposited

Downloadable Content

Download PDF
Last Modified
  • March 22, 2019
  • Root, Elisabeth Dowling
    • Affiliation: College of Arts and Sciences, Department of Geography
  • Gastroschisis is a serious birth defect that has increased in prevalence in North Carolina over the past decade. The causes of the defect, and the reasons for this increase, are largely unknown. This study uses the disease ecology framework and spatial methodologies - spatial statistics, Geographic Information Systems, and hydrological modeling - to explore the geographic distribution of gastroschisis in North Carolina and suggest possible socioeconomic and environmental factors that may contribute to the disease. Specific questions addressed in this study include: 1) Do significant geographic clusters of gastroschisis exist in North Carolina? 2) Do clusters suggest the presence of point-source environmental pollutants? 3) What area-level socioeconomic characteristics are related to gastroschisis outcomes? 4) What can this tell us about possible causes of the disease? Using data from a population-based birth defects registry, this study uses Kulldorff's spatial scan statistic to identify the location and extent of clusters of gastroschisis births in North Carolina between 1999 and 2004. Spatial clusters are controlled for four major risk factors (maternal age, race, prior births and Medicaid status) to ensure that the clusters are not an artifact of the population composition of the State. The relationship between neighborhood socioeconomic characteristics (e.g., race, poverty, education and unemployment) and gastroschisis outcomes are examined using logistic regression models, which combine individual-level and neighborhood-level variables. Finally, simple hydrological models are used to determine if exposure to upstream textile mill effluent increases the risk for a gastroschisis affected pregnancy. Results indicate the presence of a localized cluster of gastroschisis in the rural southern Piedmont of North Carolina. In addition, both individual-level (Medicaid status) and neighborhood-level (poverty and unemployment) socioeconomic factors appear to contribute to the risk of a gastroschisis affected pregnancy, suggesting that neighborhood-level socioeconomic factors exert an independent causal effect on gastroschisis. Despite the localized nature of the cluster, which often suggests the presence of an environmental contaminant, there is no evidence to support this hypothesis. These results may help understanding the myriad social, economic and environmental factors that combine and interact to influence gastroschisis outcomes.
Date of publication
Resource type
Rights statement
  • In Copyright
  • Emch, Michael
Degree granting institution
  • University of North Carolina at Chapel Hill
  • Open access

This work has no parents.