Birth Outcomes and Maternal Residential Proximity to Natural Gas Development in Rural Colorado

TLDR

Birth defects are a leading cause of neonatal mortality, and natural gas development emits potential teratogens that may increase risk. The study examined whether maternal proximity to natural gas wells is associated with adverse birth outcomes in a large rural Colorado cohort, highlighting the need for more precise exposure assessment. Exposure was estimated by inverse distance weighted well counts within 10 miles of maternal residence, and associations were assessed using logistic regression adjusted for maternal and infant covariates. Higher natural gas well density within 10 miles was associated with increased odds of congenital heart defects (OR 1.3) and possibly neural tube defects (OR 2.0), while exposure was linked to a small reduction in preterm birth and a slight increase in fetal growth, with no effect on oral clefts.

Abstract

Birth defects are a leading cause of neonatal mortality. Natural gas development (NGD) emits several potential teratogens, and U.S. production of natural gas is expanding.We examined associations between maternal residential proximity to NGD and birth outcomes in a retrospective cohort study of 124,842 births between 1996 and 2009 in rural Colorado.We calculated inverse distance weighted natural gas well counts within a 10-mile radius of maternal residence to estimate maternal exposure to NGD. Logistic regression, adjusted for maternal and infant covariates, was used to estimate associations with exposure tertiles for congenital heart defects (CHDs), neural tube defects (NTDs), oral clefts, preterm birth, and term low birth weight. The association with term birth weight was investigated using multiple linear regression.Prevalence of CHDs increased with exposure tertile, with an odds ratio (OR) of 1.3 for the highest tertile (95% CI: 1.2, 1.5); NTD prevalence was associated with the highest tertile of exposure (OR = 2.0; 95% CI: 1.0, 3.9, based on 59 cases), compared with the absence of any gas wells within a 10-mile radius. Exposure was negatively associated with preterm birth and positively associated with fetal growth, although the magnitude of association was small. No association was found between exposure and oral clefts.In this large cohort, we observed an association between density and proximity of natural gas wells within a 10-mile radius of maternal residence and prevalence of CHDs and possibly NTDs. Greater specificity in exposure estimates is needed to further explore these associations.