Maternal exposure to nitrate in drinking water and risk of cyanotic congenital heart defects

Background The rate of cyanotic congenital heart defects (CCHD), a group of major birth defects, has increased 88% from 2016 to 2023 in Utah. However, few studies have identified risk factors for this increasing trend. Therefore, this study assessed the association of drinking water contaminants with CCHD in Utah. Methods This study uses an ecological design to analyze the association between CCHD and drinking water contaminants in Utah. Birth data were collected from the Centers for Disease Control and Prevention National Center for Health Statistics birth database, and drinking water contaminant data were collected from the Environmental Protection Agency and United States Geological Survey Water Quality database. Multivariable logistic regression analyses were used to identify associations between drinking water contaminants and CCHD. Results Nitrate concentration in drinking water was positively and significantly associated with CCHD in Utah (OR: 3.41, 95% CI: 2.22–5.24, p -value <0.001). Furthermore, fertilizer expenditure and nitrate concentration showed similar increasing trends, suggesting fertilizers may be correlated with nitrate contamination in drinking water. Conclusion These findings suggest the CCHD increasing trend in Utah may be correlated with nitrate concentration in drinking water, and nitrate in drinking water may be correlated with fertilizers. Thus, decreasing the use of nitrate fertilizers may decrease the nitrate concentration in drinking water and the risk of CCHD in Utah.