County-Level Environmental Quality and Risk of Hypospadias in Arkansas

Hypospadias is one of the most common genital defects in boys, affecting about 1 in 125 live-born boys. Several studies have examined the association between a single environmental exposure and risk of hypospadias, but few have examined the possible effects of multiple environmental exposures simultaneously. Thus, we aimed to address this gap by examining the association between cumulative maternal prenatal environmental exposures and hypospadias occurrence in offspring.

We conducted a retrospective cohort study using data from 2006 to 2010 Arkansas environmental quality index (EQI), its domains (air, water, land, sociodemographic, and built) and related county-level estimates, matched to data on infants diagnosed with hypospadias and identified from the Arkansas Reproductive Health Monitoring System born 2005-2012. We classified the EQI and its domains into quartiles. Crude and adjusted prevalence ratios (PR) and 95% CI were estimated with Poisson regression analyses with cluster-robust standard error to estimate the association between EQI and the prevalence of hypospadias.

There was no statistically significant association between boys born in areas with fair environmental quality compared to those born in areas with better environmental quality (adjusted PR = 1.01; 95% CI = 0.86, 1.18). For the air domain, we observed a higher prevalence of hypospadias among boys born to women living in areas with fair air quality compared to those living in areas with excellent air quality (adjusted PR = 1.18; 95% CI = 1.01, 1.39).

Our results suggest that there was no significant association between overall poor environmental quality index and the prevalence of hypospadias. However, poorer air quality was associated with a higher prevalence of hypospadias among offspring.