Comparing the incidence of hypospadias across the United States: A contemporary analysis.

Introduction: Hypospadias is a common congenital malformation occurring in up to 80 in 10,00 live male births, with emerging evidence associating exogenous environmental exposures with increased disease incidence. Military personnel are at particularly higher risk for such exposures and indeed, the rate of hypospadias in infant males born to United States military servicewomen deployed during the Gulf War has been reported to be more than 5 times greater compared to undeployed female military personnel.

Objective: To characterize contemporary trends in hypospadias incidence in the general population as well as high risk groups such as males born from US servicewomen using the National Birth Defects Prevention Network.

Study design: We queried the National Birth Defects Prevention Network and the Office of Statewide Health Planning and Developing for rates of hypospadias in the general US population and each state as well as the Department of Defense. Hypospadias rates were compared between 2014 and 2018. Median household income by state was obtained from the 2018 United States Census Bureau Data to compare differences in hypospadias incidence by state and median household income from 2014 to 2018.

Results: The incidence of hypospadias in the United States was 71.6 per 10,000 male births between 2014 and 2018 (Table 1). In 2018, the states/entities with the highest incidence of hypospadias were the Department of Defense (113.19 per 10,000), Colorado (113.47 per 10,000), Tennessee (109.14 per 10,000), and Alabama (104.06 per 10,000). There was no significant association between hypospadias incidence and median state household income (p = 0.71).

Discussion: Our findings suggest that hypospadias incidence was significantly higher within the Department of Defense registry and in the states of Colorado, Tennessee, and Alabama compared to the national average. This identifies a regionalized incidence for hypospadias which is likely multifactorial and warrants further investigation.

Conclusions: The incidence of hypospadias in the United States was 71.6 per 10,000 male births in 2014-2018, with the highest rates reported in the Department of Defense, Colorado, Tennessee, and Alabama.