An epidemiologic study of penoscrotal transposition by maternal characteristics using data from the Texas birth...

Penoscrotal transposition (PST) is an uncommon urogenital malformation in which the penis is mal-positioned to be inferior to the scrotum. The purpose of this study was to explore PST risk by maternal characteristics and to describe co-occurring congenital abnormalities in the Texas Birth Defects Registry (TBDR).

We conducted a population-based descriptive study examining occurrence of PST in the TBDR between 1999 and 2019. The primary outcome variable was PST diagnosis during infancy. Descriptive variables included maternal age, education, and race/ethnicity. Prevalence ratios (PRs) were calculated within each maternal variable category using Poisson regression. Counts and percentages of cases with select co-occurring congenital abnormalities were also calculated.

Overall, 251 infants had PST, providing a prevalence of 0.61/10,000 live male births (95% CI: 0.53-0.68). PST prevalence was significantly lower among infants of mothers who had lower educational attainment (high school), who were younger (<25 vs. 25-34), and who were Hispanic (vs. non-Hispanic White) and was significantly higher among older mothers (35+ vs. 25-39). Hypospadias was the most common co-occurring genitourinary anomaly, affecting close to 70% of cases.

To our knowledge, this is the first investigation exploring the prevalence of PST in a population-based birth defects registry. Our findings help to understand the risk for PST among select maternal demographic characteristics and may assist in generating hypotheses about the underlying etiology of this condition for future work.