Epidemiology of hypospadias in China: A nationwide surveillance-based study, 2010-2020.

Abstract

Background: The prevalence of hypospadias varied internationally. However, epidemiological data on hypospadias in contemporary China remain limited.

Objectives: We aim to examine the epidemiological characteristics of hypospadias in Chinese population.

Materials and methods: We performed a prevalence analysis using data from the Chinese Birth Defects Monitoring Network from 2010 to 2020. We analyzed the prevalence of overall, isolated, and associated hypospadias by birth year, maternal age, maternal residence, and geographic region. We used Poisson regression with adjusted prevalence rate ratios for assessing the impact of demographic characteristics and Joinpoint regression for analyzing temporal trends.

Results: A total of 11,782 hypospadias cases were identified among 11,575,036 male births with a prevalence of 10.18 per 10,000 male births. Of these, 9700 (82.3%) were isolated and 2082 (17.7%) were associated hypospadias. Of these cases, 639 (5.4%) were classified as anterior hypospadias, 1052 (8.9%) as middle hypospadias, 413 (3.5%) as proximal hypospadias, and 9678 (82.1%) as unspecified hypospadias, based on their severity. The prevalence of overall, isolated, and associated hypospadias increased significantly over the study period. Prevalence also varied significantly by maternal residence, maternal age, and geographical region. Infants with associated hypospadias experienced a significant higher risk of perinatal death. The most frequent associated anomalies involved the cardiovascular, genitourinary, and musculoskeletal systems.

Discussion and conclusion: This study provides contemporary national data on the epidemiology of hypospadias in China. The observed increasing prevalence and variations by severity underscore the need for further etiological, epidemiological, and clinical research.