Secular trends of hypospadias prevalence and factors associated with it in southeast China during 1993-2005.

BACKGROUND

The aim of this study is to describe the prevalence of hypospadias and its time trends during 1993-2005 in southeast China, and to explore the potential risk factors.

METHODS

The study population included all male live and still births (at least 20 weeks of gestation) in 11 cities and counties in Jiangsu and Zhejiang Provinces in Southeast China born during January 1, 1993, through December 31, 2005.

RESULTS

Overall prevalence of hypospadias was 5.8 per 10,000 male births and presented an increasing trend during 1993-2005 (with chi(for trend) (2) of 3.94, p = 0.047). Prevalence of coronal hypospadias and those with unknown sites increased from 1.7 and 0.3 per 10,000 male births in 1993 to 3.6 and 1.4 per 10,000 male births in 2005, respectively (with chi(for trend) (2) of 7.29 and 9.05, p = 0.007 and p = 0.002, respectively), but prevalence of perineal hypospadias decreased (with chi(for trend) (2) of 7.13, p = 0.008). Maternal fever during first trimester, birth of twins or more children, and year of birth were independent risk factors for hypospadias, with odds ratios of 4.14 (95% CI, 1.32-12.83), 3.37 (95% CI, 1.73-6.58), and 1.04 (95% CI, 1.00-1.08), respectively, after adjusting for confounding factors with multivariable logistic regression analysis.

CONCLUSIONS

Prevalence of hypospadias increased during 1993-2005 in the two provinces in southeast China. Maternal fever in the first trimester and birth of twins or more children are associated with the risk for hypospadias.