Trends in the prevalence of recorded isolated hypospadias in Hungarian newborn infants during the last 50 years - a population-based study.

Previously an increasing birth prevalence of hypospadias was recorded in some countries, including in Hungary. However, a Hungarian clinical-epidemiological study estimated the so-called true birth prevalence of hypospadias (2.25+0.30 per 1000) based on the physical examination of newborns with well-defined diagnostic criteria. Thus the aim of this study was the critical analysis of the recorded annual birth prevalences of cases with isolated hypospadias (IHS) in the Hungarian Congenital Abnormality Registry during the last 50 years compared to the true birth prevalence of IHS. There was increasing trend of annual recorded prevalence of IHS with a further increase between 2005 and 2011 with the maximum of 3.42 per 1000 in 2011. However, this increase can be explained by the more complete reporting of IHS and a larger proportion of mild coronal subgroup. In conclusion, birth defect-registries are not appropriate for the estimation of true birth prevalence of IHS.