AN EPIDEMIOLOGICAL STUDY OF HYPOSPADIAS IN SWEDEN

Abstract

ABSTRACTThe prevalence at birth of hypospadias started to increase in the beginning of the 1970s, as judged from the registration in the Swedish Register of Congenital Malformations. Further studies supported the notion that the increase was real and not due to registration artifacts. A study of the geographical distribution showed an uneven distribution in the country. Three case‐control studies with different design were performed in order to find an aeti‐ological factor which could explain the observations. None was found. No support could be obtained for a role of gestagens in the aetiology of hypospadias. A hypothesis is presented based on an observation of a possibly increased infertility—possibly male—in the couples who had a boy with hypospadias. The possible implications of this finding for aetiological studies are discussed in the light of current literature. Based on a possible male subfertility, a hypothesis is presented which could explain the noticed increase in prevalence of hypospadias in the early seventies.The hypospadiac infants were analysed from various points of view. There were signs of a generally disturbed fetal development. Thus a shorter than normal gestational age with a component of growth failure was found. There was a statistically significant association, not only with other genital malformations such as retentio testis, but also with congenital heart disease, cleft lip/palate, anal atresia, and neural tube defects. The analysis indicates that this association was not random, but possibly indicates common teratogenic pathways.