RT Journal Article SR Electronic T1 Aetiological factors in hypospadias. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 333 OP 337 DO 10.1136/jmg.23.4.333 VO 23 IS 4 A1 Calzolari, E A1 Contiero, M R A1 Roncarati, E A1 Mattiuz, P L A1 Volpato, S YR 1986 UL http://jmg.bmj.com/content/23/4/333.abstract AB Epidemiological and genetic variables in hypospadias were analysed during the years 1978 to 1983 in a case control study of congenital malformations in the Emilia Romagna region of northern Italy. During the observation period, in a sample of 41 078 male newborns, 168 had hypospadias giving a prevalence at birth of 4.1 in 1000 males. Hypospadias was divided into three types: type I or mild (75.0%); type II or moderate (21.4%); and type III or severe (3.6%). Coexisting malformations were found in 8.9% of cases. The heritability coefficient was 0.669. Maternal risk factors correlated with hypospadias were found to be early age at menarche, threatened abortion, and exposure to progestins. Low birth weight and shorter gestation were also correlated with hypospadias.