RESUMO
Hypospadius is a defect of the urethra and penis in the male. In this research the incidence of the male hypospadius induced by estrogen [estradiol] administration was investigated during embryonic development. Three groups of pregnant rats were exposed to 0.15mg/kg estradiol valerate via a single intramuscular injection on one of the following gestational days: 12, 14 or 16 and named as experimental groups 1,2 and 3 respectively. All the pregnant rats were sacrificed on the last day of pregnancy [day 20]. The fetuses collected and counted and the external genitalas examined for detection of hypospadius as well as other malformations. The data showed that in addition to the significant reduction in the size of the litters in experimental groups, the incidence of the male hypospadius is high, especially in the group 1. Furthermore, most of the fetuses had severe malformations including anencephaly, exencephaly, agnatha, syndactyly and tetradactyly