Hypospadias results in various degrees of deficiency of the urethra, corpus spongiosum, and corpora cavernosa. The fibrous tissue that causes ventral curvature replaces Buck fascia and dartos fascia. The skin on the ventral surface may be thin; the prepuce is deficient ventrally and forms a dorsal hood over the glans.
As a rule, the location of the meatus does not cause significant obstructive urinary symptoms, although ventral deflection of the stream of urine commonly occurs. When the meatus is more proximal, the stream flows straight downward or backward, requiring the patients to urinate ad modum feminarum. Uncorrected, the curvature of the penis is likely to cause painful erections and result in severe psychologic consequences.
The incidence of hypospadias is about 1 in every 300 male children. If minor degrees of hypospadias are included, this incidence may be as high as 1 in 125 male births. If 1 848 500 male births occur in the United States, we should see 6200 hypospadias cases each year.
The risk of occurrence in an infant is 8% if his father has hypospadias and 14% if a sibling has the condition; if two members of the same family have hypospadias, the risk is about 21%.
The cause of hypospadias is still unknown.