Definition and incidence
Hypospadias is a congenital abnormality in which the opening of the urethra is situated anywhere on the underside of the penis, instead of at its tip. There is an associated foreskin abnormality.
This is a common birth defect in males, found in 3-7 in 1,000 live births, though the prevalence varies widely in different countries.
Causes and associated factors
Most cases are sporadic, with only about 7 percent having a family trend.
During the formation of the genital system in the foetus, the embryonic halves of the penis may fail to join up, or do so incompletely, resulting in the abnormal siting of the urethral opening. Various theories have been proposed to explain this, including inadequate androgen effect, either inherent or linked (unproven, but suggested) to environmental factors like:
- maternal phytoestrogens (vegetarian diet) during pregnancy,
- iron supplement in pregnancy,
- maternal influenza in pregnancy,
- maternal progestin or stilboestrol use,
- maternal exposure to DDT,
- advanced maternal age, and
- pre-existing maternal diabetes.
Associated abnormalities of the upper genito-urinary tract are uncommon.
Lower tract abnormalities are, however, frequently seen, and include
- undescended testis - often bilateral
- inguinal hernia
- prostate abnormalities predisposing to infection (enlarged utricle)with pseudo-incontinence or even stone formation, and/or
- chordee - an abnormal downward curvature of the penis
This an obvious condition, so no special tests are needed for confirmation. However, a careful physical examination must be done to look for associated, correctible problems, such as undescended testes or inguinal hernias. In cases where the urethral opening is at the base of the penis, or if the genitalia appear otherwise abnormal, screening for intersex conditions is indicated.
Newborns with hypospadias should not be circumcised; the foreskin is preserved for future use in the reconstruction of a normal urethral opening.
Surgery is done by a paediatric urology surgeon with experience in these types of surgery, and is usually done before the child reaches 18 months of age. The outcome is generally very good, both cosmetically and functionally, though somewhat less in those with severe hypospadias.
Specific risks of surgery include scarring, fistula formation, diverticulae and strictures, though these are becoming rare as surgical expertise increases.
(Dr A G Hall)