Later in life, sexual function may be hampered if the abnormality restricts semen delivery. Other problems include curvature of the penis and psychological stress due to the abnormal appearance of the genitals. Disrupted hormone signaling may contribute to the defect. A boy's urethra forms when two folds of skin fuse to form a tube during embryonic development. Testosterone is crucial for this event, which takes place between weeks 8 and 12 of gestation.
Incomplete fusion can leave a hole further down the shaft of the penis in an abnormal spot.
Clinical studies show that some boys with hypospadias have defects in their testosterone metabolism or testosterone receptors. This suggests that hypospadias can result from altered levels of the sex hormones that guide development of the genitalia. Surgery to correct the problem is highly successful, and can usually be accomplished with a single operation. The best time to perform the operation is when the baby is between 6 and 15 months of age. The recent CDC study is the first to report an increase in hypospadias outside of Europe.