A. Hypospadias is a congenital defect of the penis, resulting in incomplete development of the anterior urethra, corpora spongiosum, and prepuce (foreskin).

B. Clinically, the hypospadiac urethral meatus does not cause significant symptoms other than a urinary stream that may be deflected in a downward fashion.

C. Hypospadias is also associated with penile curvature and in severe cases may result in infertility secondary to difficulty in semen delivery or associated abnormalities in testicular function.

D. Hypospadias is not associated with an increased risk of urinary tract infection.

E. Severe hypospadias with or without associated cryptorchidism should be evaluated for a Disorder of Sex Development (Chapter 4).

A. At 2 months gestation the male and female genitalia are essentially indistinguishable.

B. Under the influence of androgens, the male external genitalia become masculinized.

C. By the end of the first trimester, approximately 17 to 18 weeks, the penile urethra and accompanying prepuce are completely formed.

D. Abnormalities in this development can lead to hypospadias and associated penile anomalies.

E. In hypospadias, incomplete development of the glandular urethra does not allow the preputial folds to fuse.

F. Consequently, in hypospadias the foreskin is absent on the ventrum and there is excessive foreskin on the dorsal surface (dorsal preputial hood).

A. Hypospadias can be classified as mild, moderate, or severe based on the location of the ectopic urethral meatus along the ventral aspect of the glans or coronal (mild), penile shaft (moderate), or penoscrotal junction, scrotum, or perineum (severe). It is important to take into account associated penile curvature, which will increase the complexity of hypospadias and hence surgical repair.

B. A more useful surgical classification is the location of the meatus after penile straightening or chordee correction at the time of reconstructive surgery.

1. Fifty-five percent of the patients will have anterior hypospadias with the meatus on the glans or subcoronal (Fig. 2-1 A).

2. Thirty percent will have the urethral meatus on the penile shaft (Fig. 2-1 B).

3. Fifteen percent will have the meatus between the perineum and the penoscrotal junction (Fig. 2-1 C).

C. A rare form of hypospadias occurs in less than 1% of patients where the foreskin is circumferential and the ectopic meatus is discovered when taking down the physiologic foreskin adhesions at the time of circumcision. These patients have a wide meatus located near the coronal margin, the so-called megameatus intact prepuce. This can be successfully repaired with and without preservation of the foreskin.

A. Hypospadias occurs in 1 per 250 live male births.

B. There is a 14% incidence in male siblings and an 8% incidence in off-spring of patients with hypospadias.

C. The majority of cases of hypospadias have no known etiology. Extensive research into abnormal androgen metabolism or the levels of the androgen precursors, testosterone and the more potent dihydrotestosterone, has revealed only a small percentage of patients with any abnormalities. A classic example would be the rare patient with 5α-reductase deficiency and associated severe hypospadias.

D. Environmental pollutants or endocrine disruptors have been suggested to cause hypospadias by maternal exposure that is carried to the developing fetus. Case report human data and experimental animal data are cause for concern and further investigation is warranted.

A. Undescended testes occur in approximately 9% of patients with hypospadias.

B. There is an increased incidence of up to 30% in patients with penoscrotal or more severe hypospadias.

C. Inguinal hernias also occur in approximately 9% of patients with hypospadias.

D. A prostatic utricle or müllerian remnant in the posterior urethra is found in a high percentage of patients with severe hypospadias. Prostatic
utricles in hypospadias are typically of no clinical consequence but can make catheterization difficult.

E. Associated urinary tract anomalies are infrequent in patients with isolated hypospadias because the external genitalia are formed embryologically much than the kidneys, ureter, and bladder.