Hypospadias

How hypospadias develops

During weeks 8 to 14 of pregnancy, folds of tissue on the underside of the developing penis normally fuse to form the urethra and bring its opening to the tip. In hypospadias, this fusion stops early. Development of the foreskin and the tissue under the penis is also affected.

Types

Causes and risk factors

The cause is usually unknown, and likely involves a combination of genes and hormone exposure in early pregnancy. Risk factors include:

• family history: a brother or father with hypospadias
• low birth weight and being small for gestational age
• pregnancies conceived with assisted reproduction (IVF)
• maternal age over 35 and obesity
• maternal exposure to some hormones or endocrine-disrupting chemicals (evidence is mixed)

Associated conditions

• chordee: downward curvature of the penis, more common in proximal types
• hooded foreskin: extra foreskin on top, missing underneath
• undescended testes
• inguinal hernia
• differences of sex development (DSD): especially when hypospadias is severe and testes cannot be felt. This needs hormonal and genetic testing. Congenital adrenal hyperplasia must be considered

Symptoms and diagnosis

Hypospadias is usually spotted on the newborn examination. Signs:

• urethral opening not at the tip
• downward or sideways spraying urine stream (in older boys)
• penile curvature during erections
• incomplete foreskin

Most boys need no tests. Severe forms, or hypospadias with undescended testes, need chromosome analysis, hormone tests and sometimes ultrasound.

Important: circumcision should be avoided before repair, because the foreskin is often used to reconstruct the urethra.

Treatment

A pediatric urologist reviews the baby and plans surgery.

Timing

Repair is usually done between 6 and 18 months of age, in line with American Academy of Pediatrics guidance on genital surgery timing. Some surgeons use short-term hormone treatment (testosterone) before surgery to enlarge the penis in smaller babies.

What surgery involves

• straightening the penis if there is chordee
• creating a new urethra (urethroplasty) to bring the opening to the tip
• reshaping the head of the penis
• repairing or removing the foreskin (circumcision or foreskin reconstruction)

Distal repairs are usually one operation, often as day surgery. Proximal types may need two stages several months apart.

After surgery

• a catheter or stent may stay in the urethra for several days
• a dressing on the penis
• pain relief and sometimes antibiotics
• double diapers to protect the catheter
• avoid straddle toys for a few weeks

Complications

• urethrocutaneous fistula: a small hole where urine leaks along the shaft, the most common complication
• meatal stenosis: narrowing of the new opening
• urethral stricture: narrowing along the urethra
• wound breakdown
• persistent or recurrent curvature
• diverticulum: a pouch in the urethra

Complication rates are low for distal repairs and higher for proximal ones. Many complications can be fixed with further surgery. Boys should be followed through puberty.

Outlook

Most boys have a straight penis, a good urine stream and normal-looking genitals after surgery. Fertility and sexual function are usually normal, especially for distal hypospadias. Severe forms may have more long-term issues and benefit from follow-up into adulthood.

Frequently asked questions

What is hypospadias?

Hypospadias is a birth defect in which the opening of the urethra is on the underside of the penis instead of at the tip. It often comes with a downward bend of the penis and an incomplete foreskin.

What causes hypospadias?

The exact cause is usually unknown. It likely involves a mix of genetic and hormonal factors during early pregnancy. Family history, low birth weight, IVF conception and older maternal age are associated with higher risk.

When should hypospadias be repaired?

Surgery is usually done between 6 and 18 months of age. This timing balances surgical ease, healing and the child's emotional development, and avoids awareness of the operation.

Can a baby with hypospadias be circumcised?

Not before repair. The foreskin is often needed to reconstruct the urethra, so circumcision should be avoided until a pediatric urologist has assessed the baby and planned surgery.

Will hypospadias affect fertility or sexual function?

Most boys with repaired hypospadias, especially distal types, have normal sexual function and fertility as adults. Severe forms or those associated with other conditions may have more challenges and benefit from long-term follow-up.