Posterior urethral valve (PUV) is a congenital anomaly that occurs during fetal development of the urinary tract. Normally in male infants, the urethra forms as an open channel from the bladder to the outside. In PUV, a membranelike tissue, known as a valve, develops in the posterior urethra and obstructs urine flow. The exact trigger for this membrane formation is unknown, but it is present at birth. PUV is not usually inherited and does not follow a clear family pattern, although very rarely more than one child in a family may be affected.

PUV occurs in approximately 1 in 5,000 to 8,000 live male births. It affects only males because this valve structure does not develop in females. PUV is the most common congenital cause of urinary outflow obstruction in male infants.

PUV can present differently depending on the child’s age. Some cases are detected before birth on prenatal ultrasound, while others become apparent after delivery.

In the newborn and infant period:

• Prenatal ultrasound showing enlarged kidneys or bladder
• Little or no urine output after birth
• Abdominal distension from bladder or kidney swelling
• Weak or poor urinary stream
• Fever and irritability due to urinary tract infection
• Poor weight gain or failure to thrive

In older children:

• Recurrent urinary tract infections
• Weak, interrupted, or narrow urinary stream
• Straining or pushing to void
• Daytime urinary incontinence
• Sensation of incomplete bladder emptying
• Frequent urination
• Occasional blood in the urine
• Constipation (due to bladder–bowel interaction)
• High blood pressure in advanced cases

• Voiding cystourethrography (VCUG): A specialized X-ray study in which a catheter delivers contrast into the bladder and images are taken during voiding to visualize the bladder and urethra and confirm the valve.
• Renal and bladder ultrasound: Uses sound waves to assess kidney and bladder anatomy, detect hydronephrosis, and evaluate bladder wall thickness.
• Cystoscopy: A thin, lighted scope is passed through the urethra to directly view and confirm the presence of the valve. It can also be used to treat the valve.
• Urinalysis and culture: Checks for infection markers such as white blood cells and bacterial growth, since UTIs often accompany PUV.
• Uroflowmetry: Measures urinary flow rate, duration, and volume. Postvoid residual urine is assessed by ultrasound to evaluate bladder emptying.

If PUV is not treated, the obstructing membrane prevents normal bladder emptying. Urine retention increases bladder pressure, leading to bladder wall thickening, vesicoureteral reflux, and kidney damage over time.

Treatment depends on the severity of the obstruction and the degree of bladder and kidney involvement. The goals are to relieve the blockage, protect kidney function, and reduce infection risk.

Endoscopic valve ablation:

• Performed under general anesthesia using a cystoscope to cut the obstructing valve membrane.
• This minimally invasive procedure typically allows rapid recovery.

Supportive care:

• Antibiotics to treat or prevent urinary tract infections.
• Bladder management strategies or medication if bladder function is impaired.
• Treatment of constipation, which can worsen bladder pressure.
• Maintaining proper fluid intake and diet.

Pelvic floor rehabilitation:

• After valve ablation, some children may have incomplete bladder emptying or dysfunctional voiding due to pelvic floor muscle tension.
• Pelvic floor therapy helps retrain these muscles, improve bladder emptying, and reduce infection risk.