What are posterior urethral valves in children?

Posterior urethral valves are a problem with the urethra in a boy. The urethra is the tube that drains urine from the bladder to the outside of the body. Posterior urethral valves are small leaflets of tissue in the urethra. They have a narrow, slit-like opening. The valves partly block urine flow because not enough urine can get through them to leave the body. This causes a reverse flow of urine. This can harm the urethra, bladder, ureters, and kidneys. They become too full of urine and swell. This leads to tissue damage. Posterior urethral valves are the most common cause of severe urinary tract blockage in children.

What causes posterior urethral valves in a child?

Experts believe that posterior urethral valves happen early in a baby boy's growth in the uterus. The valves occur in about 1 in 5000 to 8,000 baby boys. They are believed to happen by chance. But some cases have been seen in twins and siblings. This means a gene may be the cause.

What are the symptoms of posterior urethral valves in a child?

Symptoms can be a bit different for each child. They may be mild to severe. The most common symptoms include:

• An enlarged bladder that can be felt through the belly

• Pain when urinating

• Weak urine stream

• Feeling the need to urinate often

• Bed-wetting or pants wetting after toilet training

• Poor weight gain

• Urinary tract infection (rare unless there is a blockage)

The symptoms of posterior urethral valves can seem like other health conditions. Have your child see his healthcare provider for a diagnosis.

How are posterior urethral valves diagnosed in a child?

Posterior urethral valves are often diagnosed by fetal ultrasound while a woman is still pregnant.

A child diagnosed later often has urinary tract infections. The healthcare provider will ask about your child’s symptoms and health history. They will give your child a physical exam. Your child may also have tests, such as:

• Abdominal ultrasound.  This imaging test uses sound waves and a computer to create images of blood vessels, tissues, and organs. The test is used to view internal organs as they work. It also looks at blood flow through vessels.

• Voiding cystourethrogram. This is a type of X-ray to look at the urinary tract. The healthcare provider puts a thin, flexible tube (catheter) in the urethra. They fill the bladder with a liquid dye. The provider takes X-ray images as the bladder fills and empties. The images show if there is any reverse flow of urine into the ureters and kidneys.

• Cystoscopy.  This test uses a small, flexible tube with a light and a camera lens at the end (cystoscope). The scope is used to look inside part of the urinary tract. The healthcare provider may take tissue samples from inside the urinary tract for testing.

• Blood test. This test may be done to check your child's electrolytes and kidney function.

How are posterior urethral valves treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how serious the condition is. Your child may see a urologist. This is a healthcare provider who treats the urinary tract and the male genital tract. Treatment may include:

• Supportive care.  At first, treatment may focus on easing your child's symptoms. If your child has a UTI, is dehydrated, or has electrolyte problems, these conditions will be treated first. Your child may have a catheter placed in their bladder. This is a thin, flexible tube that is put into the penis through the urethra and is gently moved up into the bladder. Your child may also be given antibiotics and IV (intravenous) fluids.

• Cystoscopic ablation.  This procedure is done to remove the valves and other blockages. It’s done with a small, flexible tube with a light and a camera lens at the end (cystoscope).

• Vesicostomy. The healthcare provider makes a small opening in the bladder through the belly. The opening is fixed at a later time when the valves can be cut more safely.

Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all treatments.

What are possible complications of posterior urethral valves in a child?

About 1 in 3 boys with posterior urethral valves may have some long-term kidney failure that may need to be treated. The outlook for the condition is better when it’s found early.

When should I call my child’s healthcare provider?

Call the healthcare provider if your child has:

• Difficulty with urination, such as dribbling or weak stream

• Fever

• Symptoms that don't get better, or get worse

• New symptoms

Key points about posterior urethral valves in children

• Posterior urethral valves are a problem with the urethra in a boy. The urethra is the tube that drains urine from the bladder to the outside of the body.

• These valves are small leaflets of tissue in the urethra. They partly block urine flow because not enough urine can get through them to leave the body. This causes a reverse flow of urine.

• These valves can harm the urethra, bladder, ureters, and kidneys. They become too full of urine and swell. This leads to tissue damage.

• These valves likely happen early in the growth of a baby boy in the uterus.

• They are often diagnosed by fetal ultrasound while a woman is still pregnant.

• Treatment may include removing the valves with surgery.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s healthcare provider after office hours, and on weekends and holidays. This is important if your child becomes ill and you have questions or need advice.