horseshoe kidney

Horseshoe kidney is when the two kidneys join (fuse) together at the bottom. They form a U shape like a horseshoe. It is also known as renal fusion. The condition occurs when a baby is growing in the womb, as the baby’s kidneys move into place. Horseshoe kidney can occur alone or with other disorders.

Researchers aren’t sure exactly why horseshoe kidney occurs. It may be caused by a problem with chromosomes. Horseshoe kidney can occur along with some genetic disorders, such as Turner syndrome and Edward syndrome.

The condition happens more often in boys than girls.

In many cases a child has no symptoms. Some children may have nausea or pain in the belly. A child may also have kidney stones. This is a condition in which minerals and proteins form stones in the kidney. They may then block the urinary tract.

Some children may have urinary tract infections (UTIs). UTIs can cause symptoms such as:

• Fever
• Foul-smelling urine
• Sudden need to urinate
• Need to urinate often
• Loss of control of urine (incontinence)
• Pain while urinating
• Trouble urinating

The symptoms of horseshoe kidney can be like other health conditions. Make sure your child sees his or her health care provider for a diagnosis.

The health care provider will ask about your child’s symptoms and health history. He or she may also ask about your family’s health history. He or she will give your child a physical exam. Your child may also have tests, such as:

• Renal ultrasound (sonography). This is a painless test that uses sound waves and a computer to create images of body tissues. During the test, a health care provider moves a device called a transducer over the belly in the kidney area. This sends a picture of the kidney to a video screen. The health care provider can see the size and shape of the kidney. He or she can also see a growth, kidney stone, cyst or other problems.
• Voiding cystourethrogram (VCUG). A VCUG is a type of X-ray that looks at the urinary tract. A thin, flexible tube (catheter) is placed in the urethra. This tube drains urine from the bladder to the outside of the body. The bladder is filled with a liquid dye. X-ray images are taken as the bladder fills and empties. The images will show if there is any reverse flow of urine into the ureters and kidneys.
• Intravenous pyelogram (IVP). This is an imaging test that uses an X-ray to view the urinary tract. Contrast dye is given so that the tract can be seen on film. An IVP also shows the rate and path of urine flow through the urinary tract.
• Blood tests. These look at how well the kidneys are working.
• Urine test. This test checks for chemicals in the urine and signs of infection.

The condition can’t be changed or cured. But a child with no symptoms may not need any treatment. If your child has symptoms or related problems, those will be treated. Your child may be referred to an expert such as:

• Urologist. This is a health care provider who treats problems of the urinary tract and the male genital tract.
• Nephrologist. This is a health care provider who treats problems of the kidneys.

Treatment will depend on your child’s symptoms, age and general health. It will also depend on how severe the condition is.

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

About 1 out of 3 children with horseshoe kidney will have a problem with the heart and blood vessels, nervous system, or genitourinary system. These problems may include:

• Hydronephrosis. This is swelling of the kidneys caused by a buildup of urine. It can happen because of a urinary tract blockage.
• Wilms tumor. This is a tumor of the kidneys that can occur in early childhood.
• Kidney cancer. This is when cells grow uncontrolled into lumps in the kidney.
• Polycystic kidney disease. This disease causes many fluid-filled pouches (cysts) to form inside the kidneys.
• Hydrocephaly. This is extra fluid on the brain.
• Spina bifida. This is a type of neural tube defect, where part of the spinal cord forms abnormally.

Horseshoe kidney can also occur along with other problems with the heart and blood vessels, digestive system or bones.

A child with horseshoe kidney is more at risk for kidney injury. This is because the fused kidneys often sit lower down and closer to the front of the body. A child with horseshoe kidney may not be able to play contact sports. Your child’s health care provider may also advise that your child wear a medical alert bracelet.

Call the health care provider regarding your child's horseshoe kidney if your child has:

• Symptoms that don’t get better, or get worse
• New symptoms