Kidney Dysplasia

Kidney dysplasia, also called renal dysplasia or multicystic dysplastic kidney (MCDK), is a disorder that can occur in babies while they are developing in the womb. In this disorder, the internal structures of one or both of the kidneys do not develop normally. Normal kidney tissues are replaced by cysts, which are fluid filled sacs.

The kidneys are two bean-shaped organs that help filter fluid and wastes from the blood to form urine. Urine from the kidneys flows to the bladder through tubes called ureters.

Kidney dysplasia usually occurs in only one kidney. A baby, with one normal kidney can grow normally with few, if any, health problems. Babies whose both kidneys are affected with the condition generally do not survive pregnancy. Those who do survive will eventually need to undergo dialysis or kidney transplantation very early in life.

What happens in Kidney Dysplasia?

During normal development in the womb, the tubules that collect urine branch out throughout the baby’s kidneys. In kidney dysplasia, however, the tubules fail to branch out completely. Since the urine that normally flows through these small tubules has nowhere to go, it collects inside the affected kidney and forms cysts.

Top of Page

Causes

Kidney dysplasia may occur if the mother is exposed to certain drugs. Prescription medicines, such as drugs to treat seizures and certain blood pressure medications may cause the condition. Such blood pressure medications may include angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers. Also, pregnant women who use illegal drugs such as cocaine may increase the risk of the unborn child to develop kidney dysplasia.

Genetic factors may also play a role in the development of kidney dysplasia. The parent may have passed on the condition to the child.

In some cases, kidney dysplasia occurs as a part of several genetic syndromes that affect other parts of the body as well.

[Top of Page]

Signs and Symptoms and Complications

Most children with kidney dysplasia in only one kidney have no signs or symptoms. In fact, many people lead normal, healthy lives with only one normal kidney.

The child’s affected kidney may be enlarged at birth. Also, urinary tract infections may occur because of abnormalities in the urinary tract.

Rarely, children with the condition may develop high blood pressure. Also, children with kidney dysplasia have a slight increase in risk of developing cancer. If the child has other urinary problems that affect the normal kidney, chronic kidney disease (CKD) or kidney failure may develop.

[Top of Page]

Diagnosis

Often, kidney dysplasia is found during fetal ultrasound during pregnancy. Fetal ultrasound, also called sonogram, makes use of sound waves to produce images of the fetus growing in the mother’s womb. Kidney dysplasia, however, may not always be detected before the baby is born.

After birth, an enlarged kidney may be discovered during routine examination for a urinary tract infection or other health problem.

[Top of Page]

Treatment

Treatment may not be necessary if the condition affects only one kidney, with the other kidney performing normally. However, continuous monitoring of both the affected and unaffected kidneys is necessary. Also, children and adults who have only one kidney should be checked for high blood pressure and kidney damage regularly.

The doctor may prescribe antibiotics if the child develops urinary tract infection.

In some cases, surgical removal of the kidney may be recommended but should be considered only if the kidney:

 causes pain
 causes high blood pressure
 shows abnormal changes as seen on ultrasound.

A child may need to undergo dialysis or kidney transplantation if kidney failure occurs.

[Top of Page]

Here are some helpful questions that you can ask your doctor:

 Does my child have any other problems in the urinary tract?
 Does my child need to take antibiotics to prevent urinary tract infections?
 Will my child need special medical care?
 How often should my child be checked for high blood pressure and kidney damage?
 How often should the dysplastic kidney and the normal kidney be evaluated by ultrasound?

Reference:
National Kidney and Urologic Diseases Information Clearinghouse (June 2008). Kidney Dysplasia (NIH Publication No. 08—6291). National Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD. Web URL: http://kidney.niddk.nih.gov/kudiseases/pubs/kidneydysplasia/index.htm. Accessed: November 19, 2008

[Top of Page]