Kidney Dysplasia?

What is kidney dysplasia?
Kidney dysplasia is a condition in which the internal structures of one or both of a fetus’ kidneys do not develop normally while in the womb. During normal development, two thin tubes of muscle called ureters grow into the kidneys and branch out to form a network of tiny structures called tubules. The tubules collect urine as the fetus grows in the womb. In kidney dysplasia, the tubules fail to branch out completely. Urine that would normally flow through the tubules has nowhere to go. Urine collects inside the affected kidney and forms fluid-filled sacs called cysts. The cysts replace normal kidney tissue and prevent the kidney from functioning.

What are the kidneys and what do they do?
The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of the spine. Every day, the two kidneys filter about 120 to 150 quarts of blood to produce about 1 to 2 quarts of urine, which is composed of wastes and extra fluid. Children produce less urine than adults—the amount they produce depends on their age. The urine flows from the kidneys to the bladder through the two ureters, one on each side of the bladder. The bladder stores urine. The muscles of the bladder wall remain relaxed while the bladder fills with urine. As the bladder fills to capacity, signals sent to the brain tell a person to find a toilet soon. When the bladder empties, urine flows out of the body through a tube called the urethra, located at the bottom of the bladder.

What causes kidney dysplasia?
Genetic factors can cause kidney dysplasia. Genes pass information from both parents to the child and determine the child’s traits. Sometimes, parents may pass a gene that has changed, or mutated, causing kidney dysplasia.

Genetic syndromes that affect multiple body systems can also cause kidney dysplasia. A syndrome is a group of symptoms or conditions that may seem unrelated yet are thought to have the same genetic cause. A baby with kidney dysplasia due to a genetic syndrome might also have problems of the digestive tract, nervous system, heart and blood vessels, muscles and skeleton, or other parts of the urinary tract.

A baby may also develop kidney dysplasia if his or her mother takes certain prescription medications during pregnancy, such as some used to treat seizures and high blood pressure. A mother’s use of illegal drugs, such as cocaine, during pregnancy may also cause kidney dysplasia in her unborn child.

How common is kidney dysplasia?
Kidney dysplasia is a common condition. Scientists estimate that kidney dysplasia affects about one in 4,000 babies.1 This estimate may be low because some people with kidney dysplasia are never diagnosed with the condition. About half of the babies diagnosed with this condition have other urinary tract defects.2

Who is more likely to develop kidney dysplasia?
Babies who are more likely to develop kidney dysplasia include those

whose parents have the genetic traits for the condition
with certain genetic syndromes affecting multiple body systems
whose mothers used certain prescription medications or illegal drugs during pregnancy
What are the signs of kidney dysplasia?
Many babies with kidney dysplasia in only one kidney have no signs of the condition. In some cases, the affected kidney may be enlarged at birth and may cause pain.

How is kidney dysplasia diagnosed?
Health care providers may be able to diagnose kidney dysplasia during a woman’s pregnancy using a fetal ultrasound, also called a fetal sonogram. Ultrasound uses a device, called a transducer, that bounces safe, painless sound waves off organs to create an image of their structure. Fetal ultrasound is a test done during pregnancy to create images of the fetus in the womb. A specially trained technician performs the procedure in a health care provider’s office, an outpatient center, or a hospital, and an obstetrician or a radiologist interprets the images. An obstetrician is a doctor who specializes in pregnancy and childbirth. A radiologist is a doctor who specializes in medical imaging. The patient—in this case, the fetus’ mother—does not need anesthesia for this procedure. The images can show defects in the fetus’ kidneys and other parts of the urinary tract.

How can kidney dysplasia be prevented?
Researchers have not found a way to prevent kidney dysplasia caused by genetic factors or certain genetic syndromes. Pregnant women can prevent kidney dysplasia by avoiding the use of certain prescription medications or illegal drugs during pregnancy. Pregnant women should talk with their health care provider before taking any medications during pregnancy.

Eating, Diet, and Nutrition
Researchers have not found that eating, diet, and nutrition play a role in causing or preventing kidney dysplasia.

Clinical Trials
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.