Kidney Dysplasia

 National Kidney and Urologic Diseases Information Clearinghouse 

U.S. Department 

of Health and 

Human Services 

NATIONAL 

INSTITUTES 

OF HEALTH 

What is kidney dysplasia? 

The kidneys are a pair of bean-shaped 

organs that filter fluid and wastes from the 

blood to form urine. Urine flows from the 

kidneys to the bladder through tubes called 

ureters. Kidney dysplasia is a condition 

that can occur in babies while they are 

growing in the womb. Other terms that 

health care providers and scientists use to 

describe this condition are renal dysplasia 

and multicystic dysplastic kidney (MCDK). 

In kidney dysplasia, the internal structures 

of one or both of the baby’s kidneys do 

not develop normally. Fluid-filled sacs 

called cysts replace normal kidney tissue. 

Kidney dysplasia usually happens in only 

one kidney. A baby with one working 

kidney can grow normally and has few, if 

any, health problems. Babies with kidney 

dysplasia affecting both kidneys generally 

do not survive pregnancy, and those who do 

survive need dialysis and kidney transplant 

very early in life. 

How does kidney 

dysplasia happen? 

Ureters are tubes that grow into the 

kidneys and branch out to form a network 

of tubules that will collect urine when the 

fetus is developing in the womb. In kidney 

dysplasia, the tubules fail to branch out 

completely. The urine that would normally 

flow through small tubules has nowhere to 

go, so it collects inside the affected kidney 

and forms cysts. 

During normal development, the tubules that collect 

urine branch out throughout the baby’s kidneys. 

In kidney dysplasia, the tubules fail to branch out, and 

urine has nowhere to go. The urine collects inside 

the kidney and forms cysts. 
 

What causes kidney 

dysplasia? 

Kidney dysplasia may be caused by the 

mother’s exposure to certain drugs or by 

genetic factors. Pregnant women should 

talk with their health care providers 

before taking any medicine during their 

pregnancy. Drugs that may cause kidney 

dysplasia include prescription medicines, 

such as drugs to treat seizures and blood 

pressure medicines called angiotensinconverting enzyme (ACE) inhibitors and 

angiotensin receptor blockers (ARBs). 

A mother’s use of illegal drugs—such as 

cocaine—can also cause kidney dysplasia 

in her unborn child. 

Kidney dysplasia can also have genetic 

causes. The disorder appears to be an 

autosomal dominant trait, which means one 

parent may pass the trait to a child. When 

kidney dysplasia is discovered in a child, 

an ultrasound examination may reveal the 

condition in one of the parents. 

Several genetic syndromes that affect other 

body systems may include kidney dysplasia 

as one part of the syndrome. A syndrome 

is a group of symptoms or conditions that 

may seem unrelated but are thought to 

have the same cause—usually a genetic 

cause. A baby with kidney dysplasia might 

also have problems of the digestive tract, 

nervous system, heart and blood vessels, 

muscles and skeleton, or other parts of the 

urinary tract. 

Problems of the urinary tract that lead 

to kidney dysplasia might also affect 

the normal kidney. For example, one 

urinary birth defect causes blockage at 

the point where urine normally drains 

from the kidney into the ureter. Another 

birth defect causes urine to flow from the 

bladder back up the ureter, sometimes all 

the way to the kidney. This condition is 

called reflux. Over time, if these problems 

are not corrected, they can damage the one 

working kidney and lead to total kidney 

failure. 

A baby with kidney dysplasia might have other 

urinary problems that affect the normal kidney. 

On the left, urine is blocked from draining out of 

the kidney. On the right, urine flows backward from 

the bladder into the ureter and kidney, a condition 

called reflux. 

What are the signs 

or complications of 

kidney dysplasia? 

The affected kidney may be enlarged 

at birth. Abnormalities in the urinary 

tract may lead to urinary tract infections. 

Children with kidney dysplasia may 

develop high blood pressure, but only 

rarely. Children with kidney dysplasia may 

have a slightly increased risk for kidney 

cancer. Chronic kidney disease and kidney 

failure may develop if the child has urinary 

problems that affect the normal kidney. 

Many children with kidney dysplasia in only 

one kidney have no signs or symptoms. 

2 Kidney Dysplasia 
 

How is kidney 

dysplasia diagnosed? 

Kidney dysplasia is often found during a 

fetal ultrasound, also called a sonogram, 

during pregnancy. Fetal ultrasound uses 

sound waves to create images of the 

baby growing in the womb. However, 

the condition is not always detected 

before the baby is born. After birth, an 

enlarged kidney may be detected during an 

examination for a urinary tract infection or 

other medical condition. 

How is kidney 

dysplasia treated? 

If the condition is limited to one kidney 

and the child has no symptoms, no 

treatment may be necessary. Regular 

checkups should include blood pressure 

measurements, blood tests to measure 

kidney function, and urine testing for 

protein. Usually the child is monitored 

with periodic ultrasounds to look at the 

affected kidney and to make sure the 

other kidney continues to grow normally 

and doesn’t develop any other problems. 

Children with urinary tract infections may 

need to take antibiotics. 

Removal of the kidney should be 

considered only if the kidney 

•	 causes	pain

•	 causes	high	blood	pressure

•	 shows	abnormal	changes	on	

ultrasound 

What is the long-term 

outlook for a child with 

kidney dysplasia? 

Many children with kidney dysplasia in only 

one kidney grow into healthy adults without 

any problems. The dysplastic kidney may 

shrink as the child grows. By age 5, the 

kidney may no longer be visible in x-ray or 

ultrasound examinations. Children and 

adults with only one working kidney should 

have regular checkups for high blood 

pressure and kidney damage. A child with 

urinary problems that lead to kidney failure 

may eventually need a kidney transplant or 

blood-cleaning treatments called dialysis. 

Questions to Ask the 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? 

3 Kidney Dysplasia 
 

 

Points to Remember 

•	 	Kidney	dysplasia	is	a	condition	that	

happens while a baby is growing in 

the womb. 

•	 	Kidney	dysplasia	usually	affects	

only one kidney, making it unable 

to function. 

•	 	Many	people	lead	healthy,	normal	

lives with only one functioning 

kidney. 

•	 	A	child	with	kidney	dysplasia	

affecting both kidneys may not 

survive outside the womb. If the 

child does survive birth, early 

dialysis and kidney transplant will 

be needed. 

•	 The	mother’s	exposure	to	certain	

drugs may cause kidney dysplasia 

in her unborn baby. 

•	 	Kidney	dysplasia	may	have	genetic	

causes and is often part of several 

genetic syndromes that affect other 

body systems. 

•	 	Children	and	adults	with	only	

one working kidney should have 

regular checkups for high blood 

pressure and kidney damage. 

•	 	Children	with	urinary	problems	in	

the normal, or nondysplastic, kidney 

that lead to kidney failure will 

need a kidney transplant or bloodcleaning treatments called dialysis. 

Hope through Research 

Researchers from universities and 

Government agencies are working to 

understand the causes of kidney and 

urinary tract birth defects and to find more 

effective treatments. Through its Pediatric 

Urology Program, the National Institute 

of Diabetes and Digestive and Kidney 

Diseases funds research into bladder and 

urinary tract development. Additionally, 

the National Institute of Child Health 

and Human Development has established 

the Birth Defects Initiative to study the 

underlying causes of birth defects. 

4 Kidney Dysplasia 
For More Information

American Society of Pediatric Nephrology 

3400 Research Forest Drive, Suite B7 

The Woodlands, TX 77381 

Phone: 281–419–0052 

Fax: 281–419–0082 

Email: info@aspneph.com 

Internet: www.aspneph.com

American Urological Association 

Foundation

1000 Corporate Boulevard 

Linthicum, MD 21090 

Phone: 1–866–RING–AUA (746–4282) 

 or 410–689–3700 

Fax: 410–689–3800 

Email: patienteducation@auafoundation.org

Internet: www.auafoundation.org 

 www.UrologyHealth.org

March of Dimes 

1275 Mamaroneck Avenue 

White Plains, NY 10605 

Phone: 914–997–4488 

Email: askus@marchofdimes.com 

Internet: www.marchofdimes.com

National Institute of Child Health 

and Human Development Information 

Resource Center

P.O. Box 3006 

Rockville, MD 20847 

Phone: 1–800–370–2943 

Fax: 301–984–1473 

Email: NICHDInformationResourceCenter

 @mail.nih.gov 

Internet: www.nichd.nih.gov

5 Kidney Dysplasia

You may also find additional information about this 

topic by visiting MedlinePlus at www.medlineplus.gov.

This publication may contain information about medications. When prepared, this publication included 

the most current information available. For updates 

or for questions about any medications, contact 

the U.S. Food and Drug Administration toll-free at 

1–888–INFO–FDA (463–6332) or visit www.fda.gov. 

Consult your doctor for more information.
National Kidney and 

Urologic Diseases 

Information Clearinghouse

3 Information Way 

Bethesda, MD 20892–3580 

Phone: 1–800–891–5390 

TTY: 1–866–569–1162 

Fax: 703–738–4929 

Email: nkudic@info.niddk.nih.gov 

Internet: www.kidney.niddk.nih.gov

The National Kidney and Urologic Diseases 

Information Clearinghouse (NKUDIC) is a service 

of the National Institute of Diabetes and Digestive 

and Kidney Diseases (NIDDK). The NIDDK 

is part of the National Institutes of Health of 

the U.S. Department of Health and Human 

Services. Established in 1987, the Clearinghouse 

provides information about diseases of the kidneys 

and urologic system to people with kidney and 

urologic disorders and to their families, health care 

professionals, and the public. The NKUDIC answers 

inquiries, develops and distributes publications, and 

works closely with professional and patient organizations and Government agencies to coordi nate 

resources about kidney and urologic diseases.

Publications produced by the Clearinghouse are 

carefully reviewed by both NIDDK scientists and 

outside experts. This fact sheet was reviewed by 

the following members of the American Society of 

Pediatric Nephrology Clinical Affairs Committee: 

Deepa Chand, M.D.; Maria Ferris, M.D.; Joseph 

Flynn, M.D.; Keith Lau, M.D.; Tej Mattoo, M.D.; 

Asha Mougdil, M.D.; and Robert Weiss, M.D.

This publication is not copyrighted. The 

Clearinghouse encourages users of this fact 

sheet to duplicate and distribute as many 

copies as desired.

This fact sheet is also available at 

www.kidney.niddk.nih.gov.

U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES

National Institutes of Health

NIH Publication No. 08–6291

July 2008