Multicystic Dysplastic Kidney

Multicystic dysplastic kidney is a condition in which the kidney is made up of multiple fluid-filled cysts instead of normal kidney tissue.

The cysts that grow in place of the normal tissue are in varying sizes and often occur in clusters, giving the appearance of a bunch of grapes rather than the normal kidney shape.

Because the cysts replace normal kidney tissue, the kidney is unable to function properly.

Multicystic dysplastic kidney is a congenital condition, meaning it is present at birth. It can affect one kidney (unilateral) or in rare cases both kidneys (bilateral).

The condition is also referred to by other names, including kidney dysplasia, renal dysplasia, multicystic kidney and multicystic renal dysplasia.

Cause

Multicystic dysplastic kidney occurs during fetal development when the kidney – an organ known for its complex development process – doesn’t form as it should. The cause is unknown.

In rare cases the condition is genetic, meaning it runs in families. Most often it occurs at random.

How does multicystic dysplastic kidney affect my baby?

The kidneys serve as a filter, removing waste and extra fluid from our blood. That waste and excess fluid form urine. Kidney function is necessary for survival.

In most cases, only one of the baby’s kidneys is affected. The normal, healthy kidney will typically grow larger and perform the work of two kidneys. Over time, the abnormal kidney usually shrinks until it disappears. The child normally doesn’t have any symptoms.

Potential complications of unilateral multicystic dysplastic kidney include:

• Urinary tract infections (UTIs)
• Urinary tract defects that block the flow of urine (ureteropelvic junction obstruction) or cause the backward flow of urine (vesicoureteral reflux), leading to fetal hydronephrosis, or swelling of the baby’s normal kidney  
• Hypertension (high blood pressure)
• Mild proteinuria (increased protein in the urine caused by kidney damage)
• Infection
• Renal tumors (kidney cancer), rarely

If both kidneys are affected, the condition is typically incompatible with life. Without functioning kidneys, the fetus is unable to produce urine, a primary component of amniotic fluid, the fluid that surrounds the baby in the womb. A lack of amniotic fluid (known as oligohydramnios) can cause severe complications, including underdeveloped lungs (pulmonary hypoplasia) that can’t support the baby’s oxygen needs at birth, deformities of the limbs and face caused by compression in the womb (known as Potter sequence), stillbirth, and neonatal death.

Diagnosis

During pregnancy

Multicystic dysplastic kidney is typically diagnosed during a routine prenatal ultrasound that detects an abnormality in the fetal kidney(s). On imaging, instead of a normal kidney shape, the affected kidney may resemble a bunch of grapes. Imaging may also reveal other structural abnormalities in the urinary tract that affect the flow of urine.

If the condition is bilateral, additional ultrasound findings may include a severely low level of amniotic fluid and other physical deformities in the fetus caused by a lack of amniotic fluid.

A diagnosis of multicystic dysplastic kidney during pregnancy enables your family and your healthcare team to plan ahead for the specialized treatment your baby may need at birth.

After birth

In some cases the condition is not detected until after birth. During a physical exam of the newborn, the kidney with cysts may feel like a lump or mass in the child’s abdomen.

Because there are no symptoms, it is possible that the defect may go undetected until later in the child’s life, when imaging is performed for another health issue. Or the multicystic dysplastic kidney may shrink and vanish before it can be diagnosed.   

Specialized Evaluation and Prenatal Care

If multicystic dysplastic kidney is diagnosed or suspected during pregnancy, you may be referred to a fetal center for further evaluation.

At Texas Children’s Fetal Center, we arrange for you to visit as quickly as possible for a comprehensive assessment by a team of specialists experienced in diagnosing and treating congenital kidney conditions, including maternal-fetal medicine physicians (OB/GYNs specializing in high-risk pregnancies), fetal imaging experts, pediatric nephrologists, genetic counselors, and neonatologists. 

Additional testing may include:

• High-resolution anatomy ultrasound to examine the kidneys, confirm the diagnosis, and look for other defects
• Ultra-fast MRI for a more detailed view of fetal anatomy
• Fetal echocardiogram to evaluate the baby’s heart
• Amniocentesis and chromosomal analysis to identify any chromosomal anomalies

Following this thorough evaluation, our specialists will meet with you about the results, discuss your baby’s prognosis, and answer any questions your family has, to help you make the most informed decisions regarding your child’s care and treatment.

Mother and baby will be closely monitored throughout pregnancy with more frequent ultrasounds to assess fetal growth and watch for signs of complications, including a low amniotic fluid level.

Delivery

We recommend delivery at a center with the expertise and resources to treat babies with congenital kidney conditions, including the highest level neonatal intensive care unit (NICU), if needed.

Delivery and postnatal care should be carefully planned and coordinated across a team of fetal specialists, neonatologists and pediatric nephrologists experienced in treating these birth defects.

Our Fetal Center team works closely with specialists from Texas Children’s Renal Service, one of the largest programs in the world for the treatment of children with congenital and acquired kidney diseases. Here, the pediatric specialists treating your baby have been an integral part of their care team since before birth.

Treatment After Birth

Babies with multicystic dysplastic kidney will undergo a thorough physical exam and testing at birth to evaluate the abnormal kidney, assess kidney function, and look for any associated defects.  

There is no treatment for multicystic dysplastic kidney. In most cases, the affected kidney will shrink over time and eventually disappear, leaving the child with one healthy kidney performing the work of two kidneys. If instead the malformed kidney grows larger or shows signs of complications, surgery may be required to remove the kidney, a procedure known as a nephrectomy.

Children who have associated defects in the urinary tract may require treatment for those abnormalities.

All children born with multicystic dysplastic kidney require ongoing monitoring by a pediatric nephrologist experienced in this congenital condition, including:

• Regular ultrasounds to evaluate the kidneys and look for early signs of complications
• Blood pressure monitoring to check for hypertension (high blood pressure)
• Urine and blood testing to assess kidney function

Your child may be advised to avoid contact sports or use protective gear to prevent injury to the remaining kidney.

Children born with bilateral multicystic dysplastic kidney (both kidneys are affected) rarely survive after birth due to pulmonary hypoplasia, where the lungs are too underdeveloped to support the baby’s oxygen needs. For those who do survive, long-term dialysis is necessary until a kidney transplant may be possible. Dialysis is a treatment that performs the function of the kidneys, filtering waste and extra fluid from the blood.

Postnatal Care Team

While the needs of each child varies based on their condition, your baby’s postnatal care team may include:

• Neonatologist
• Pediatric nephrologist
• Pediatric urologist
• Genetic counselor

Why Texas Children’s Fetal Center?

• A single location for expert maternal, fetal and pediatric care. At Texas Children’s Hospital, mother and baby receive the specialized care required for the diagnosis and treatment of multicystic dysplastic kidney all in one location, for highly coordinated care and treatment planning.
• A skilled, experienced team with proven outcomes. We have a dedicated team of maternal-fetal medicine specialists, fetal imaging experts, pediatric nephrologists, genetic counselors, neonatologists and others who work in concert to care for you and your baby every step of the way, using proven protocols we’ve developed over the years. With their combined expertise and unified approach, this team offers the best possible care for pregnancies involving multicystic dysplastic kidney.
• We care for your child’s needs at every stage of life. Our comprehensive approach starts with your first prenatal visit and continues through delivery, postnatal care, and childhood, thanks to one of the nation’s leading teams of fetal and pediatric specialists.

Videos

• Texas Children’s Fetal Center: Our care began before he/she was born

Additional Resources

• 6 things to consider when choosing a fetal center