Learning that your baby has — or may develop — a kidney condition can be overwhelming. If you’re feeling fear and uncertainty about your child’s future, you’re not alone. Kidney disease in babies is rare, but it does happen — and there are steps you can take to help your child get the best possible care.

In this article, we’ll walk you through the basics of rare kidney disease in babies. You’ll learn about the different types, what symptoms to watch out for, and how doctors diagnose kidney disease in babies and young children. We’ll also discuss what treatment options are available for your child.

How Common Are Kidney Problems in Babies?

Most parents don’t expect their newborn to have a kidney condition, but for some families, it becomes part of their child’s journey from the start. Many of these conditions fall under a group called congenital anomalies of the kidney and urinary tract (CAKUTs) — structural issues that develop before birth. CAKUTs are among the more common birth defects, with global estimates ranging from about 0.4 to 4 cases per 1,000 births.

Some CAKUTs, like mild hydronephrosis (swelling of the kidney), may not require much treatment. Others can lead to more serious health problems later on, including chronic kidney disease or kidney failure.

Genetic Kidney Diseases

There are several different types of kidney disease in babies. Some types are genetic, which means they run in families. Others are caused by abnormalities in how the kidney or urinary tract formed during pregnancy.

Below, we’ll cover some of the most common genetic kidney diseases in babies in more detail.

Polycystic Kidney Disease

Polycystic kidney disease (PKD) is a genetic condition that causes cysts (small, fluid-filled sacs) to grow inside the kidneys. Over time, these cysts can become large and damage the kidneys, making it harder for them to filter waste from the blood. PKD is serious: Without treatment, it can lead to chronic kidney disease or kidney failure.

There are two main types — autosomal recessive PKD (ARPKD) and autosomal dominant PKD (ADPKD).

Autosomal recessive PKD is the type that often shows up in babies and young children. In severe cases, ARPKD can be seen before birth on an ultrasound. Babies with ARPKD may have large, swollen kidneys and trouble breathing. They may also have lung or liver problems. This condition happens when both parents pass on a mutated (changed) gene, even if they don’t have symptoms themselves. As many as a third of children with ARPKD will need a kidney transplant or dialysis (machine-assisted blood filtration).

Autosomal dominant polycystic kidney disease is far more common than ARPKD but usually causes symptoms later in life. However, signs may appear in infancy or childhood, especially if there’s a family history of the disease. ADPKD is passed down when just one parent carries the gene change.

Alport Syndrome

Alport syndrome is also a genetic condition, one that affects the glomeruli (the kidney’s filters). It’s caused by mutations in genes that help produce a protein called collagen, which is needed for healthy kidneys, ears, and eyes. Consequently, children with Alport syndrome may also develop hearing loss or vision problems.

There are a few different types of Alport syndrome:

• Autosomal dominant Alport syndrome is most common. It is usually milder but may still lead to kidney failure.
• X-linked Alport syndrome tends to cause more severe symptoms and faster kidney damage in males than females, according to the American Kidney Fund.
• Autosomal recessive Alport syndrome affects males and females equally, according to the American Kidney Fund, and often causes faster disease progression.

Treating Alport syndrome usually involves ongoing monitoring and strategies for treating the symptoms.

Nephrotic Syndrome

Nephrotic syndrome isn’t a single disease but rather a group of symptoms that show the kidneys aren’t working as they should. The main issue is damage to the glomeruli. When these filters get injured, it causes the kidneys to leak too much protein, leading to proteinuria (excess protein in the urine). Nephrotic syndrome is rare, developing in fewer than 5 in 100,000 children worldwide each year.

In infants, nephrotic syndrome can be congenital (appearing between birth and 3 months of age) or infantile (appearing between 3 and 12 months of age). Childhood nephrotic syndrome appears in children 12 months or older. In childhood nephrotic syndrome, there are many causes that will need to be looked for. Edema (swelling caused by fluid buildup) — especially around the eyes, abdomen, or legs — is usually one of the first signs.

Some babies may also seem tired, not eat well, or have foamy urine. Muscle cramps, diarrhea or nausea, or blood in the urine can also happen.

Many children are treated with steroids to reduce protein loss. If those don’t help, other immune-suppressing medications might be tried next. Children with severe or genetic forms may need:

• Albumin infusion to replace lost blood protein
• Diuretics to help the kidneys remove extra fluid
• Dialysis, in some cases, to filter the blood

If kidney function continues to worsen, a kidney transplant may be needed eventually.

Congenital Kidney Abnormalities

Some kidney problems in babies begin before birth. These are called congenital abnormalities, meaning they happen during development in the womb. Congenital kidney and urinary tract problems are among the most common birth defects seen on prenatal (before birth) ultrasounds.

Below we discuss some types of congenital abnormalities.

Multicystic Dysplastic Kidney

In multicystic dysplastic kidney, one of the baby’s kidneys doesn’t develop normally. It’s often filled with cysts rather than healthy kidney tissue. The affected kidney doesn’t work and may shrink or disappear over time. If the other kidney is healthy, most children live normal lives with regular monitoring.

Posterior Urethral Valve

Posterior urethral valve (PUV) is a condition that affects only males, according to Cleveland Clinic. It involves a blockage in the urethra (the tube that carries urine out of the body). This blockage can cause urine to back up into the bladder and kidneys, leading to swelling or kidney damage. PUV can often be detected before birth. Surgery is usually needed to remove the blockage and protect kidney function.

Renal Hypodysplasia

Renal hypodysplasia can happen if the kidneys are smaller than normal or didn’t develop normally in the womb. The child’s kidneys may not filter blood properly, which can lead to kidney problems over time.

Renal Agenesis

Renal agenesis is when one or both kidneys fail to form during pregnancy. Babies with unilateral renal agenesis (only one kidney) can often live healthy lives. However, in cases of bilateral renal agenesis (both kidneys are missing), the condition is fatal. About 1 in every 2,000 babies has renal agenesis in one kidney. Bilateral renal agenesis occurs in about 1 in 8,500 babies.

Vesicoureteral Reflux

Vesicoureteral reflux means the urine flows backward from the bladder into the kidneys. This can lead to urinary tract infections and kidney damage. Mild cases may resolve on their own. However, more serious cases may require surgery or medication to prevent infections.

Working With a Specialist

If your baby has a kidney condition, it’s important to work with a pediatric nephrologist. A nephrologist is a doctor who specializes in kidney care and kidney diseases. Pediatric nephrologists are trained to treat babies and children with all types of rare childhood kidney diseases.

Following up-to-date guidelines, this specialist will help guide your baby’s treatment, monitor their kidney function, and adjust care as they grow up. They may also work with other health experts, such as dietitians and genetic counselors, to support your baby’s kidney health.

Talk With Others Who Understand

MyKidneyDiseaseTeam is the social network for people with kidney disease and their loved ones. On MyKidneyDiseaseTeam, members come together to ask questions, give advice, and share their stories with others who understand life with kidney disease.

Has your baby been diagnosed with a rare kidney disease? Share your experience in the comments below, or start a conversation by posting on your Activities page.