Children born with one kidney (unilateral renal agenesis) are often healthy, don’t have symptoms and don’t need treatment. However, they may develop problems like high blood pressure and kidney disease in adulthood. Newborns with no kidneys (bilateral renal agenesis) usually can’t survive outside the uterus. A gene mutation often causes renal agenesis.
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Renal agenesis occurs when a baby is born with only one kidney or no kidneys. Most people have two kidneys, and you need at least one to live. This condition is congenital, which means it’s present at birth.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
You may better understand this condition when you break down the meaning of its words:
A person may have:
Most people have two kidneys, which are part of the urinary system. Your kidneys help remove wastes from blood, which leave your body when you pee.
An estimated 1 in 2,000 babies has unilateral renal agenesis. Bilateral renal agenesis is less common, affecting about 1 in 8,500 newborns. For unknown reasons, the bilateral type is more common in males.
A gene change or mutation causes many cases of renal agenesis. Researchers have identified at least seven different linked gene mutations. The gene mutation interferes with the fetal formation of the kidneys during the first trimester of pregnancy.
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Less common causes include:
Unilateral renal agenesis is an autosomal dominant disease. This means a child will develop the disease if they inherit a copy of the changed gene from one parent. Often, the parent also has the condition. A parent who has the gene mutation has a 50% chance of passing it to each of their children.
Bilateral renal agenesis is sometimes inherited as an autosomal recessive disease. This means a child must inherit the same altered gene from each parent in order to develop the disease. The parents are carriers of the mutated gene, but they don’t actually have the disease.
When both parents have the mutated gene, each of their children has a:
A child with no working kidneys and underdeveloped lungs (Potter syndrome) will have life-threatening respiratory problems soon after birth.
A child with one working kidney may not have symptoms. When symptoms occur, they include:
Some children with unilateral renal agenesis also have:
A prenatal ultrasound during pregnancy often detects low levels of amniotic fluid (oligohydramnios) that can indicate renal agenesis. This ultrasound can also identify missing kidneys. Low urine output from the fetus affects amniotic fluid levels. Without sufficient fluid, a fetus’s lungs can’t grow and develop properly.
Imaging scans may take place soon after birth to confirm the diagnosis. In some instances, healthcare providers don’t detect the condition until a child is older. The child may have symptoms that require imaging scans. Or a child may get an ultrasound for an unrelated problem like a urinary tract infection (UTI) that leads to an incidental diagnosis of renal agenesis.
Imaging tests for renal agenesis include:
About 4 in 10 fetuses with bilateral renal agenesis die in the uterus before childbirth (a stillbirth). Or they arrive early (a premature birth) before the 37th week of pregnancy. Without kidneys to make urine and amniotic fluid, a fetus's lungs don’t develop properly. Most newborns die from respiratory failure a few hours after childbirth.
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Until recently, a newborn with no kidneys and underdeveloped lungs had little hope of surviving outside of the uterus for more than a few hours. But new experimental treatments offer a reason to have hope. The treatment involves injecting saline (saltwater) solution into the uterus during pregnancy to restore amniotic fluid levels. The fluid allows the fetus’s lungs to develop. After birth, the baby receives dialysis until a kidney transplant procedure can take place. This treatment is still experimental and not widely available.
Unilateral renal agenesis may lead to a premature birth. Your baby may be small and require specialized care in a hospital neonatal intensive care unit (NICU).
Up to half of children born with one kidney develop kidney disease or other problems by the time they’re 30. These problems include:
People with unilateral renal agenesis may need medications to lower blood pressure. You or your child should see a nephrologist (a kidney specialist) for annual or more frequent physical examinations, urinalysis and imaging. Your child may also get these tests:
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Most people with one kidney should follow a kidney-friendly (DASH) diet. This diet reduces sodium and sugar, and increases fiber and potassium.
For children and adults with renal agenesis, these steps can protect kidney health:
If you have a gene mutation linked to renal agenesis, a genetic counselor can discuss ways to lower the risk of passing it to your children. You may have the option to use preimplantation genetic diagnosis (PGD) to identify embryos that don’t have the altered gene. Your provider uses in vitro fertilization (IVF) to implant these embryos into the female reproductive system.
Most people with one kidney lead full, active lives. But some develop kidney problems. It’s important to get regular exams. In the past, infants with no kidneys couldn’t survive. Today, there are experimental therapies that may help a child survive until they’re able to get a kidney transplant.
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Call your healthcare provider if you or your child experience signs of kidney disease, such as:
You may want to ask your healthcare provider:
A child with unilateral renal agenesis only has one kidney. With kidney dysplasia, there are two kidneys but one or both of them are small and/or don’t work well.
A note from Cleveland Clinic
Thousands of people lead productive lives with only one kidney. Still, it can be upsetting to learn that you, your fetus or your older child has renal agenesis. Children born with one kidney (unilateral renal agenesis) are at risk for kidney problems during adulthood. Talk to your child’s healthcare provider about the best ways to protect their kidney health. Bilateral renal agenesis (having no kidneys) is a more serious condition that’s often fatal.
Last reviewed on 09/15/2022.
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