Biliary atresia is a genetic condition in newborns where part or all of the bile duct is malformed. It requires prompt surgical treatment.

Biliary atresia is a condition that occurs in infants. It’s characterized by the atypical development of the bile ducts. These ducts carry bile from the liver to the gallbladder and small intestine.

Biliary atresia occurs in about 1 in 12,000 babies in the United States. It’s a life threatening condition, but with prompt medical treatment, most babies survive into adulthood. Without treatment, most children need a liver transplant by the age of 2 years.

Keep reading to learn more about biliary atresia, including its symptoms, risk factors, and treatment options.

Medical emergency

Biliary atresia is a medical emergency that requires surgery, ideally before a child is 6–8 weeks old. Most experts recommend testing a child for biliary atresia or other liver problems if they have jaundice that persists beyond 3 weeks.

Biliary atresia has two main types. These are:

  • Biliary atresia without birth defects: This type occurs in more than 80% of babies in the United States. It’s characterized by the absence of other major birth irregularities. Doctors also refer to it as isolated biliary atresia or biliary atresia perinatal.
  • Biliary atresia with birth defects: This type occurs when babies also have birth irregularities affecting other organs, like their heart, intestines, or spleen. It’s also called fetal or embryonic biliary atresia.

Symptoms of biliary atresia usually appear 2–6 weeks after birth. They include the following.


Jaundice is the yellowing of the skin and whites of the eyes due to a buildup of a substance in bile called bilirubin. It’s common in infants during the first 2 weeks of life, but jaundice that lasts beyond 3 weeks can indicate biliary atresia.

Biliary atresia is the most common cause of jaundice in infants, making up about 25–30% of cases.

Read more about newborn jaundice.

Biliary atresia poop

Infants with biliary atresia usually have stools that are:

  • pale
  • light, white, or gray
  • clay colored

These changes occur due to a lack of bilirubin reaching the intestines.

Dark urine

Babies with biliary atresia often have dark urine due to the buildup of bilirubin. Bilirubin reaches the urine when the kidneys filter it out of the bloodstream.

Other signs and symptoms

Signs and symptoms that may appear by 6–10 weeks include:

Without treatment, biliary atresia leads to scarring of the liver (cirrhosis) and eventually liver failure.

Biliary atresia is characterized by the atypical development or absence of all or part of the portion of the bile duct outside the liver. The exact cause of biliary atresia is unknown, but the condition develops before or shortly after birth.

Some factors that scientists have identified as potential causes include:

  • certain gene mutations, potentially including mutations in:
    • PKD1L1
    • CRIPTO
    • LEFTY
    • ARF6
    • EFEMP1
    • GPC
    • NODAL
    • ADD3
  • problems with bile duct development in the womb
  • autoimmune reactions
  • infections, which may include:
    • reovirus type 3

Biliary atresia is not hereditary, which means it doesn’t pass from parents to children.

Biliary atresia only occurs in newborns. Females and newborns of African or Asian heritage seem to have the highest risk. However, differences between ethnic groups and sexes don’t seem to be large.

Biliary atresia can lead to serious compilations, such as:

  • liver failure
  • cirrhosis
  • malnutrition
  • death, without prompt treatment

Doctors diagnose biliary atresia with a combination of tests. These tests may include:

  • asking about your infant’s medical and family history
  • performing a physical exam, during which a doctor:
    • looks for signs of jaundice
    • looks for signs of birth irregularities
    • checks the color of their stool and urine
  • running blood tests
  • doing a liver biopsy
  • conducting imaging tests, like a liver ultrasound or hepatobiliary scan

The preferred treatment for biliary atresia is a type of surgery called the Kasai procedure. This procedure can slow liver damage and prevent complications. It tends to be more effective the earlier a surgeon performs it.

During the procedure, a surgeon removes the damaged part of the bile duct located outside the liver. They then use a loop of the small intestine to replace the bile duct so that bile flows directly from the liver to the small intestine.

It usually takes about 3 months for a doctor to judge whether the procedure was successful.

Biliary atresia is the most common reason for liver transplants in children. Almost all babies will need a liver transplant by the age of 2 years if they don’t receive surgery. Even with surgery, about half will need a liver transplant by 2 years, and two-thirds will need one during childhood. About half of people who don’t need a transplant in childhood will need one in adulthood.

It’s critical to get medical attention as soon as possible if you believe a child has a liver problem. Ideally, surgery for biliary atresia should take place before the age of 6–8 weeks.

Without surgical treatment, most infants develop cirrhosis within 6 months and liver failure within 1 year. Fewer than 10% of children who don’t receive treatment live past the age of 3 years.

With the Kasai procedure, the majority of children live into adulthood.

Here are some frequently asked questions that people have about biliary atresia.

What are the first symptoms of biliary atresia?

Early symptoms of biliary atresia include jaundice, pale stools, and dark urine.

Can you prevent biliary atresia?

Doctors don’t know why biliary atresia develops or how to prevent it. You can improve the course of the condition by seeking prompt surgical treatment.

Biliary atresia requires prompt surgical treatment.

Most experts recommend contacting a doctor if a child has jaundice that persists for longer than 3 weeks after birth. Seeking surgery early gives a child the best chance of avoiding life threatening complications.