Biliary Atresia in Newborns: Symptoms, Causes, and Treatment
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is biliary atresia?
Biliary atresia is a rare liver condition of newborns and infants in which the bile ducts become inflamed and blocked or fail to form, causing bile to build up and scar the liver. Warning signs include jaundice lasting longer than two weeks and pale stools. The Kasai procedure, ideally before 60 days of age, creates a new drainage pathway. [1] [2]
What the research says
Earlier Kasai surgery was linked to longer native liver survival. In a meta-analysis of nine studies, surgery at a later age was associated with a significantly faster time to liver transplantation (hazard ratio 2.12, 95% CI 1.51-2.97), and the risk ratio for native liver survival comparing surgery at 30 days or younger with 31 days or older was 1.22 (95% CI 1.13-1.31) (Hoshino et al., Eur J Pediatr, 2023) [3].
Surgery at 90 days or younger gave better bile flow and survival with the child's own liver. Across 14 studies involving 3,276 children, those operated on at 90 days or younger had higher jaundice clearance (OR 3.05, 95% CI 2.23-4.17) and better native liver survival (OR 1.72, 95% CI 1.37-2.15) than children older than 91 days, and surgery before 60 days beat 61 to 90 days for native liver survival (OR 1.41, 95% CI 1.18-1.68) (Yang et al., Front Surg, 2022) [4].
A blood test can help tell biliary atresia apart from neonatal hepatitis. Pooling 24 studies and 7,298 participants, serum MMP-7 had a sensitivity of 0.94 and a specificity of 0.88 for biliary atresia; the authors call for assay standardization and age-specific reference ranges (Choudhury et al., Pediatr Surg Int, 2025) [5].
Study details are from PubMed abstracts.
What exactly is biliary atresia?
Biliary atresia is a rare liver condition that affects newborns and infants. It occurs when the bile ducts become inflamed and blocked or fail to form correctly. Bile ducts are slender tubes that carry the digestive fluid bile from the liver to the small intestine. [1]
When bile cannot flow out of the liver, it builds up and causes liver damage and scarring, and eventually progressive, severe scarring known as cirrhosis. [1]
Babies with biliary atresia usually appear healthy at birth. The first sign of illness is often yellowing of the eyes and skin, called jaundice, together with pale stools that last beyond two weeks. [1]
Although many children eventually require a liver transplant, a successful Kasai surgery can delay this need for many years. Some individuals may reach adulthood without ever needing a transplant. [1]
Fact | Detail |
What it is | Blocked or malformed bile ducts that prevent bile from draining out of the liver |
Who it affects | Newborns and infants; about 1 in every 10,000 to 20,000 live births |
Why it matters | The leading cause of liver transplants in children |
Appearance at birth | Babies usually look healthy at birth; signs emerge gradually as bile becomes trapped |
Main surgery | Kasai procedure (hepatoportoenterostomy), ideally before 60 days of age |
Cure? | No. Surgery relieves bile buildup and slows damage but does not cure the condition |
Transplant need | Around 60% to 80% of children eventually need a liver transplant |
What are the symptoms of biliary atresia?
Symptoms of biliary atresia usually appear between ages 2 and 8 weeks. Most babies appear healthy at birth, but as bile becomes trapped in the liver, signs of illness gradually appear. [1]
Healthy newborn stools are usually yellow, green, or brown. Pale, clay-colored stools can be a sign that bile is not reaching the intestines, and may be an early warning sign of biliary atresia or other liver problems. [1]
Common symptoms include:
Jaundice that lasts longer than two weeks after birth. This is one of the earliest and most reliable warning signs. Unlike typical newborn jaundice, which fades as the baby's liver matures, the jaundice of biliary atresia does not improve and may deepen in color.
Pale, gray, or white stools. Bile gives stool its typical brown color, so when bile flow is blocked, stools become light or clay colored. Parents often describe them as “putty colored.”
Dark yellow, tea-like urine. Bilirubin builds up in the blood and passes into the urine.
Swollen belly or firm liver. The liver and spleen may become enlarged when biliary atresia is not detected early.
Poor weight gain or irritability. As liver function declines, babies may feed poorly or fail to gain weight.
How is biliary atresia different from infant jaundice?
Typical newborn jaundice is caused by a temporary buildup of bilirubin and resolves on its own. Jaundice from biliary atresia results from blocked bile ducts and ongoing liver injury. [1]
Persistent yellowing of the skin and eyes, pale stools, and dark urine should always prompt medical evaluation. Because many healthy babies also have mild jaundice early in life, recognizing when it persists or worsens is critical. [1]
What are the types of biliary atresia?
Healthcare professionals sometimes describe biliary atresia as either syndromic or nonsyndromic, depending on whether other birth defects are present. In some babies, biliary atresia occurs along with other structural problems, such as heart defects, spleen problems, or differences in how the intestines are arranged. These babies may need extra tests and specialized care. In most cases, however, biliary atresia occurs without other malformations. [1]
Professionals also classify the condition by where the bile ducts are blocked (the Kasai classification):
Type | Where the blockage is | Key detail |
Type 1 | The main (common) bile duct | The ducts inside the liver are still open |
Type 2 | Higher up, where the right and left bile ducts come together | The smaller ducts inside the liver are still open |
Type 3 | At the duct where bile leaves the liver (porta hepatis), completely blocking the extrahepatic biliary tree | The most common and severe form |
Understanding the type helps healthcare professionals decide what approach may offer the best outcome. [1]
What causes biliary atresia?
Scientists do not yet know exactly what causes biliary atresia, but research shows it likely begins before the baby is born. There is no evidence that it is inherited or caused by anything a parent did or did not do during pregnancy. It also is not something a child with biliary atresia will pass on to their own children. [1]
Researchers believe biliary atresia may be triggered by a mix of factors. These include problems with how the bile ducts form during pregnancy, certain genes, and possibly infections or toxins that affect the baby in the womb. [1]
The more common type appears in healthy-looking babies during the first weeks of life. A less common type, called embryonic or syndromic biliary atresia, happens alongside other birth defects such as heart or spleen problems. [1]
Are there risk factors?
Biliary atresia has no proven, consistent risk factors that predict which babies will develop it. Most cases appear sporadically, meaning they happen by chance in otherwise healthy infants with no family history or known cause. [1]
This is an important point for parents: biliary atresia is nobody's fault, and nothing a parent did during pregnancy is known to cause it.
When should you seek care?
If your baby has jaundice that lasts longer than two weeks, pale or gray stools, or dark urine, make an appointment with your baby's healthcare professional right away. These may be early signs of a liver or bile duct condition such as biliary atresia. [2]
Also mention these to your baby's healthcare professional:
Stools that are pale, gray, or white rather than yellow, green, or brown
Urine that looks dark yellow or tea-like
Poor feeding or poor weight gain
A swollen belly
Speed matters because the surgery that restores bile flow works best when performed early in life, ideally within the first 60 days. The earlier it is performed, the better the outcome. [1]
How is biliary atresia diagnosed?
In most cases, biliary atresia cannot be detected before birth. Routine prenatal ultrasounds usually look healthy. On rare occasions a small or missing gallbladder may be seen, but that alone is not enough to confirm a diagnosis. [2]
The process usually begins when a baby's jaundice lasts longer than two weeks. Diagnosis involves a combination of lab tests and imaging studies, and is usually confirmed through a liver biopsy or a special imaging test done during surgery under anesthesia, called intraoperative cholangiography. [2]
Diagnostic test | What it shows |
Blood tests | Check bilirubin levels; direct (conjugated) bilirubin over 1.0 mg/dL after two weeks of age is especially concerning. GGT is often very high; AST and ALT may be mildly elevated |
MMP7 testing | A newer blood test that measures matrix metalloproteinase-7, a protein often much higher in babies with biliary atresia. Still being studied and not used alone for a final diagnosis |
Ultrasound | May show a very small or missing gallbladder and a bright, cone-shaped “triangular cord sign” near the liver. A newer technique looks for the “duct at the hilum” and, in one study, accurately identified all infants with biliary atresia |
HIDA scan | A small, safe amount of radioactive tracer is given by IV and a camera tracks how the liver and bile ducts handle it. If the tracer does not reach the intestine, bile may not be flowing, though this can occur in other liver conditions too |
Liver biopsy | A tiny tissue sample examined under a microscope may show extra growth of small bile ducts, thick trapped bile called bile plugs, and early scarring called fibrosis |
Intraoperative cholangiogram | Dye is injected directly into the bile ducts and X-rays are taken during a minor surgery. If the dye does not flow into the intestines, the diagnosis is confirmed |
Several other conditions can cause jaundice or pale stools in infants and must be ruled out: neonatal hepatitis, Alagille syndrome, choledochal cyst, alpha-1 antitrypsin deficiency, and progressive familial intrahepatic cholestasis (PFIC), a rare inherited condition that blocks bile flow. [2]
How is biliary atresia treated?
Babies with biliary atresia need early treatment to protect their livers and help bile drain properly. Treatment usually involves surgery; for some babies, treatment is a liver transplant. [2]
The Kasai procedure
The Kasai procedure, also called a hepatoportoenterostomy, is the procedure of choice for biliary atresia. It creates a new pathway for bile to leave the liver by connecting the baby's intestine directly to the liver, bypassing the blocked bile ducts. [2]
During the operation, the surgeon removes the damaged bile ducts located outside the liver. Then a section of the baby's small intestine is carefully connected directly to the surface of the liver, allowing bile to drain straight from the liver into the intestine as it typically would. [2]
The Kasai procedure works best when done early, ideally before 60 days of age. Performing the surgery within this window gives the baby the best chance of restoring bile flow and avoiding or delaying a liver transplant. [2]
Even when the surgery is successful, children still need regular follow-ups. Over time, most children develop liver damage and require additional treatment, including the possibility of a liver transplant later in life. [2]
Liver transplant
Around 60% to 80% of children with biliary atresia eventually need a liver transplant. A transplant may be needed if the Kasai procedure fails to restore bile flow, if liver scarring continues and causes complications such as fluid buildup, poor growth, or bleeding, or if the child develops liver failure. [2]
Some babies need a transplant soon after diagnosis, while others may live for years before needing one. Transplants can offer a long-term solution when the liver no longer functions well. [2]
Long-term follow-up care
Even after surgery, children with biliary atresia need lifelong follow-up with a liver care team. This includes regular lab tests to monitor liver health, nutritional support (especially fat-soluble vitamins A, D, E, and K), and monitoring for signs of liver damage or complications. [2]
With early treatment, good nutrition, and medical follow-up, many children with biliary atresia go on to live active, healthy lives. [2]
How can parents cope with biliary atresia in a newborn?
Learning that your baby has biliary atresia can be overwhelming. You may feel worried, sad, or uncertain about what comes next. With time, many parents find ways to cope and feel more confident in caring for their child. [2]
Learn about your baby's condition. Ask the care team to explain what biliary atresia means, what tests and treatments are planned, and what to expect during recovery.
Lean on your support network. Family and friends can be an important source of strength. Accepting offers of help with meals or childcare can make a real difference.
Connect with others who understand. Many parents find comfort in talking with others who have been through something similar.
Take care of yourself. Rest when you can, eat regularly, and make time for breaks. You will be better able to care for your child when you care for yourself too.
What is the bottom line on biliary atresia in newborns?
Biliary atresia is a rare condition in which a baby's bile ducts are blocked or malformed, trapping bile inside the liver and progressively damaging it. What makes it urgent is timing: the warning signs (jaundice beyond two weeks, pale putty-colored stools, and dark tea-like urine) emerge in the first weeks of life, and the surgery that restores bile flow works best within the first 60 days.
The Kasai procedure is not a cure, and most children will eventually need a liver transplant, but early detection and lifelong follow-up change the trajectory. Many children go on to live active, healthy lives, which is why every pale stool and persistent yellow tint deserves prompt medical attention.
Next steps: If your newborn's jaundice lasts more than two weeks, or you notice pale stools or dark urine, contact a pediatric healthcare professional right away and mention how long the symptoms have been present. If biliary atresia is diagnosed, ask about the timing of the Kasai procedure and about a pediatric liver care team for lifelong follow-up.
FAQ
What is the difference between biliary atresia and normal newborn jaundice?
Typical newborn jaundice is caused by a temporary buildup of bilirubin and resolves on its own. Jaundice from biliary atresia results from blocked bile ducts and ongoing liver injury, and it persists or deepens rather than fading, which is why jaundice lasting beyond two weeks needs medical evaluation.
Why are a baby's stools pale with biliary atresia?
Bile gives stool its typical brown color, so when bile flow is blocked, stools become light, gray, or clay colored, often described as “putty colored.” Pale stools can be an early warning sign of biliary atresia or other liver problems.
Can biliary atresia be detected before birth?
In most cases, no. Routine prenatal ultrasounds usually look healthy; only rarely is a small or missing gallbladder seen, and that alone is not enough to confirm a diagnosis.
Does the Kasai procedure cure biliary atresia?
No. The Kasai procedure relieves bile buildup and slows liver damage, and it works best when performed within the first 60 days of life. But even with successful surgery, most children develop liver damage over time and may eventually need a liver transplant.
What is life like for children treated for biliary atresia?
Around 60% to 80% of children eventually need a liver transplant, though many live for years, or reach adulthood, before needing one. With early treatment, good nutrition including vitamins A, D, E, and K, and lifelong follow-up, many children go on to live active, healthy lives.
Disclaimer: This article is for general informational purposes only and does not constitute medical advice. Always consult a qualified health care provider for individual questions.
Related Reading
Learn more in our guide to Living Donor Liver Transplant: Who Can Donate, Surgery, Risks and Recovery.
HIDA Scan (Hepatobiliary Scan): Purpose, Preparation, Procedure and Results explains the nuclear scan that checks bile flow through the gallbladder and bile ducts.
References
Mayo Clinic Staff. Biliary atresia - Symptoms and causes. Mayo Clinic. February 24, 2026. https://www.mayoclinic.org/diseases-conditions/biliary-atresia/symptoms-causes/syc-20591855
Mayo Clinic Staff. Biliary atresia - Diagnosis and treatment. Mayo Clinic. February 24, 2026. https://www.mayoclinic.org/diseases-conditions/biliary-atresia/diagnosis-treatment/drc-20591859
Hoshino E, et al. Age at surgery and native liver survival in biliary atresia: a systematic review and meta-analysis. Eur J Pediatr. 2023;182(6):2693-2704. PMID 36997770. https://doi.org/10.1007/s00431-023-04925-1
Yang C, et al. Impact of early Kasai portoenterostomy on short-term outcomes of biliary atresia: A systematic review and meta-analysis. Front Surg. 2022;9:924506. PMID 36117834. https://doi.org/10.3389/fsurg.2022.924506
Choudhury P, et al. Serum matrix metalloproteinase-7 (MMP-7) as a Biomarker for differentiating biliary atresia from neonatal hepatitis: evidence synthesis through systematic review and meta-analysis. Pediatr Surg Int. 2025;41(1):265. PMID 40849391. https://doi.org/10.1007/s00383-025-06169-6
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