Infants with biliary atresia usually appear healthy at birth. Most often, symptoms develop within the first two weeks to two months of life. The majority of children with jaundice undergo a series of tests to distinguish biliary atresia from other conditions.
Your doctor will perform a physical exam and will look for or ask questions about the following: jaundice; dark urine; light or pale colored stools; distended abdomen; poor weight gain.
A variety of blood tests can be used to assess liver function. They include:
- Liver enzyme tests (AST, ALT, GGT) — Elevated levels of liver enzymes can alert physicians to liver damage or injury, since the enzymes leak from the liver into the bloodstream under these circumstances.
- Bilirubin — Bilirubin is produced by the liver and is excreted in the bile. Elevated levels of direct or conjugated bilirubin often indicate an obstruction of bile flow or a defect in the processing of bile by the liver.
- Albumin, total protein, and globulin — Below-normal levels of proteins made by the liver are associated with many chronic liver disorders.
- Clotting studies, such as prothrombin time (PT) and partial thromboplastin time (PTT) — Tests that measure the time it takes for blood to clot may be used to diagnose biliary atresia. Blood clotting requires vitamin K and proteins made by the liver. Liver cell damage and bile flow obstruction can both interfere with proper blood clotting.
- Infectious, genetic and metabolic studies — Tests on sweat, blood and urine may be done to look for other causes of liver problems that sometimes look very similar to biliary atresia.
A tissue sample is taken from your child's liver and examined for abnormalities, allowing biliary atresia to be distinguished from other liver problems.
Operating room diagnosis
In some cases, a cholangiogram is performed in the operating room. This is an X-ray imagining study performed by a surgeon in the operating room to determine if there is blockage of bile flow in the ducts leaving the liver.