The first sign of biliary atresia is jaundice, which causes a yellow color to the skin and to the whites of the eyes. Jaundice is caused by the liver not removing bilirubin, a yellow pigment from the blood. Ordinarily, bilirubin is taken up by the liver and released into the bile. However, blockage of the bile ducts causes bilirubin and other elements of bile to build up in the blood.
Jaundice may be difficult for parents and even doctors to detect. Many healthy newborns have mild jaundice during the first 1 to 2 weeks of life due to immaturity of the liver. This normal type of jaundice disappears by the second or third week of life, whereas the jaundice of biliary atresia deepens. Newborns with jaundice after 2 weeks of life should be taken to the doctor to check for a possible liver problem.
Other signs of jaundice are a darkening of the urine and a lightening in the color of bowel movements. The urine darkens from the high levels of bilirubin in the blood spilling over into the urine, while stool lightens from a lack of bilirubin reaching the intestines. Pale, grey, or white bowel movements after 2 weeks of age are probably the most reliable sign of a liver problem and should prompt a visit to the doctor.