Biliary atresia

Definition:

An obstruction of the bile ducts caused by their failure to develop normally before birth (in utero).

Causes, incidence, and risk factors:

Biliary atresia is caused by the abnormal and inadequate development of the bile ducts inside or outside the liver. The purpose of the biliary system is to remove waste products from the liver, and to carry bile salts necessary for fat digestion to the small intestine. In this condition, bile flow from the liver to the gallbladder is blocked. This can lead to liver damage and cirrhosis of the liver, which, if not treated, is eventually fatal.

Newborns with this condition may appear normal at birth but persistent jaundice develops by the 2nd or 3rd week of life. The infant may gain weight normally for the 1st month, then weight loss and irritability develop accompanied by increasing levels of jaundice. It is not known why the biliary system fails to develop normally.

The incidence of biliary atresia is approximately 1 out of 20,000 live births.