Congenital liver defects are liver disorders that are present at birth. They are rare. These liver disorders usually block the bile ducts. This affects the flow of bile. Bile is a fluid made in the liver. It helps with digestion. The bile ducts take bile from the liver and bring it to the gallbladder to be stored. Then they carry bile to the small intestine for digestion.

Healthcare providers don't know the exact cause of congenital liver defects. Most likely they are caused by something that occurred as the unborn baby was developing or around the time of birth. This might happen because of one or more of the following:

A viral or bacterial infection after birth
An immune system problem, such as when the immune system attacks the liver or bile ducts for unknown reasons
A genetic mutation. This is a long-lasting change in a gene’s structure.
A problem during liver and bile duct development in the fetus
Contact with toxic substances