Jaundice Health Article

Rare causes of severe neonatal jaundice

Jaundice can result from a congenital (present at birth) malformation of the liver, bile ducts, or gall bladder. Jaundice resulting from a congenital defect usually does not appear until the baby is at least ten days old. Biliary atresia—the underdevelopment, inflammation, or obstruction of the bile ducts that carry bile from the liver to the gall bladder and small intestine—causes bile to build up in the liver and forces the bilirubin into the blood. The cause of biliary atresia was as of 2004 unknown, and jaundice may not appear until the infant is two to six weeks old. Other symptoms of biliary atresia include:

• itching
• dark brown urine due to excess bilirubin excreted in the urine
• light-gray or chalky-colored stools from lack of bilirubin excreted by the intestines

Jaundice that develops or persists after the second week of life also can be due to the following:

• breast milk jaundice (prolonged jaundice resulting from breastfeeding) that occurs when a chemical in the mother's breast milk interferes with the infant liver's ability to process bilirubin
• liver malfunction or damaged liver cells
• an enzyme deficiency
• an abnormality of the red blood cells such as anemia
• blood hemorrhaging
• a blood infection (sepsis)
• a liver infection such as hepatitis virus
• toxoplasmosis, an infection caused by an animal parasite and transmitted to the fetus via an infected mother (House cats can be carriers of toxoplasmosis.)
• an infection anywhere in the body that impairs the efficiency of the liver, including neonatal herpes simplex or salmonella

Such infections may be congenital, having been passed from the mother to the fetus, or may occur after birth.

Other causes of jaundice

There are numerous other causes of neonatal and childhood jaundice, including the following:

• liver cell damage resulting from a variety of conditions such as a viral infection, an adverse drug reaction, or drugs or other chemicals that damage the liver (Jaundice can be a late symptom of hepatitis in an older baby or child.)
• hemolytic jaundice caused by hemolytic anemia, in which red blood cells are turned over faster than usual
• Hodgkin's disease in teenagers

Symptoms accompanying jaundice caused by liver cell damage may include:

• nausea
• vomiting
• abdominal pain
• swollen abdomen

When to call the doctor

A doctor should be consulted any time a child develops jaundice. Infants who are discharged from the hospital before bilirubin levels begin to rise, about three days after birth, should have their bilirubin level tested within a few days, particularly if they were preterm infants. Infants who become lethargic or reluctant to feed should be examined immediately, because symptoms can be signs of severe hyperbilirubinemia that can cause brain damage.

Diagnosis

Newborns are examined under good light for signs of jaundice. A simple blood test, with a few drops of blood taken from the infant's heel, measures bilirubin levels in the blood. The test may be repeated frequently in a jaundiced newborn to assure that bilirubin levels are dropping. An instrument called a bilirubinometer can be held against the baby's skin to assess the level of jaundice. The Minolta/Hill-Rom Air-Shields Transcutaneous Jaundice Meter accurately measures bilirubin levels by shining lights of different colors through the skin and measuring the reflection, eliminating the need for blood tests via heel pricks.

If there is reason to believe that the newborn is suffering from an abnormal jaundice, additional tests must be performed. These include:

• blood cell counts to detect anemia
• tests for blood clotting function
• tests for excess destruction of red blood cells
• blood tests to assess liver function
• a liver biopsy, in which liver cells are removed and examined under a microscope to look for liver disease
• urine and stool samples to check for signs of bacterial or viral infection

Breast milk jaundice due to a reaction with a breast milk component is suspected when the more common causes of jaundice have been ruled out.

Biliary atresia must be detected before two months of age to prevent further liver damage. Diagnoses of biliary atresia and other liver conditions are made by imaging techniques, including the following:

• ultrasound scanning, which uses sound waves to obtain images of the liver, gallbladder, and biliary tract (Abdominal ultrasound can distinguish between jaundice caused by biliary atresia and jaundice caused by liver malfunction.)
• magnetic resonance imaging (MRI) of the liver
• computed tomography (CT) or computed axial tomography (CAT) scans, which use a thin, rotating x-ray beam to obtain an image
• endoscopic retrograde cholangiopancreatography (ERCP), in which a radiopaque dye that is visible on x rays is inserted into the upper portion of the small intestine so that it flows back up the biliary tract
• liver scans using radioactive dyes