Newborn jaundice is caused by high levels of bilirubin in the blood, which gives an infant's skin and eyeballs a yellowish tinge.

Bilirubin is a byproduct of the normal breakdown of red blood cells. The liver processes bilirubin so that it can be excreted by the body as waste. At birth, a baby's liver is still developing its ability to process bilirubin. Therefore, bilrubin levels are a little high at birth and jaundice is present to some degree in almost all newborns. This form of jaundice usually appears between the 2nd and 5th days of life and clears by 2 weeks. It usually causes no problems.

Breastfeeding jaundice is seen in 5-10% of newborns. This may occur when breast-fed babies do not take in enough breast milk and rarely requires treatment. Sometimes, however, breastfeeding does need to be interrupted and bottle-feeding substituted for a brief period of time to clear the jaundice.

Jaundice in a newborn is rarely caused by a serious illness. However, possible disorders that can cause jaundice in a baby include:

• biliary atresia
• ABO incompatibility (similar to a transfusion reaction, caused when fetal and maternal blood mingle before birth)
• Rh incompatibility (Anti-Rh antibodies)
• galactosemia (see galactosemia screen)
• cephalohematoma
• polycythemia
• glucose-6-phosphate dehydrogenase deficiency
• infections, including urinary tract infection and sepsis
• congenital cytomegalovirus (CMV) infection
• congenital toxoplasmosis
• congenital syphilis
• congenital herpes
• congenital rubella
• congenital hypothyroidism
• late pregnancy administration of sulfa drugs to the mother
• Crigler-Najjar syndrome
• spherocytosis (congenital hemolytic anemia)
• cystic fibrosis
• pyruvate kinase deficiency
• thalassemia
• Gilbert's syndrome
• Lucey-Driscol syndrome
• Gaucher's disease
• Niemann-Pick disease

• yellow color of the skin
• poor feeding (may be present)
• lethargy (may be present)

• elevated blood serum bilirubin level

Treatment is usually not necessary. Keep the baby well-hydrated with breast milk or formula. Encourage frequent bowel movements by feeding frequently. This is because bilirubin is carried out of the body by the intestines in the stools. (Bilirubin is what gives stool their brown color).

Sometimes artificial lights are used on infants whose levels are very high, or in premature infants. These lights work by helping to break down bilirubin in the skin. The infant is placed naked under artificial light in a protected isolette to maintain constant temperature. The eyes are protected from the light.

In the most severe cases of jaundice, an exchange transfusion is required. In this procedure, the baby's blood is replaced with fresh blood. Recently, promising studies have shown that treating severely jaundiced babies with intravenous immunoglobulin is very effective at reducing the bilirubin levels to safe ranges.

The jaundice usually resolves without treatment within 1 to 2 weeks.

Rare, but serious, complications from high bilirubin levels include:

• Kernicterus -- brain damage from very high bilirubin levels
• Deafness
• Cerebral palsy

Jaundice is an emergency if the baby has a fever, has become listless, or is not feeding well. Jaundice is dangerous in small, sick, and particularly acidotic newborns.

Jaundice is generally NOT dangerous in term, large newborns. Call the infant's health care provider if jaundice is severe (the skin is bright yellow), if jaundice lasts longer than 1 or 2 weeks, or if other symptoms develop. Also call the doctor if the hands and feet, particularly palms and soles, are yellow.

In newborns, some degree of jaundice is normal and probably not preventable. Prevention of disease-related jaundice is related to the specific disease.

Since babies are now sent home from the hospital quickly or are often born in settings like birthing centers, it is important for parents to be on the lookout for jaundice in their infants in the first few weeks of life.