During pregnancy, the placenta removes bilirubin. When the baby is born, the baby’s liver must take over this function. There are several causes of hyperbilirubinemia and jaundice, including the following:
- Physiologic jaundice. Physiologic jaundice occurs as a “normal” response to the baby’s limited ability to excrete bilirubin in the first days of life.
- Breast milk jaundice. A very small number of breastfed babies develop jaundice when they are 2 to 12 weeks old. Babies who are born early may have trouble breastfeeding at first and may also develop jaundice.
- Jaundice from hemolysis. Jaundice may occur with the breakdown of red blood cells due to hemolytic disease of the newborn (Rh disease), or from having too many red blood cells that break down naturally and release bilirubin.
- Jaundice related to inadequate liver function. Jaundice may be related to inadequate liver function due to infection or other factors. In this condition, the direct bilirubin is increased.
About 60 percent of term newborns and 80 percent of premature babies develop jaundice. Infants of diabetic mothers and of mothers with Rh disease are more likely to develop hyperbilirubinemia and jaundice.
Although low levels of bilirubin are not usually a concern, large amounts can circulate to tissues in the brain and may cause seizures and brain damage. This is a condition called kernicterus.
The following are the most common symptoms of hyperbilirubinemia:
- Yellow coloring of the baby’s skin and eyes (usually beginning on the face and moving down the body)
- Poor feeding or lethargy.
The symptoms of hyperbilirubinemia may look like other conditions or medical problems. Always consult your baby’s doctor for a diagnosis.
The timing of the appearance of jaundice helps with the diagnosis. Jaundice appearing in the first 24 hours is quite serious and usually requires immediate treatment. When jaundice appears on the second or third day, it is usually “physiologic.” However, it can be a more serious type of jaundice. When jaundice appears toward the end of the first week, it may be due to an infection. Later appearance of jaundice, in the second week, is often related to breast milk feedings, but may have other serious causes, such as biliary atresia.
Diagnostic tests for hyperbilirubinemia may include:
- Direct and indirect bilirubin levels. These reflect whether the bilirubin is bound with other substances by the liver so that it can be excreted (direct), or is circulating in the blood circulation (indirect).
- Red blood cell counts
- Blood type and testing for Rh incompatibility (Coomb’s test).
Treatment depends on many factors, including the cause of the hyperbilirubinemia and the level of bilirubin. The goal is to keep the level of bilirubin from increasing to dangerous levels. Treatment may include:
- Phototherapy. Since bilirubin absorbs light, jaundice and increased bilirubin levels usually decrease when the baby is exposed to special blue spectrum lights. Phototherapy may take several hours to begin working and it is used throughout the day and night. Different techniques may be used to allow all of the skin to be exposed to the light. The baby’s eyes must be protected and the temperature monitored during phototherapy. Blood levels of bilirubin are checked to monitor if the phototherapy is working.
- Fiberoptic blanket. Another form of phototherapy is a fiberoptic blanket placed under the baby. This may be used alone or in combination with regular phototherapy.
- Exchange transfusion to replace the blood that has a high bilirubin level with fresh blood that has a normal bilirubin level. Exchange transfusion helps increase the red blood cell count and lower the levels of bilirubin. An exchange transfusion is done by alternating giving and withdrawing blood in small amounts through a vein or artery. Exchange transfusions may need to be repeated if the bilirubin levels remain high.
- Adequate hydration with breastfeeding or pumped breast milk. The American Academy of Pediatrics recommends that, if possible, breastfeeding be continued. Breastfed babies receiving phototherapy who are dehydrated or have excessive weight loss can have supplementation with expressed breast milk or formula.
- Treating any underlying cause of hyperbilirubinemia, such as infection.
While hyperbilirubinemia cannot be totally prevented, early recognition and treatment are important in preventing bilirubin levels from rising to dangerous levels, and thus preventing kernicterus.