A yellowish discoloration of a normal newborn baby's skin is known as physiologic jaundice or neonatal hyperbilirubinemia. (Bilirubin is the chemical in blood that causes jaundice.) The condition is quite common and usually harmless in healthy newborns, most of whom are no longer jaundiced by the end of the first week of life. In certain infants (particularly premature ones), however, jaundice is a more serious symptom that requires close medical attention.
Infants of Asian descent, Native Americans and Eskimos are more likely to develop hyperbilirubinemia—and to have extremely high levels of bilirubin—than Caucasian infants. The condition is less common in black infants than in whites or Asians.
WHAT CAUSES JAUNDICE?
Jaundice is a sign that the baby's blood contains an excessive amount of bilirubin, a substance released when old red blood cells break down. Normally, bilirubin is removed from the blood stream, processed in the liver, and passed from the body in the feces as part of a fluid called bile. In newborns, however, this process tends to be inefficient, partly because the liver is immature and partly because a large number of red blood cells are broken down soon after birth. Most of the time, the situation corrects itself over the first several days of life. If the baby is premature, however, bilirubin levels may reach very high levels in the blood, creating a dangerous situation in which the substance may be deposited in the brain and cause permanent damage.
HOW DOES JAUNDICE DEVELOP?
If a newborn baby's bilirubin level is higher than normal, the skin may take on a yellowish tinge. Jaundice usually appears first on the baby's face. It may then worsen, spreading to the chest, stomach and legs. The pediatrician will note the condition and treat it (usually by exposing the baby to fluorescent light) if necessary. This may be done in the hospital or at home using a biliblanket.
For reasons that are still unclear, breastfeeding sometimes triggers jaundice in newborns between two and four days after birth. This occurrence may be due in part to the limited amounts of fluid and calories babies get from nursing before the milk supply is established. It is more likely, though, that some component in breast milk interferes with the excretion of bilirubin.
IS MEDICAL ATTENTION NECESSARY?
Bilirubin levels normally drop and jaundice diappears in the first week of life. If the bilirubin level is very high or does not drop on its own, however, the pediatrician will take steps to decrease it.
HOW CAN THE PEDIATRICIAN TELL IF MY INFANT HAS JAUNDICE?
Pediatricians examine all newborns every day until they are discharged from the hospital. The examination is carried out while the baby is undressed and in a well-lighted area, so skin discoloration will be obvious. To detect jaundice in black and other dark-skinned infants, pediatricians compress the skin slightly, which reveals underlying yellowness.
If a newborn is jaundiced, the pediatrician will generally recommend a laboratory test to determine the level of bilirubin in your baby's blood. This is probably the most common test performed on newborns. If the bilirubin level is excessively high and remains high over several successive tests, the pediatrician will recommend treatment.
If you are taking your baby home from the hospital within 24 hours of birth, your nurse or doctor may show you how to watch for the development of jaundice in your baby's skin and eyes. A visiting nurse may come to your home to monitor the baby's bilirubin level.
WHAT TREATMENTS ARE AVAILABLE?
The most common treatment is phototherapy, in which the infant is placed under bright, fluorescent lights, which convert bilirubin to a form that is easily excreted. Phototherapy, which usually lasts only a day or two, is indicated if jaundice is severe or does not subside on its own.
The doctor may also suggest that you halt breastfeeding for 24 to 48 hours, another technique to help the baby's liver expel bilirubin. During this time, you should continue to pump your breast milk so that you can quickly re-establish nursing. If very high levels of bilirubin develop, particularly in premature infants, an exchange transfusion may be needed to remove the bilirubin from the baby's blood. Finally, the pediatrician may take blood tests to monitor the baby's bilirubin level and to determine if the jaundice is a symptom of another underlying disorder.
