Bilirubin



Bilirubin is a by-product of the breakdown of red bloods which normally circulate in the bloodstream for about four months until they literally wear out. ‘The liver processes and excretes bilirubin. If the liver is diseased, in hepatitis, or immature, as in newborns, the level of bilirubin in the bloodstream may become high enough to cause a yellow-orange discoloration of the skin, known as jaundice.

Before birth a baby’s bilirubin is largely managed through the mother’s circulation. After birth it takes a newborn’s liver a few days to take over this process, so the level of bilirubin in the baby’s bloodstream will innate by a modest amount. If a significant backlog forms, the baby’s skin will take on a yellow-orange hue, beginning with the head and gradually spreading towards the legs. Whether or not jaundice is significant will depend upon several factors, including the actual level of bilirubin, how soon and how fast it has risen, the suspected cause, and whether the baby is full-term or pre-nature. In some instances, extremely high bilirubin reels can damage the central nervous system, especially in the premature infant. If you notice your new baby’s skin color changing to bright yellow-orange, contact your baby’s doctor.



If there is any concern, the baby’s physician will order food tests to check the bilirubin level, and if needed, other studies will be done to look for underlying causes. Sometimes high levels of bilirubin result from a difference between a mother’s blood type and that of her new-born. For example, if the mother’s blood type is 0 and the baby’s is A or B, some anti-A or anti-B antibodies from the mother may cross the placenta into the baby’s circulation before birth. These antibodies can destroy any of the newborn’s red cells, leading to a high bilirubin level shortly after birth.

A more severe form of this process used to occur commonly in connection with a protein known as the Rh factor, which is either present on the surface of blood cells (making an Rh-positive or an Rh-negative). Whenever a mother with Rh-negative blood gave birth to an infant who was Rh-positive, the mother’s immune system could become sensitized to the Rh factor. If she had another pregnancy with an Rh-positive baby, her Rh antibodies would cross the placenta and destroy significant numbers of the new baby’s red cells. Babies born under these conditions were often jaundiced at birth and became quite ill, requiring immediate transfusions of antibody-free blood. Today Rh incompatibility problems are avoided by giving Rh-negative mothers a shot (called RhoGam) that prevents her immune system from developing Rh antibodies. In most cases, a newborn’s jaundice is the by-product of normal physiological processes and is not caused by an Rh or blood type incompatibility or other problems (such as infection). This so-called physiologic jaundice will eventually resolve on its own within 10 to 14 days. In some situations (depending on various factors), the baby’s doctor will recommend one or more of the following measures to help lower a bilirubin level that has become significantly elevated:



  • Treat any underlying cause (such as an infection), if present.
  • Increase the baby’s fluid intake by feeding her more often.
  • Expose the baby to indirect sunlight for periods of 20 to 30 minutes – dressed only in a diaper in sunlit room where the sun does not shine directly on her sensitive skin. Since indirect sunlight has only a modest effect on clearing bilirubin, don’t use this approach unless you are sure that your baby won’t become too hot or too cold.
  • Sometimes an enzyme found in the mother’s milk interferes to a modest degree with the clearing of bilirubin. Your physician may ask you to stop breast feeding for a short time and use formula until the problem improves, after which nursing can resume. In such a case, it is important that you continue to express milk to maintain your supply. This should not be an occasion to stop nursing altogether. Some healthy breast-fed infants will have a slight orange hue for weeks.
  • A treatment called phototherapy may be utilized if the bilirubin level needs to be treated. Under a physician’s direction, the baby lies under a special intense blue light while wearing eyeshades like a sunbather at the beach. In addition, or as an alter-native, a baby can lie on a thin plastic light source called a Bill Blanket. Whether carried out in a hospital or at home (using equipment provided by a home-health agency), phototherapy usually reduces bilirubin gradually within two or three days, if not sooner.

A newborn whose jaundice resolves and then re-appears should be checked by a physician, as should an older infant or child who appears jaundiced for the first time. Some older infants who are taking solids and regularly enjoy carrots and other yellow vegetables may actually develop a slight orange hue, which is harmless and has nothing to do with bilirubin. This does not cause the whites of the eyes to become yellow. A more obvious yellow coloration of skin (as well as the whites of the eyes) in a child may indicate that the liver is inflamed or (far less commonly) that the drainage of bile from the liver is obstructed.