Definition Jaundice is a yellowish discolouration of the skin and the whites of the eyes. It is caused by too much of a chemical called bilirubin in the blood.
What is going on in the body? The haemoglobin molecule in a red blood cell carries oxygen to all the cells in the body. Each haemoglobin molecule contains 4 molecules of iron. The body usually separates and recycles iron from haemoglobin molecules. Bilirubin is a normal chemical by-product of this recycling process. The body does not need bilirubin. Bilirubin travels through the blood to the liver. The liver converts it so that it can be removed in urine. When a child or adult has too much bilirubin in their blood, they become jaundiced.
It takes a few days for a newborn's liver to start processing bilirubin. It may take longer in infants who are born prematurely or who are breastfed. About 80% of premature infants and 60% of full-term infants will have some visible jaundice. This is a normal condition. It is not harmful and will usually go away without treatment.
There are two main causes for too much unprocessed bilirubin. One cause is that more bilirubin is being made than can be processed. The other cause is that the baby cannot get rid of the processed bilirubin.
Too high a level of bilirubin can occur:
when a baby's blood type is different from the mother's. For example, the mother has blood type O, and baby is A or B.
in cases of identical twins, sometimes one baby gets more blood than the other. This baby who gets more blood can develop jaundice after it is born.
when there is a swelling on a newborn's head. This is a collection of blood between the scalp and the skull from pressure on the head during the birthing process. As this blood is absorbed, excess bilirubin is provided.
when there are inherited defects of the red blood cell.
The inability to remove bilirubin can occur when:
babies who have certain blood infections cannot process bilirubin.
medications such as antibiotics interfere with the process.
a number of genetic disorders are present.
a blockage or cyst on the bile duct exists. Sometimes the bile duct system has not developed properly
babies are born with Down syndrome or thyroid problems.
babies are breast-fed.
Too much unprocessed bilirubin can cause complications. The unprocessed bilirubin can get into the brain where it causes permanent damage. It usually takes a fairly high level of unprocessed bilirubin to be toxic. High levels of processed bilirubin are not as toxic. However, high levels of processed bilirubin suggest the need for prompt attention.
What are the signs and symptoms of the condition? In the newborn, jaundice first becomes visible on the face. As levels of bilirubin go up, the jaundice will move from head-to-toe. By the time an infant is jaundiced all over, bilirubin levels should be measured. Just looking at the baby is not an accurate test. Colour can be influenced by many things, such as lighting or the colour of the walls.
Infants with higher levels of jaundice look more orange than yellow. The jaundice is more intense. Babies with higher bilirubin levels often are less active and do not feed well.
Jaundice does not cause fever. A jaundiced infant with fever needs to be checked promptly for infection.
What are the causes and risks of the condition? A baby born prematurely is more at risk for jaundice. Infection, not getting enough oxygen during birth, and some drugs may increase the risk.
What can be done to prevent the condition? Normal antenatal care and blood tests are available that measure bilirubin levels. The amniotic fluid can be checked. If there are problems, the foetus might need a blood transfusion. There are also drugs the mother can take to help prevent the condition.
How is the condition diagnosed? Blood tests are done to find out how much bilirubin is present and why. The parents are asked if there might be any inherited causes. The health of the mother and baby during the pregnancy may give answers. The baby is examined for infection, anaemia, liver disease, and other problems. If the jaundice persists for several weeks, an ultrasound examination of the liver and bile duct system might be needed and a sample of the infant's liver may be required for a biopsy.
What are the long-term effects of the condition? Infants who suffer brain damage from very high levels of bilirubin may develop severe symptoms. These include a high-pitched cry, body stiffness, and seizures. Some of these infants die. Those who survive will develop symptoms as they age. By age 3, they will develop a type of cerebral palsy, seizures, mental deficiency, hearing loss, and speech and eye muscle disorders.
What are the treatments for the condition? Most infants with newborn jaundice can be treated with special lights used for phototherapy. Unprocessed bilirubin in the skin can be processed if it is exposed to light. Fluorescent lights are used. Focused halogen lights and fibre-optic, wrap-around blankets have also been used. With training and supervision, these treatments can be done at home.
Some types of jaundice cannot be treated with phototherapy. An exchange transfusion may be needed. A catheter is inserted into the belly button, or umbilicus. A small amount of the baby's blood is removed. It is immediately replaced with donor blood. This is repeated until enough has been exchanged. The bilirubin level is measured at intervals. This procedure has risks. It should be done by trained staff with proper equipment.
Breast milk jaundice is harmless and no treatment is necessary.
What are the side effects of the treatments? Phototherapy can be harmful to the eyes. Eye protection must be used. Phototherapy has no other known risks.
Exchange transfusion can cause changes to the acid levels in body fluids, called metabolic acidosis, low blood sugar or calcium levels, changes in heart rate or heartbeat, and inadequate breathing. The baby may need resuscitation. Clotting or infection of the umbilical vein could result in liver complications. Any blood transfusion carries with it the risk of introducing infections. These include HIV, hepatitis B, hepatitis C or cytomegalovirus infection.
How is the condition monitored? Infants who have transfusions must be watched carefully. They can develop anaemia, which is a low red blood cell count. The common post-birth and breast-milk jaundice does not come back once it resolves. No long-term monitoring is needed for those conditions. Inherited diseases causing jaundice and conditions requiring surgery need long-term follow-up care.
Author: John Wegmann, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
