The normal baby is born with a healthy pink coloured skin and very clear whites of the eyes. Jaundice refers to a distinctive yellowish discolouration of the skin and the whites or sclera of the eyes. Although jaundice can occur at any age due to a variety of different diseases, it is particularly important and significant in the immediate newborn period and early life.

Jaundice is due to the accumulation of a substance known as bilirubin. It is a breakdown product of haemoglobin in the blood which is the all important oxygen carrying vehicle present in the red blood cells. All normal red cells of blood have a life span of approximately 120 days and there is a constant and dynamic breakdown of the red cells in the human body. New red cells, containing brand new haemoglobin, are produced to counteract this breakdown of red cells. This process redresses the balance and the blood haemoglobin concentration is maintained at a constant normal level.

When the haemoglobin is broken down, it is converted to the substance known as bilirubin which is a breakdown product. Normally it is transported in the blood to the liver which deals with it and excretes it in bile. For a variety of reasons, this process may be hampered and then an abnormal accumulation of bilirubin in the blood leads to jaundice. Bilirubin has a tremendous affinity to elastic tissue in the body and it gets deposited in areas where there is an abundance of such tissues. The skin and the whites of the eye contain large amounts of elastic tissue and thus bilirubin has a tendency to get deposited in these organs. Bilirubin is yellow in colour and that is the reason for the yellowish discolouration of the skin and the sclera of the eye in jaundice.

The baby in the womb has to extract oxygen from the relatively low levels found in the mother’s blood. As a compensatory mechanism the foetus is found to have a considerably higher level of haemoglobin. It is a compensatory mechanism induced by nature. After birth, when the baby breathes normal air, the blood can increase the oxygen content markedly. Thus the need for a higher haemoglobin level is removed and the baby’s body breaks down the excess amounts of haemoglobin. During this process of natural readjustment, a larger than normal amount of bilirubin is produced and it sometimes overwhelms the capacity of the liver to deal with this excessive load. The higher level of bilirubin in the blood then leads to jaundice of the newborn. Jaundice usually appears first on the face, then on the chest and abdomen, and, finally on the legs.

Jaundice is not a disease in the strictest sense of the word. It is just a sign of a problem. Normal healthy newborn babies, especially premature babies, often develop mild jaundice, called "physiologic" or "normal" jaundice. This manifestation comes on a few days after birth, usually beyond the third day. Premature babies are more prone to develop jaundice as their livers are also immature and are not able to deal with the increased loads of bilirubin. Most of the time this goes away by itself, as the baby’s liver starts to develop and function more efficiently. In many instances, especially in term babies, this does not need any special treatment.

However, jaundice appearing on the first two days, especially if it comes on during the first 24 hours, is generally abnormal and there is usually a sinister cause for it. The commonest reason for this is an incompatibility of the blood groups of the mother and the baby. There can be incompatibility of the Rhesus (Rh) group where the mother is Rh negative and the baby is Rh positive. In other instances there can be the more widely known ABO type of incompatibility. In all these cases the mother produces antibodies against the baby’s blood constituents. Such antibodies cross the placenta, get into the baby’s blood stream even before birth and destroy the baby’s red blood cells leading to jaundice. It is known as haemolytic disease of the newborn. The problem with this type of jaundice is that the accumulated bilirubin, above a certain level, could cross into the newborn baby’s brain. This process could lead to cause a form of brain damage. Once bound to cells of the brain, this bilirubin cannot be easily removed and the baby develops permanent brain impairment. There is nothing on earth that could reverse this damage. It is absolutely essential to prevent the bilirubin levels rising beyond dangerous limits at all cost. In the case of Rh incompatibility, the risks to the baby increases with successive pregnancies as the mother’s antibody levels continue to rise with each Rh incompatible pregnancy. However, this could be prevented by injecting a special drug known as Rhogam to the mother within 24 hours of the birth of the baby which will prevent her developing antibodies which could give trouble in succeeding pregnancies.

In these abnormal situations, the baby’s blood level of bilirubin is estimated, sometimes at frequent intervals, and appropriate action should be instituted without any unnecessary delay. If the level is rising rapidly, active measures are undertaken even before the bilirubin rises to dangerous levels. The simplest way of reducing the bilirubin levels in the blood is to expose the body of the baby to light of a special wave length. This is known as phototherapy using blue light. This procedure converts the bilirubin to a form which is less toxic to the brain and is more easily dealt with by the body. However, if the situation is considered to be more urgent, the treatment of choice is to partially remove some of the baby’s blood and replace it with normal blood with a normal bilirubin level. This is known as an exchange transfusion. This procedure can dramatically reduce the blood levels of bilirubin very rapidly. It has to be done quite slowly and it usually takes about 2 to 3 hours for this procedure. In experienced hands it is quite a safe procedure.

In another situation, a baby in the immediate newborn period develops significant jaundice due to a germ that has spread right throughout the body. This is known as the condition of septicemia. Such infections need to be vigorously treated with antibiotics and all ancillary measures taken to try and reduce the jaundice as well. A special type of infection that specifically affects the liver of the newborn baby too can lead to jaundice. Several viruses, especially those contracted by the baby while in the womb, are known to do this. This condition is referred to as neonatal hepatitis syndrome. This leads to a prolonged state of jaundice which lasts for weeks and months. This too has some complications, mainly in the form of long lasting damage to the liver.

Jaundice of the newborn could also be due to a plethora of surgical causes. One of the more important problems in this group is where the baby is born with an obstruction to the drainage of bile via the bile ducts, from the liver to the intestine. This condition is known as biliary atresia. The obstruction leads to bilirubin and other waste products being thrown back into the blood stream leading to jaundice. The liver normally converts the brain-toxic type of bilirubin to the less harmful type of bilirubin that is excreted in the bile. Thus in this type of jaundice there is very little risk to the brain but the back pressure of the obstructed bile ducts cause damage to the liver leading ultimately to cirrhosis in untreated cases. The damage to the liver becomes irreversible after about two months of age and as such when this condition is suspected, urgent diagnostic measures are institutes and treatment contemplated within about six weeks of birth. The definitive treatment needs surgery and it is a rather tricky operation. The operation is named after the Japanese surgeon Kasai who pioneered this treatment. Unfortunately, the success rate of the operation is also not invariable and the longer the operation is delayed, poorer will be the outcome.

The all important message regarding jaundice in the newborn baby is that if it is noticed, the baby needs to be seen by a qualified doctor as soon as possible. Only such a person will be in a position to properly assess the condition, do the necessary tests and decide on the appropriate course of action. In many instances, a lot could be done for these babies. Even in cases where the jaundice is due to a relatively simple cause, it is only a trained doctor who would be able to reassure the parents in this regard. All the treatable causes of jaundice, when adequately dealt with, will prevent long term problems and after recovery the baby will be quite normal. This is particularly true for haemolytic disease of the newborn. Before the advent of exchange transfusions, a lot of these babies were left with intractable permanent disabilities due to brain damage. No doctor would now allow bilirubin levels to rise to such dangerous levels without instituting urgent measures to deal with the problem.