newborn jaundice, neonatal jaundice

Majority of newborn babies develop some jaundice on the second or third day of life. It gradually increases till about the fifth day and then gradually deceases.

This newborn jaundice usually does not need any treatment. But in some babies the jaundice can increase above safe limits requiring phototherapy (keeping the baby under blue tube lights).

Blue light converts bilirubin (the substance that is responsible for yellow coloration of eyes and skin) into more soluble substances, which are easily excreted. This is called physiological jaundice and is normal.

It is the only period in human life when jaundice is considered as “normal”. Any jaundice during the first 24 hours is always abnormal and needs investigations.

Factors contributing to physiological jaundice: Multiple factors contribute to the development of jaundice in the newborn baby. Jaundice (yellowish discoloration of skin) is due to the abnormally high level in blood of a pigment called bilirubin.

Bilirubin is derived from the breakdown of hemoglobin, which is present inside the red blood cells of our blood. Hemoglobin is responsible for carrying oxygen to all the cells in the body.

The red blood cells of a newborn are somewhat different from those of adults. They have a shorter life span and die earlier, releasing bilirubin into the blood. The newborn baby also has higher concentration of hemoglobin compared to adults.

Bilirubin is metabolized in the liver and then excreted through bile, which flows into the small intestine. The liver of a newborn is not fully mature and cannot handle all the bilirubin quickly. All these factors result is jaundice.

Cephalhematoma (bleeding into the scalp which is common in newborn babies) can aggravate physiological jaundice.

Other conditions which can aggravate physiological jaundice are birth asphyxia (baby not crying immediately after birth), congenital hypothyroidism (deficiency of thyroid hormone in the newborn baby) and some drugs (gentamycin, kanamycin etc). In a premature baby jaundice tends to be more severe due to greater immaturity of the liver.

Breast milk jaundice: Exclusive breast feeding may cause prolonged physiological jaundice in some newborn babies. Breast milk contains a substance which inhibits binding of bilirubin. But this condition is benign and subsides spontaneously. There is no need to stop breast feeding.

Jaundice in newborn is not always normal. Many diseases can cause jaundice. Abnormal jaundice is of two types-unconjugated (indirect) and conjugated (direct). But normal (physiological) jaundice is always unconjugated.

After being released from the red blood cells bilirubin remains free for some time (unconjugated). It is taken up by liver and bound to a protein (conjugated) so that it can be excreted in the bile.

Increased production of bilirubin: Occasionally there may be abnormal destruction of red blood cells-a condition known as hemolytic anemia. Several diseases can lead to hemolytic anemia.

Deficiencies of certain enzymes (glucose 6 phosphate dehydrogenase) and defects in the covering of the red blood cell (spherocytosis), or antibodies against the red blood cells of baby produced in the mother’s body due to incompatibility between the blood groups of mother and baby.

The incompatibility can be due either to Rh group or ABO groups. The problem of Rh incompatibility is seen when the mother is Rh negative and the baby Rh positive. Usually the first baby does not have any problem as the mother gets sensitized at the time of delivery.

That is why the mother is given an injection to prevent sensitization. The injection contains antibodies to the Rh antigen containing red blood cells of the baby. The antibodies destroy the cells containing the antigen so that the mother does not become sensitized to it.

ABO incompatibility arises when the mother’s group is O and the baby’s is either A or B. Sometimes the destruction of baby’s red blood cells can be so severe (either due to Rh or ABO incompatibility) that we need to replace baby’s blood with some other compatible blood- a procedure known as exchange transfusion.

Diseases of the liver: Deficiency of some enzymes can cause jaundice. Crigler-Najjar syndrome is due to deficiency of an enzyme which is responsible for binding bilirubin. This is a hereditary condition.

Neonatal hepatitis is a condition that can cause chronic liver disease with jaundice. It may be due to viral, parasitic or bacterial infections but in many babies no cause can be identified.

Liver biopsy is required to establish the diagnosis. Some babies affected by this condition develop cirrhosis in which there is scarring of liver.

Obstruction to the flow of bile: There is a condition called biliary atresia in which the tubes, which carry bile from the liver into the intestine are not developed at all. The prognosis for this condition is not very good. An operation called Kasai’s procedure is performed to connect the liver to the intestine.

SBI!

Management of newborn jaundice