General information, facts and myths!
Original Post on 30 Nov 2007
What is Jaundice?
Jaundice is the appearance of yellowish discolouration on the hands, feet, eyes and other body surfaces because of accumulation of the yellow pigment bilirubin. The degree of yellowness depends on the amount of bilirubin that has been accumulated.
Why do newborn babies become jaundiced?
There are many reasons why a baby may become jaundiced. The most common form of jaundice is called physiological jaundice because it results from a natural process.
Briefly:
Inside the womb the unborn baby is dependent on its mother for all the nutrients, even oxygen. The mothers blood which reaches the placenta carries oxygen combined with the maternal haemoglobin (a form called adult haemoglobin). Inside the placenta, across the placental barrier, the baby has to extract the oxygen from the maternal blood by literally snatching it away from the maternal haemoglobin. For this to happen, the baby has a special form of haemoglobin called fetal haemoglobin; one that has a much stronger affinity (pulling power) for oxygen than the adult haemoglobin. Through out the fetal period, the baby continues to extract oxygen from maternal blood in this way.
Once the baby is born, it can then get its oxygen directly from the air via the lungs. The oxygen in air is free, not combined with other compounds from which it has to be snatched from. Thus physiologically there is no need for a haemoglobin with a very high oxygen affinity after birth when free oxygen is available.
Because of this change in the oxygen supply, the haemoglobin in the baby’s blood begins to change to the adult form. To give way for the adult haemoglobin, the fetal haemoglobin is broken down. One of the bi-products of this breakdown process is a yellow pigment called bilirubin.
The bilirubin so produced is cleared from the blood by the liver. If the rate of production of bilirubin is higher than the rate at which the liver is able to clear it, the bilirubin level builds up and leads to jaundice. In premature babies this is more evident as their livers are not mature enough to handle high bilirubin loads.
Jaundice may also be caused by other conditions and disease processes. G6PD deficiency, the deficiency of a surface protective enzyme for red blood cells, is common in the Maldives and is a cause of jaundice. Blood group incompatibilities between baby and mother could also cause jaundice. Rhesus (Rh) incompatibility, where an Rh +ve baby born to a sensitised Rh -ve mother, leads to one of the most severe forms of jaundice.
Other causes of jaundice include intestinal and hepatic malformations, blood disorders, severe infections including congenital infections and metabolic disorders. These are all relatively rare.
MISCONCEPTION: Baby or mother wearing yellow clothing or mother eating yellow food causes jaundice! This is not correct! Some clinicians and healthcare workers may remove yellow clothing worn by a jaundiced baby to assess the degree of jaundice (assessing jaundice in a well lit room against a non-yellow background helps the human eye in detecting the severity of jaundice by increasing the contrast). There is no medical reason to advice against using yellow clothing for babies!
At what age do babies become jaundiced?
All babies are expected to have a transient rise in serum bilirubin. But only a portion of them would have clinically visible and significant jaundice.
By about the 2nd or 3rd day most babies maybe noted to have a mild yellowish stain in their sclera (the while part of the eye). The colour may slightly increase in some and persist without further increase for about a week or so.
In babies who have severe forms of jaundice, the yellowness may be visible even on the first day! It progressively increases and could cause deep yellow staining of the eyes, body, hands and feet.
What happens to a baby if jaundice is very severe?
Mild jaundice clears on its own and has no effect on the child. However, severe jaundice could potentially cause very significant damage to the child’s developing brain.
Deposition of the bilirubin inside the brain can cause a condition called Kernicterus in which significant, irreversible damage occurs to the brain. The affect could have varying severity of intellectual disability, developmental disability and neurological sequelae including seizures.
Current medical practices are aimed at reducing the severity of jaundice by assisting the body in removing the accumulated bilirubin and in severe cases removing the bilirubin by exchange transfusions.
What is the treatment for jaundice?
When a baby is noted to have jaundice, its cause and severity is assessed. The severity may be assessed visually by an experienced clinician or as more commonly done; measured either by blood tests or transcutaneous monitors. If significant jaundice is detected, in addition to instituting treatment, investigations are carried out to understand the cause of jaundice. If a treatable cause is found, then it is addressed.
The very mild jaundice need no treatment. It gradually clears on its own. In cases of significant jaundice the most commonly used 1st line of treatment is phototherapy.
Phototharapy is given by placing the baby unclothed (eyes covered for protection) under a special “blue” light. This light is different from the light that comes from ordinary household tube lights. It is of a specific wavelength (~480nm; so the different colour).
When this special light touches the skin it causes a chemical structural change in the bilirubin present under that area of the skin. The change in structure makes it more soluble in water and thus helps in the excretion of the bilirubin from the body.
MISCONCEPTION: Common household tube lights help reduce jaundice! This is false! The tube lights placed inside the hospital phototherapy units are different from common household tube lights. The common household tube lights do not emit significant amounts of “the blue wavelength” light required for phototherapy. Doctors or other healthcare workers who advice parents to keep the “white” household tube lights “on” at all times in the baby’s room to help minimise jaundice are giving parents a false sense of security. This form of “light therapy” does not help, it could do harm because it could potentially delay the use of the correct therapy.
Even the correct phototherapy light does not provide significant benefit from a distance. The best evidence is that the phototherapy lights should be approximately 30cm from the baby’s skin. The light should also fall on exposed skin, the larger the surface area exposed the better.
Therefore, keeping a fully clothed baby in a room with all ceiling and wall light fixtures turned on sounds a bit silly!
For the very severe degrees of jaundice, intensive phtotherapy is sometimes augmented by an exchange transfusion. During an exchange transfusion the high bilirubin loaded baby’s blood is exchanged with a donors blood low in bilirubin. The process removes excess bilirubin and the type of blood used could minimise the risk of its re-accumulation as well.
Intravenous immunoglobulins are increasingly being used in some centers for Rh incompatibility associated jaundice, this is not possible in Male’ as the drug is not available.
Medications such as phenobarbitone, an anticonvulsant, used to be prescribed for jaundice in the past. It is no longer commonly used or recommended.
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