So just what is jaundice and what causes it?  Physiological (normal functioning) jaundice is a normal state that occurs in half of all term babies.  The destruction of red blood cells exceeds their production, placing an increased bilirubin (yellow breakdown product excreted in bile and urine) load on the baby’s immature liver which produces the yellow discolouration known as jaundice.

Jaundice usually peaks on day 3 after birth, usually resolving by one week of age.  The newborn with jaundice is usually well but may not be as alert.  Effective, frequent breastfeeding (or artificial feeding), assists the baby to break down the bilirubin which is what causes the yellow jaundice colour.  Placing baby by a window but out of direct sunlight also helps to break down the bilirubin which will be converted into a water soluble state and it is then excreted in the urine and stools.  It is very important that baby stays alert and is not lethargic if jaundiced.  If your baby is jaundiced and lethargic, seek medical advice immediately as jaundice can be a serious condition.


The use of blue lights to enhance bilirubin excretion by photochemically converting bilirubin into a water soluble substance which can be excreted by the kidneys.  The use of phootherapy is decided upon by a serum bilirubin (SBR) blood test, taken from the baby when a high level of jaundice is expected by a marked yellow discolouration or by a high biliscan

A baby who is jaundiced at less than 24 hours of age will always need further investigating.  Most bilirubin is produced by a breakdown of haemoglobin (iron containing compound found in the red blood cells) within the spleen.  Jaundice occurs as a consequence of the changeover from intrauterine (in the uterus) to extrauterine (outside the uterus/birth) life.  Newborns have many more red bood cells than the required adult level.  As the excess red blood cells break down, there is an increased bilirubin load on the baby’s immature liver.  Extra red blood cells are necessary in utero to increase the oxygen carrying capacity of the blood.

After birth, the high number of red blood cells is no longer required, so the excess is broken down which may then result in a physiological jaundice.

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