Bilirubin Count In Newborns

By Ashley | December 16, 2009

Bilirubin counts in newborns are one of the few aspects, which doctors look out for immediately after a child is born. This is because a high bilirubin count is a sign of jaundice and also of hemolysis occurring in uncontrolled proportions. In adults, jaundice is quite harmless as it is an excretory product. In fact, bilirubin is always present in the blood and is collected from the blood by the liver and excreted. A very crucial part of this cycle is stomach bacteria that are responsible for converting bilirubin into a form which causes most of it to be released in feces. In neonates, this does not occur rapidly enough because the intestinal flora has not yet developed. Therefore, a mild amount of elevated serum bilirubin does occur but it must be controlled. The biggest reason for concern is because in a neonate, the blood-brain barrier has not fully developed yet and bilirubin can pass right into the brain where it can accumulate in the brain tissue causing severe neurological damage. This does not occur in adults because the blood-brain barrier is well-developed.

Bilirubin is a natural byproduct that is created from the breakdown of red blood cells. When red blood cells die, they are broken apart into heme and globulin. The heme is then converted in the liver to biliverdin. After a further enzymatic transition, bilirubin is created and this is called indirect bilirubin that is not water soluble. It is then carried by serum albumin to another part of the liver to form conjugated bilirubin and excreted into the gall bladder where it forms bile. The bile is then used to neutralize stomach acids in chyme in the duodenum. After most of the chyme is absorbed the stomach bacteria breakdown the bilirubin in bile into two forms which can be excreted in urine and feces; thus, ending the cycle.

Neonatal jaundice is defined clinically when the serum levels are higher than 5mg/ L. It takes a level of 15 mg/dL for the skin color to start turning yellow. The treatment for this jaundice in the immediate case is blue light therapy because bilirubin is broken down into a water soluble isomer in the presence of light. Ensuring that this situation does not happen is a matter of breastfeeding. Through breastfeeding, the stomach is populated with the bacteria that are required to finish the last stage of bilirubin destruction.