Hyperbilirubinemia is an excess of bilirubin in the blood and is the main cause of jaundice. Bilirubin, is a normal part of the pigment released from the breakdown of "used" red blood cells and because bilirubin has a pigment or coloring, it causes a yellowing of the baby's skin, eyes, and other tissues. Normally, the liver filters bilirubin from the bloodstream and releases it into the intestinal tract. A newborn's immature liver often can't remove bilirubin quickly enough, causing an excess of bilirubin. Jaundice due to these normal newborn conditions is called physiologic jaundice, and it typically appears on the second or third day of life.
("Hyperbilirubinemia and Jaundice." - Online Medical Encyclopedia. University of Rochester, n.d. Web. 17 Nov. 2014.)
The first symptom is yellow appearance of the skin and the eyes. The infant’s skin may appear yellow as early as the 1st or 2nd day of life. The jaundice starts around the head and the face then progresses to the shoulders, arms and the rest of the body including the legs and feet. The appearance may become more yellow when the baby is 3 to 4 days old and then slowly gets better. This is called “physiologic” or normal neonatal jaundice. Most infants have this pattern so no testing is needed.
At times, the yellow appearance may occur earlier, last longer than 5-6 days or may be much more pronounced. A consultation with your health care provider is then needed to determine if testing is indicated.
Along with the skin becoming more yellow, the color of the baby’s urine can change from very light yellow or very dark brown. The color of the baby’s stool can vary from a yellow mustard color (normal) to light beige. These 2 color changes in the urine or the stool can indicate that the jaundice is due to different pigments. Although very rare in the first days of life, the presence of a very dark urine or light beige stool should be evaluated by a doctor immediately.
If the doctor is concerned about the severity of the jaundice, a blood test called a serum total bilirubin level is performed using a very small amount of blood.
A variety of conditions or diseases may present with an increase of the amount of bilirubin produced. Poor feeding due to decreased breast feeding or the amount of breast milk can contribute to the increase in bilirubin. The same can happen with formula if the infant is not able to drink a sufficient amount. Maternal diabetes, exposure to some medications such as sulfa drugs or being underweight can also cause an increased bilirubin level.
In some cases, the level of indirect bilirubin can go very high. Then, a neonatal specialist or blood specialist may be called in to help care for the newborn. Doctors are concerned if the bilirubin levels are more than 20-25 mg/dl (deciliter) and will start treatment to prevent the bilirubin from getting to this level. A level of indirect bilirubin at or above 20-25 mg/dl may cause irritation in some areas of the brain. This is called acute encephalopathy (inflammation of the brain). If the bilirubin remains very high, above 25 mg/dl, babies can be at risk for significant brain damage. This very rare condition is called kernicterus. Because of that risk, the doctor will start testing early for the bilirubin level and repeat the test often to identify the trend and start treatment rapidly.
In addition to blood work to look for infections, other testing may be performed. A specialist in liver disease in children, called a pediatric gastroenterologist, may be called in consultation to help sort out the diagnosis. Liver disease is diagnosed with additional blood tests; the specialist may order an ultrasound or other specialized testing. These may lead to a procedure called a liver biopsy, where a small sample of liver tissue is taken for examination under a microscope.(Neonatal Jaundice. (n.d.). Retrieved December 1, 2014, from http://patients.gi.org/topics/neonatal-jaundice/)
Treatments for jaundice include blood transfusion, phototherapy, and medication. Usually in normal physiologic neonatal jaundice, the process will be self-limiting and the baby does not need to be treated. With abnormally high bilirubin levels however, doctors may administer blood transfusion, an exchange of the infant's blood with normal blood. Phototherapy is implemented when bilirubin levels are slightly above normal. The infant is exposed to a fluorescent light called bililight, which causes a chemical change in the bilirubin under the skin and makes it easy to excrete through the liver.
Infants may also be given medication to reduce the level of bilirubin. The types of medication include phenobarbital which increases the conjugation and excretion of bilirubin, tin-protosoporphyrin and tin-mesoporphoryin, these two drugs block the production of bilirubin. (Retrieved December 1, 2014, from https://www.rose-hulman.edu/mathjournal/archives/ 2004/vol5-n1/paper5/v5n1-5pd.pdf)