As the red blood cells expire, a substance called bilirubin gets formed. Though it has the role of an antioxidant, high levels of it can lead to the body turning yellow, indicating jaundice. The compound bilirubin is the waste product of dead RBCs that are excreted through the liver, and high levels of it can be an indicator of liver malfunction. People with chronic liver disease have elevated bilirubin levels, also referred to as hyperbilirubinemia.
What is hyperbilirubinemia?
Hyperbilirubinemia is commonly seen in infants, which can cause neonatal jaundice. Dr Sandeep R, consultant, neonatology and pediatrics, Rainbow Children’s Hospital, Bangalore, explains, “We have a substance in our body called bilirubin, which is produced once the red blood cells (RBCs) die. In a newborn, the main problem is that the lifespan of RBCs is very short. It ranges between 60 and 90 days, compared to an adult whose RBC lifespan is 120 days. For the body weight of a neonate, the blood volume is a little more and the liver capacity is also very less (as they are not mature), causing neonatal jaundice.”
He adds that a bilirubin level of less than 1 mg/dL is normal for adults. If it exceeds 2 mg/dL, their eyes turn yellow. Dr Lathiesh Kumar, lead, neonatology and consultant, pediatrics and neonatology, Aster Women and Children Hospital, Whitefield, Bangalore, says, “Neonatal refers to an age of less than 28 days. So, when jaundice occurs in the first 28 days of life, we call it hyperbilirubinemia.”
Role of bilirubin
Bilirubin plays the role of an antioxidant. Babies inside the womb are exposed to very little oxygen. Dr Sandeep says, “As soon as they come out, the oxygen volume in their blood suddenly goes up, which can be toxic. To prevent this, there are a lot of antioxidants, and one of them is bilirubin. After the baby starts maturing, they adapt to the high oxygen levels, and the bilirubin levels start coming down.”
Almost every baby has jaundice, say experts. However, whether it should be treated immediately depends on the risk factors and bilirubin value. In most cases, babies recover from neonatal jaundice or hyperbilirubinemia after the sixth day. As the baby starts feeding, the liver also starts maturing postnatally, and the bilirubin levels start coming down.
Types of neonatal jaundice
Dr Sandeep shares that there’s direct and indirect jaundice. “In direct jaundice, when the bilirubin goes to the liver, it gets conjugated. So, there is an additional molecule added to the bilirubin before it gets excreted. In indirect jaundice, there’s a problem with the liver after decreased conjugation, due to which the bilirubin does not escape the body and comes back into the blood,” he says.
Two types of jaundice exist for neonates as well: breastfeeding jaundice and breastmilk jaundice. Dr Sandeep says, “In the initial few days, milk secretion in the mother is very low. Hence, the baby passes less stool, causing bilirubin to get reabsorbed into the blood. This is called breastfeeding jaundice. The treatment for this is feeding the baby properly. If the baby feeds well, they put on weight and start passing more stool, which takes care of the jaundice.”
In addition, some breast-fed babies can also develop breast milk jaundice, which persists even beyond two weeks. It is caused by some genetic mutations and is associated with a component called alpha-pregnenolone present in breast milk. It does not occur in most babies and is not very dangerous. It does not require any treatment unless the bilirubin levels rise excessively, more than 20 mg/dL, says Dr Sandeep.
Hyperbilirubinemia: Diagnosis, risk factors and complications
Dr Kumar says a blood test called serum bilirubin is done to check the bilirubin levels. The risk of hyperbilirubinemia for a person is then assessed using a chart called the Bhutani nomogram. In babies, other risk factors like birth weight, gestational age and Rh (a protein found in RBCs) incompatibility between the mother and the baby are also assessed. Postnatal weight loss and issues with feeding can also add to the risk of jaundice. After assessing these risk factors, the course of treatment is decided.
The blood test is also done at 48 hours when the mothers and their babies are usually discharged. The parents are asked to look out for signs of jaundice, like the eyes turning yellow. Experts also look at the stool color. “If the stool is white or clay-colored instead of yellow, it means there is a problem in the liver,” says Dr Sandeep.
The goal is to ensure that the levels of bilirubin do not rise to a level where it gets deposited in the brain. The main complication of hyperbilirubinemia is bilirubin-induced neuronal dysfunction or BIND. When bilirubin gets deposited in the brain, the damage is irreversible. “The babies will have poor feeding. Sometimes, they can have fits and an arch in the back,” explains Dr Sandeep.
Treating hyperbilirubinemia
Dr Kumar says if the bilirubin level exceeds the threshold, the only treatment approach is phototherapy. “This modality makes use of a special blue light. It changes the structure of bilirubin and makes it easily digestible so that it gets excreted through the urine and stool. Once we start phototherapy, we check the bilirubin levels within six to eight hours, depending on the severity of the jaundice. We then evaluate the phototherapy chart. If the levels are below the threshold, we stop the phototherapy,” he shares.
The therapy, while administered continuously, is stopped if the baby is crying or wants to feed. In such cases, the mother can take the baby out to comfort and feed them. “Once the feeding is done, the baby is kept in the light again,” adds Dr Kumar.
Recovery signs
Ensuring that the baby feeds well can help manage and control hyperbilirubinemia. Once the yellowish coloring in the baby’s skin reduces, they start feeding properly, putting on weight and passing a good amount of urine and yellow-colored stools. This indicates that the baby is getting better.
Takeaways
- High levels of bilirubin, a waste product of dead RBCs, can be an indicator of liver malfunction.
- High levels of bilirubin, referred to as hyperbilirubinemia, can cause jaundice.
- While most babies develop jaundice during neonatal age, they usually recover on their own.
- The risk factors for neonatal jaundice also include birth weight, gestational age and Rh incompatibility between the mother and the baby.
- If the bilirubin levels exceed the threshold, treatment is done with phototherapy.
- Ensuring that the baby feeds well can help manage hyperbilirubinemia.
