Neonatal Jaundice, Classification and Diagnosis
- Can get blood from the finger or heel prick.
- If possible, take venous blood.
Neonatal jaundice classification
- Neonatal jaundice can be classified as:
- Unconjugated hyperbilirubinemia.
- There is a risk of the development of kernicterus.
- Conjugated hyperbilirubinemia.
- This type of jaundice is characterized by an increased conjugated bilirubin >1.5 mg/dL (24 µmol/L).
- The most important cause is idiopathic neonatal hepatitis and biliary atresia.
- This type may be seen in newborns as a complication of parenteral nutrition.
- Neonatal jaundice can also be classified as:
- Physiologic jaundice.
- Pathological jaundice.
Physiologic jaundice of the newborn:
- Benign Physiologic jaundice of the newborn appears in the first 2 to 3 days (first few days of birth).
- Rarely does bilirubin rise to 5 mg/dL/day.
- The peak level reaches a peak level within the first 4 to 5 days.
- Bilirubin level remains elevated for <2 weeks.
- Rarely it exceeds >20 mg/dL.
- Factors contributing to physiologic jaundice are:
- The bilirubin level increased because of the short life of RBCs.
- There is a decreased level of glucuronyltransferase enzyme in the first few days of birth.
- There is the exposure of breastfeeding infants to inhibitors of bilirubin conjugation present in breast milk.
- Hemolytic disease leading to jaundice:
- Rh-incompatibility is when the Rh-fetus is Rh-positive, and the fetus is Rh-positive.
- Infants become jaundiced with unconjugated bilirubin in the first or second days of life.
- These babies may develop kernicterus.
- Breast milk hyperbilirubinemia:
- It is seen in 30% of the breastfed newborns.
- The exact cause is unknown.
- This condition lasts for a few weeks.
- It can be treated by discontinuing breastfeeding.
Pathological neonatal jaundice:
- This jaundice in newborns may appear in the first 24 hours.
- It keeps on rising in the first week of age.
- It may persist for more than 10 days.
- Total bilirubin may be >12 mg/dL.
- With a single-day increase of >5 mg/dL/day, the rise is quick.
- Conjugated (direct bilirubin) will be >2 mg/dL.
- Conjugated bilirubin levels up to 2 mg/dL are found in infants by one month of age, and this will remains through adult life.
- This is seen in the newborn, where the liver is immature and lacks sufficient conjugating enzymes. This will lead to an increased amount of unconjugated bilirubin.
- This unconjugated bilirubin can cross the blood-brain barrier and give rise to encephalopathy (Kernicterus).
- Bilirubin above 15 mg /dl in the newborn needs immediate treatment.
- This is treated by exchange of blood transfusion or light phototherapy.
Differential diagnosis of neonatal jaundice:
|Clinical conditions||Conjugated bilirubinemia||Unconjugated bilirubinemia|
- Newborn babies are exposed to phototherapy.
- The baby is exposed to 450 nm, which will change bilirubin into water-soluble and excreted into the bile.
- Exchange blood transfusion is needed when the bilirubin level rises above 15 mg/dL.
Bilirubin levels that may require treatment in a full-term, healthy baby:
|The period of infants||Bilirubin level||Treatment|
|24 hours or younger infants||>10 mg/dL (>170 mmol/L)||Needed|
|25 to 48 hours of infants||>15 mg/dL (>255 mmol/L)||Needed|
|49 to 72 hours of infants||>18 mg/dL (>305 mmol/L)||Needed|
|Older than 72 hours of infants||>20 mg/dL (>340 mmol/L)||Needed|
Panic value of bilirubin in neonates:
- >15 mg/dL (>250 µmol/L). It may damage the brain and leads to mental retardation in infants.
Questions and answers:
Q 1: What is the bilirubin level for blood exchange in the newborn.
Q 2: How to treat physiologic jaundice.