Duration of Physiological Jaundice in Newborns
Physiological jaundice in newborns typically disappears within 1-2 weeks in term infants, with peak bilirubin levels occurring at 72-96 hours of age and resolving thereafter. 1, 2
Understanding Physiological Jaundice
Physiological jaundice is characterized by:
- Mild, unconjugated hyperbilirubinemia affecting nearly all newborns
- Peak bilirubin levels of 5-6 mg/dL (86-103 μmol/L) at 72-96 hours after birth
- Levels typically do not exceed 17-18 mg/dL (291-308 μmol/L) 2
- Resolution within 1-2 weeks in most term infants
Important Variations
- In Asian infants, bilirubin levels may not peak until 7 days of age 2
- In infants born at 35-37 weeks' gestation, jaundice may also peak later and persist longer 2
- Male infants tend to remain jaundiced for significantly longer than female infants 3
When to Suspect Pathological Jaundice
Jaundice should be considered pathological and requires further evaluation if:
- It appears within the first 24 hours after birth 1
- Persists beyond 2 weeks of age 1
- Bilirubin levels rise rapidly (crossing percentiles on the nomogram) 4
- Total serum bilirubin exceeds physiological levels (>17-18 mg/dL) 2
Monitoring and Follow-up
For infants with jaundice:
- Measure total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) if jaundice appears in the first 24 hours 4
- Follow the American Academy of Pediatrics nomogram to interpret bilirubin levels according to the infant's age in hours 4
- Schedule appropriate follow-up based on discharge timing and bilirubin levels 1
- For jaundice persisting beyond 2 weeks, urgent evaluation is needed to rule out biliary atresia, regardless of stool color 1
Risk Factors for Prolonged Jaundice
Several factors may extend the duration of physiological jaundice:
- Prematurity (gestational age <38 weeks) 1
- Exclusive breastfeeding (breastfed infants may have higher bilirubin levels) 1
- Significant weight loss after birth (>10%) 1
- Presence of cephalohematoma or significant bruising 1
- Male gender 3
Management Considerations
If jaundice persists or worsens:
- Phototherapy should be initiated based on TSB thresholds according to the AAP phototherapy nomogram 1
- Most term babies with physiological jaundice respond to a short period of phototherapy 5
- After discontinuing phototherapy, a follow-up bilirubin measurement within 24 hours is recommended to ensure levels continue to decline 1
Caution
Jaundice persisting beyond 2 weeks requires urgent evaluation, as it may indicate pathological conditions such as biliary atresia or other liver disorders that require prompt intervention 1.