II. Epidemiology
- Jaundice Incidence in full term infants: 60%
- Jaundice Incidence in Preterm Infants: 80%
III. Pathophysiology: Physiologic Jaundice
- See Breast Feeding Jaundice
- Mechanisms of physiologic Neonatal Jaundice
- Increased Bilirubin production (2-3 fold over older infants)
- High fetal Hemoglobin turn-over (short Half-Life)
- Impaired Bilirubin conjugation
- Immature hepatic glucuronosyl transferase
- Decreased Bilirubin excretion
- Increased Bilirubin production (2-3 fold over older infants)
- Physiologic Jaundice
- Transient limitation of Bilirubin conjugation (immature hepatic glucuronosyl transferase)
- Increased Hemolysis
- Hemoglobin drops from 20 to 12 in first week
- Exaggerated Physiologic Jaundice
- Low glucuronyl transferase (Hepatic immaturity)
- Risk factors
- Breast Feeding Jaundice
- Prematurity
- Asian ethnicity
- Weight loss
IV. Signs: Jaundice
-
General
- Visual Jaundice indicates Total Bilirubin >4 mg/dl
- Physiologic Jaundice is not present on Day 1
- Visual inspection is not an accurate screening tool (misses cases of severe Hyperbilirubinemia)
- Level of Jaundice correlates with Bilirubin level (inexact)
V. Differential Diagnosis
VI. Labs: Bilirubin
- See Neonatal Bilirubin
- Transcutaneous Bili Meter
- Accurate in white infants
- Overestimates Bilirubin in black infants
- Do not use to monitor infants on Phototherapy
VII. Labs: Secondary Cause
- See Nonphysiologic Neonatal Jaundice for additional evaluation
VIII. Evaluation: Jaudice Monitoring before hospital discharge
- Visually inspect skin with Vital Signs (at least every 8 hours)
- Visual inspection alone has low Test Sensitivity (misses cases of severe Hyperbilirubinemia)
- Confirming observation with transcutaneous or Serum Bilirubin is preferred
- Moyer (2000) Arch Pediatr Adolesc Med 154:391-4 [PubMed]
- Obtain Transcutaneous Bilirubin or Serum Bilirubin
- Obtain Neonatal Bilirubin based on risk (preferred method)
- See Risk Score for Neonatal Hyperbilirubinemia (score of 8 or more indicates testing)
- Often part of hospital directed universal screening (e.g. all newborns at 24 hours)
- Universal screening is controversial
- Estimated to cost >$5 million in U.S. annually to prevent a single case of Kernicterus
- Increases Phototherapy rates without evidence that it decreases the risk of Bilirubin Encephalopathy
- Trikalinos (2009) Pediatrics 124(4): 1162-71 [PubMed]
- Obtain for Jaundice
- Neonatal Jaundice in the first 24 hours
- Neonatal Jaundice that appears excessive (e.g. below nipple line)
- Neonatal Jaundice that is difficult to assess on exam
- Do not rely solely on appearance of Jaundice as a screening indication (misses cases of severe Hyperbilirubinemia)
- Obtain Neonatal Bilirubin based on risk (preferred method)
IX. Evaluation: Jaundice Monitoring after hospital discharge
- Based on age
- Discharge before 24 hours old: Reevaluate by 72 hours old
- Discharge before 48 hours old: Reevaluate by 96 hours old
- Discharge before 72 hours old: Reevaluate by 120 hours old
- Based on risk factors
- See Severe Neonatal Hyperbilirubinemia Risk Factors
- Number of risk factors dictates timing of follow-up (typically within 24-48 hours)
X. Management
- See Phototherapy Indications
- See Breast Feeding Jaundice
XI. Prevention
- Adequate early nutrition and hydration
- See Breast Feeding Technique
- See Infant Feeding
- See Formula Feeding
- Do not supplement with dextrose water or plain water
- Monitoring
- See Evaluation above
XII. Complications
- Kernicterus is most linked to nonphysiologic causes
-
Kernicterus has been associated with physiologic causes
- Physiologic Jaundice
- Exaggerated Jaundice
- Breast Feeding Jaundice