Neonatal jaundice

Background

• Neonatal jaundice can affect up to 84% of term newborns and is often a benign process that is quickly corrected once identified. It is also the most common cause for hospital readmission for neonates post birth.
• The most important piece of the evaluation is distinguishing between unconjugated and conjugated hyperbilirubinemia since a conjugated (direct) hyperbilirubinemia is always pathologic and often more severe

Risk Factors for Neonatal Jaundice

• Isoimmune hemolytic disease
• G6PD deficiency
• Asphyxia
• Significant lethargy
• Temperature instability
• Sepsis
• Acidosis
• Prematurity
• Poor PO intake

Clinical Features

• Jaundice
• Scleral icterus
• Lethargy (if progression to severe elevation)

Differential Diagnosis

Indirect (Unconjugated) Hyperbilirubinemia

More common causes are listed first, followed by less common causes

• Breast milk jaundice
  • Due to substances in milk that inhibits glucuronyl transferase. It may start as early as 3rd day and reaches peak by 3rd week of life. It is unlikely to cause kernicterus
• Breast feeding jaundice
  • Patient does not receive adequate oral intake which then causes reduced bowel movement/bilirubin excretion. Best diagnosed by looking for signs of dehydration and comparing weight to birth weight.
• Blood group incompatibility: ABO, Rh factor, minor antigens
• Diabetic mother/gestational diabetes
• Internal hemorrhage
• Physiologic jaundice
• Polycythemia
• Sepsis
• Hemoglobinopathies: thalassemia
• Red blood cell enzyme defects: G6PD Deficiency, pyruvate kinase
• Red blood cell membrane disorders: spherocytosis, ovalocytosis
• Hypothyroidism
• Immune thrombocytopenic purpura
• Mutations of glucuronyl transferase (i.e., Crigler-Najjar syndrome, Gilbert syndrome)

Direct (Conjugated) Hyperbilirubinemia

Conjugated bilirubinemia implies a hepatic or post hepatic cause. More common causes are listed first.

• Hyperalimentation cholestasis
• Neonatal hepatitis
• Cytomegalovirus infection
• Sepsis
• TORCH infection
• Biliary atresia
• Cystic fibrosis
• Hepatic infarction
• Inborn errors of metabolism (e.g., galactosemia, tyrosinosis)

Evaluation

• The most important component of the workup is differention of direct vs indirect bilirubinemia
• See BiliTool and the phototherapy guide for total bilirubin cutoff by age recommendations
• History extremely important
  • Mother's blood type (important if mother is RH negative or O blood type)
  • Assess for any signs of decreasing oral intake or signs of dehydration?
  • Baby's general appearance (well appearing?)
• Total bilirubin/Direct bilirubin levels
• CBC (for evaluation of hemolytic anemia or polycythemia vera)
• Consider coombs or T&S (mom & baby)

Management

• Breast Milk Jaundice
  • Do not need to routinely stop breast-feeding
  • Treat with phototherapy when necessary
• Breast-Feeding Jaundice (Starvation Jaundice)
  • Supplement with expressed breast milk or formula
• Exchange transfusion
  • Consider if signs of bilirubin encephalopathy, typically only occurs when the indirect bili level exceeds 25
    • Hypertonia, arching, retrocollis, opisthotonos
• Direct hyperbilirubinemia
  • If new diagnosis, always admit to the hospital for further evaluation

Phototherapy Guidelines

Total Bilirubin Cutoff by Risk Group

Age	Low Risk	Medium Risk	High Risk
Birth	7.0	5.0	4.0
24h	11.5	9.0	8.0
48h	15	14	10
72h	17.5	15	14
96h	20	17.5	14.5
5+days	21	17.5	15

• Low Risk: ≥38 weeks + no risk factors
• Medium Risk: (≥38 weeks + risk factors) or (35-37 weeks and no risk factors)
• High Risk: 35-37 weeks + risk factors

Note: Phototherapy is only used for an indirect hyperbilirubinemia

See Also

• Neonatal jaundice
• Neonatal resuscitation
• Jaundice
• Kernicterus

External Links

• BiliTool

References

Authors

Ross Donaldson