Neonatal Jaundice

Jaundice is visible at serum bilirubin 85-120 μmol/L (sclera, mucous membranes, palmar creases, tip of nose) – hyperbilirubinemia

Risk factors

  • Maternal factors
    • Blood type ABO or Rh incompatibility
    • Breastfeeding
    • Drugs: diazepam, oxytocin
    • Ethnicity: Asian, Native American
    • Maternal illness: gestational diabetes
  • Neonatal factors
    • Birth trauma: cephalohematoma, cutaneous bruising, instrumented delivery
    • Drugs: sulfisoxazole acetyl with erythromycin ethylsuccinate (Pediazole), chloramphenicol (Chloromycetin)
    • Excessive weight loss after birth
    • Infections: TORCH
    • Infrequent feedings
    • Male gender
    • Polycythemia
    • Prematurity
    • Previous sibling with hyperbilirubinemia

Bilirubin toxicity

  • Kernicterus: neurologic consequences of the deposition of unconjugated bilirubin in brain tissue (basal ganglia and brain-stem nuclei)

Early

Late

Chronic

Lethargy

Irritability

Athetoid cerebral palsy

Poor feeding

Opisthotonos

High-frequency hearing loss

High pitched cry

Seizures

Paralysis of upward gaze

Hypotonia

Apnea

Dental dysplasia

 

Oculogyric crisis

Mild mental retardation

 

Hypertonia

 

 

Fever

 

 

Physiologic jaundice
Bilirubin is the final product of heme degradation. At physiologic pH, bilirubin is insoluble in plasma and requires protein binding with albumin. After conjugation in the liver by glucuronyl transferase, it is excreted in bile. Hyperbilirubinemia develops due to increased hematocrit, decreased RBC lifespan, increased enterohepatic circulation and immature glucuronyl transferase (slow conjugation).

  • Term infants: onset 2-3days, resolution by 7days
  • Premature: higher peak and longer duration

Breastfeeding and Jaundice

  • Breastfeeding jaundice (common)
    • Early-onset exaggerated physiologic jaundice
    • Relative caloric deprivation in the first few days of life due to lack of milk production
    • Mild dehydration
  • Breast milk jaundice (rare)
    • Late onset – onset 4-7days, peaking 2nd-3rd week of life
    • Inhibitor of glucuronyl transferase found in breast milk

Pathologic jaundice

  • Presenting within 24hr

Increased bilirubin load

  • Hemolytic causes
    • Characteristics: increased unconjugated bilirubin level, >6 percent reticulocytes, hemoglobin concentration of <13 g per dL (130 g per L)
    • Coombs’ test positive: Rh factor incompatibility, ABO incompatibility, minor antigens
    • Coombs’ test negative: red blood cell membrane defects (spherocytosis), red blood cell enzyme defects (G6PD deficiency), drugs , abnormal red blood cells, sepsis
  • Nonhemolytic causes
    • Characteristics: increased unconjugated bilirubin level, normal percentage of reticulocytes
      • Extravascular sources: cephalohematoma, bruising, central nervous system hemorrhage, swallowed blood
      • Polycythemia: fetal-maternal transfusion, delayed cord clamping, twin-twin transfusion
      • Exaggerated enterohepatic circulation: cystic fibrosis, ileal atresia, pyloric stenosis, Hirschsprung’s disease, breast milk jaundice

Decreased bilirubin conjugation

  • Characteristics: increased unconjugated bilirubin level, normal percentage of reticulocytes
    • Physiologic jaundice
    • Crigler-Najjar syndrome types 1 and 2
    • Gilbert syndrome
    • Hypothyroidism
    • Breast milk jaundice

Impaired bilirubin excretion

  • Characteristics: increased unconjugated and conjugated bilirubin level, negative Coombs’ test, conjugated bilirubin level of >2 mg per dL (34 µmol per L) or >20% of total serum bilirubin level, conjugated bilirubin in urine
    • Biliary obstruction: biliary atresia, choledochal cyst, primary sclerosing cholangitis, gallstones, neoplasm
    • Infection
    • Metabolic disorder: alpha1 antitrypsin deficiency, cystic fibrosis, galactosemia, glycogen storage disease, Gaucher’s disease, hypothyroidism, Wilson’s disease, Niemann-Pick disease
    • Chromosomal abnormality: Turner’s syndrome, trisomy 18 and 21 syndromes
    • Drugs: aspirin, acetaminophen, sulfa, alcohol, rifampin (Rifadin), erythromycin, corticosteroids, tetracycline

Investigation

  • CBCD, reticulocyte count, peripheral smear, total bilirubin, conjugated bilirubin
  • Lytes (dehydration)

Management

  • Consult graph for levels of bilirubin requiring phototherapy or exchange transfusion
  • Phototherapy: transforms bilirubin into lumirubin which is water soluble (can cause dehydration and loose stools –> IV fluids)
  • IVIG
  • Exchange transfusion removes partially hemolyzed and antibody-coated erythrocytes and replaces them with uncoated donor red blood cells that lack the sensitizing antigen

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