Sudden infant death syndrome


  • Abbreviation: SIDS
  • Unexpected death of infants <1yr for which no pathologic cause can be determined
    • Most deaths occur between 2-4 months of age
    • Rare in <1 month of age
  • Diagnosis of exclusion

Risk Factors

  • Prone sleeping
    • Odds ratio of 4.92, one of biggest modifiable risk factors
    • Likely from combination of hypercarbia and hyperthermia (heat dissipated through head)
  • Soft bedding
  • Bed-sharing
  • Parental smoking
  • URI
  • Male sex
  • Prematurity / Developmental delay
  • Socioeconomic disadvantage
  • Mothers <20 yo
  • Maternal exposure to smoking, alcohol, drugs of abuse

Protective Factors

  • Use of pacifier
  • Breastfeeding
  • Immunizations
  • Home monitoring is NOT protective
  • Recommend safe sleep to all families (the ABC's = Alone, on Back, in Crib)

Clinical Features

  • Unexpected death of infants <1yr for which no pathologic cause can be determined

Differential Diagnosis

Sick Neonate



  • Examine for signs of nonaccidental trauma
    • Bruising, petechiae (especially to face on conjunctivae), torn frenulum, blood in mouth or nares
  • SIDS is a post-mortem diagnosis; ED chart should read "sudden unexpected death in infancy"


  • Infants with rigor mortis, livedo reticulrais, pH <6, or reduced temperature in absence of environmental hypothermia should not be resuscitated
  • Do not manipulate body - all cases require evaluation by coroner/ME


  • Deceased, by definition

See Also


  1. Brousseau T, Sharieff GQ. Newborn emergencies: the first 30 days of life. Pediatr Clin North Am. 2006 Feb;53(1):69-84, vi.
  • The Sudden Infant Death Syndrome. N Engl J Med 2009; 361:795-805