College of American Pathologists
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  Sudden Infant Death Syndrome


Posted October 5, 2007


The College of American Pathologists (CAP) supports the scientific position that the diagnosis of SIDS is one of exclusion rather than one of cause and, therefore, requires a complete post-mortem examination and appropriate testing. Further, the CAP encourages the proactive education of parents of newborns, the lay public, physicians and healthcare professionals to advocate the elimination of known SIDS risk factors, such as prone sleeping, soft bedding and household cigarette smoke.

Information Highlights

  • Sudden infant death syndrome, or SIDS, is also known as crib death or cot death.
  • SIDS is the sudden and unexpected death of an infant less than one year of age that remains unexplained after a complete autopsy, toxicology, scene investigation, and review of the medical records.
  • To classify a death as SIDS, one must rule out other causes of death by such a complete post-mortem examination.
  • SIDS is the leading cause of death in infants between one month and one year of age.
  • The cause of SIDS is unknown; however, researchers have been able to identify several risk factors that are associated with SIDS.
  • By reducing risk factors we have seen a decrease in the rate of SIDS worldwide.


  • SIDS is defined as the sudden, unexpected death of an infant under the age of one year, and generally greater than the age of one month, that remains unexplained after a complete autopsy including toxicology, scene investigation, and review of the medical records.
  • The cause of SIDS, or whether SIDS is a true syndrome, is unknown. The manner of death is presumably natural.
  • SIDS is a diagnosis of exclusion.
  • SIDS is the leading cause of postneonatal mortality in the U.S.
  • SIDS is more common in winter months, and usually occurs during infant sleep usually.
  • Reported risk factors for SIDS include low birth weight, premature birth, male sex, black race, maternal smoking before or after birth, lack of breastfeeding, bedsharing or use of inappropriate sleeping environments such as couches, and prone sleeping position.
  • The American Academy of Pediatrics started the “Back to Sleep” campaign in 1992 to promote safe sleeping positions in infants, which greatly reduced the SIDS case rate over the next decade.
  • Specific areas to be on the lookout are plastic bags or sheets near the infant, abundant fluffy bedding or stuffed animals, areas of possible wedging, or damaged cribs.
  • A scene investigation must be completed in all cases of suspected SIDS and should include examination of the sleeping environment, including description of the bedding, location, room temperature (overheating), sleep position, fellow sleepers (bedsharing/co-sleeping), and clothing.
  • The medical records should be obtained for review.
  • The autopsy in SIDS cases commonly shows no specific findings.