Last reviewed: 28 Dec 2021
Last updated: 11 Oct 2019



History and exam

Other diagnostic factors

  • absence of metabolic disease
  • absence of irritability, lethargy
  • absence of fever, cough, or nasal congestion
  • absence of trauma

Risk factors

  • side, prone, or inclined position at last sleep
  • bed-sharing/co-sleeping
  • soft sleeping surface/environment
  • maternal cigarette smoking
  • increasing number of smokers in house
  • smoking in same room as child
  • formula feeding
  • non-use of a dummy
  • premature birth
  • maternal substance use/abuse
  • single mother
  • lower maternal age
  • low level of antenatal care
  • low level of maternal education
  • low socio-economic status
  • black or American Indian
  • lack of immunisation

Diagnostic investigations

Investigations to consider

  • blood culture
  • cerebrospinal fluid culture
  • urine culture
  • serum chemistry
  • urine chemistry
  • photographic record
  • skeletal survey
  • anatomical pathology
  • vitreous chemistry
  • muscle biopsy

Treatment algorithm



Rachel Y. Moon, MD, FAAP

Professor of Pediatrics

University of Virginia School of Medicine




RYM receives grant funding from the National Institutes of Health, receives honoraria for speaking at various conferences, and is a board member of the International Society for the Study and Prevention of Perinatal and Infant Death. She has provided expert testimony in a case of an infant who died suddenly and unexpectedly.


Dr Rachel Y. Moon would like to gratefully acknowledge Dr John W. Berkenbosch, a previous contributor to this topic.


JWB declares that he has no competing interests.

Peer reviewers

Peter Fleming, MB ChB, PhD

Professor of Infant Health & Developmental Physiology

FSID Research Unit

Institute of Child Life and Health

St Michaels Hospital




PF is an author of a number of references cited in this topic.

Thomas Hegyi, MD

Professor and Vice-Chair

Department of Pediatrics

UMDNJ-Robert Wood Johnson Medical School

New Brunswick



TH declares that he has no competing interests.

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