Sudden infant death syndrome

Leading cause of infant death beyond the neonatal period.

Incidence roughly 1 in 2000 infants.

Peak incidence between 1 and 3 months of age, although events may occur up to 12 months of age.

Risk factors include exposure to tobacco smoke (antenatally and postnatally); prone and side sleeping; bed-sharing during sleep; a sleep environment that includes soft mattress and/or sleeping surface (including sofa or armchair), and placement of soft sleep bedding; over-bundling/over-heating; prematurity; exposure to alcohol and illicit drugs (antenatally and postnatally); and viral infection. Several risk factors may co-exist in any given patient.

Protective factors include use of a dummy during sleep, immunisation, and breastfeeding.

Careful evaluation of death by trained forensics teams is necessary to rule out other causes of death, including suffocation, asphyxia, entrapment, infection, ingestions, metabolic diseases, arrhythmia-associated cardiac channelopathies, and trauma (accidental or non-accidental).

The term 'sudden infant death syndrome' (SIDS) was first used, and an early definition described, at the 2nd International Conference on the Causes of Sudden Death in Infants in 1969.[1]Beckwith JB. Discussion of terminology and definition of the sudden infant death syndrome. In: Bergman AB, Beckwith JB, Ray CG, eds. Sudden infant death syndrome: proceedings of the Second International Conference on the Causes of Sudden Death in Infants. Seattle, WA: University of Washington Press; 1970:14-22. In 1991, the definition was modified by a panel convened by the National Institute of Child Health and Human Development. The panel defined SIDS as "The sudden death of an infant under 1 year of age, which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and a review of the clinical history".[2]Willinger M, James LS, Catz C. Defining the sudden infant death syndrome (SIDS): deliberations of an expert panel convened by the National Institutes of Child Health and Human Development. Pediatr Pathol. 1991;11:677-84. http://www.ncbi.nlm.nih.gov/pubmed/1745639?tool=bestpractice.com This remains the widely accepted definition, and is the preferred definition of the American Academy of Pediatrics Task Force on Sudden Infant Death Syndrome.[3]Task Force on Sudden Infant Death Syndrome. Policy statement - SIDS and other sleep-related infant deaths: updated 2016 recommendations for a safe infant sleeping environment. Pediatrics. 2016 Nov;138(5):e20162938. http://pediatrics.aappublications.org/content/138/5/e20162938 http://www.ncbi.nlm.nih.gov/pubmed/27940804?tool=bestpractice.com Although some have advocated the addition of the criterion that onset of the fatal event seems to be associated with sleep,[4]Krous HF, Beckwith JB, Byard RW, et al. Sudden infant death syndrome (SIDS) and unclassified sudden infant death (USID): a definitional and diagnostic approach. Pediatrics. 2004 Jul;114(1):234-8. http://www.ncbi.nlm.nih.gov/pubmed/15231934?tool=bestpractice.com [5]Bajanowski T, Vege A, Byard RW, et al. Sudden infant death syndrome (SIDS) - standardised investigations and classification: recommendations. Forensic Sci Int. 2007 Jan 17;165(2-3):129-43. http://www.ncbi.nlm.nih.gov/pubmed/16806765?tool=bestpractice.com this criterion remains controversial.