Sudden infant death syndrome

Sudden infant death syndrome is the 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, cannabis, opiates, 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, an expert panel convened by the National Institute of Child Health and Human Development defined SIDS as the sudden death of an infant under 1 year of age with the cause of death unclear 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 The American Academy of Pediatrics use the following definition for unexplained sudden death in infancy or SIDS: ‘The sudden unexpected death of an apparently healthy infant aged <1 year, in which investigation, autopsy, medical history review, and appropriate laboratory testing fail to identify a specific cause, including cases that meet the definition of SIDS’.[3]Moon RY, Carlin RF, Hand I, et al. Sleep-related infant deaths: updated 2022 recommendations for reducing infant deaths in the sleep environment. Pediatrics. 2022 Jul 1;150(1):e2022057990. https://www.doi.org/10.1542/peds.2022-057990 http://www.ncbi.nlm.nih.gov/pubmed/35726558?tool=bestpractice.com ​ 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 ​​​​