Editing SIDS

{{short description|Sudden unexplained death of a child who is less than one year of age}}
{{Other uses}}
{{Cs1 config|name-list-style=vanc}}
{{Use dmy dates|date=December 2017}}
{{Use American English|date=December 2017}}
{{Infobox medical condition (new)
| name          = Sudden infant death syndrome
| synonyms      = {{ hlist | Cot death | crib death }}
| image         = Safe Sleep logo.svg
| alt           = Safe to Sleep logo
| caption       = The [[Safe to Sleep]] campaign encourages having infants sleep on their backs to reduce the risk of SIDS.
| field         = {{ hlist | [[Pediatrics]] | [[Forensic pathology]] }}
| onset         = One to four months in age<ref name=NIH2013Epi/>
| causes        = Unknown 
| risks         = {{ ubl | Sleeping on belly or side | Overheating | Exposure to [[tobacco smoke]] | [[Preterm birth]] }}
| diagnosis     = {{ hlist | Investigation | [[Autopsy]] }}
| differential  = {{ ubl | [[Infection]]s | [[Genetic disorder]]s | Heart problems }}
| prevention    = {{ ubl | Sleeping supine | [[Pacifier]] use | [[Breastfeeding]] }}
| frequency     = 1 in 1,000–10,000
}}

<!-- Definition and symptoms -->
'''Sudden infant death syndrome''' ('''SIDS'''), sometimes known as '''cot death''' or '''crib death''', is the sudden unexplained [[death]] of a child of less than one year of age. Diagnosis requires that the death remain unexplained even after a thorough [[autopsy]] and detailed death scene investigation.<ref name=CDC2013Diag>{{cite web | work = Centers for Disease Control and Prevention | title = Sudden Infant Death |url=https://www.cdc.gov/sids/ |url-status=deviated |archive-url=https://web.archive.org/web/20130318045725/http://www.cdc.gov/sids/ |archive-date=March 18, 2013 |access-date=March 13, 2013}}</ref> SIDS usually occurs during [[sleep]].<ref name=Kin2009/> Typically death occurs between the hours of midnight and 9:00 a.m.<ref>{{cite book| vauthors = Gilbert-Barness E, Spicer DE, Steffensen TS | chapter = Sudden Death Syndrome |title=Handbook of pediatric autopsy pathology |date=2013|publisher=Springer New York|location=New York, NY|isbn=9781461467113|pages=654|edition=Second| chapter-url = https://books.google.com/books?id=yaPjAAAAQBAJ&pg=PA654|access-date=15 September 2017|archive-date=14 January 2023|archive-url=https://web.archive.org/web/20230114071655/https://books.google.com/books?id=yaPjAAAAQBAJ&pg=PA654|url-status=live}}</ref> There is usually no noise or evidence of struggle.<ref>{{cite book | vauthors = Sethuraman C, Coombs R, Cohen MC |chapter=Sudden Unexpected Death in Infancy | chapter-url=https://books.google.com/books?id=t33sAwAAQBAJ&pg=PA319 | veditors = Cohen MC, Scheimberg I |title=Pediatric & Perinatal Autopsy Manual  |publisher=Cambridge |year=2014 |isbn=9781107646070 |pages=319 }}</ref> SIDS remains the leading cause of infant mortality in Western countries, constituting half of all post-neonatal deaths.<ref>{{cite book | vauthors = Raven L | chapter = Sudden Infant Death Syndrome: History |date=2018| chapter-url= http://www.ncbi.nlm.nih.gov/books/NBK513390/ | veditors = Duncan JR, Byard RW | title = SIDS Sudden Infant and Early Childhood Death: The Past, the Present and the Future |place=Adelaide (AU)|publisher=University of Adelaide Press|isbn=978-1-925261-67-7|pmid=30035955|access-date=2020-09-28|archive-date=27 July 2022|archive-url=https://web.archive.org/web/20220727192826/https://www.ncbi.nlm.nih.gov/books/NBK513390/|url-status=live}}</ref>

<!-- Cause and diagnosis -->
The exact cause of SIDS is unknown.<ref name=NIH2013Cause>{{cite web|title=What causes SIDS?|url=http://www.nichd.nih.gov/health/topics/sids/conditioninfo/pages/causes.aspx|website=National Institute of Child Health and Human Development|access-date=9 March 2015|date=12 April 2013|url-status=live|archive-url=https://web.archive.org/web/20150402220510/http://www.nichd.nih.gov/health/topics/sids/conditioninfo/pages/causes.aspx|archive-date=2 April 2015}}</ref> The requirement of a combination of factors including a specific underlying susceptibility, a specific time in development, and an environmental stressor has been proposed.<ref name=Kin2009>{{cite journal | vauthors = Kinney HC, Thach BT | title = The sudden infant death syndrome | journal = The New England Journal of Medicine | volume = 361 | issue = 8 | pages = 795–805 | date = August 2009 | pmid = 19692691 | pmc = 3268262 | doi = 10.1056/NEJMra0803836 }}</ref><ref name=NIH2013Cause/> These environmental stressors may include sleeping on the stomach or side, overheating, and exposure to [[tobacco smoke]].<ref name=NIH2013Cause/> [[Overlaying|Accidental suffocation]] from [[bed sharing]] (also known as co-sleeping) or soft objects may also play a role.<ref name=Kin2009/><ref>{{cite web|title=Ways To Reduce the Risk of SIDS and Other Sleep-Related Causes of Infant Death|url=https://www.nichd.nih.gov/sts/about/risk/Pages/reduce.aspx|website=NICHD|access-date=2 March 2016|date=20 January 2016|url-status=live|archive-url=https://web.archive.org/web/20160307132750/https://www.nichd.nih.gov/sts/about/risk/Pages/reduce.aspx|archive-date=7 March 2016}}</ref> Another risk factor is being born before 37 [[Gestational age (obstetrics)|weeks of gestation]].<ref name=NIH2013Epi/> Between 1% and 5% of SIDS cases are estimated to be misidentified [[infanticide]]s caused by intentional [[asphyxia|suffocation]].<ref name="pediatrics-hymel">{{cite journal |last1=Hymel |first1=Kent P. |title=Distinguishing sudden infant death syndrome from child abuse fatalities |journal=Pediatrics |date=July 2006 |volume=118 |issue=1 |pages=421–427 |doi=10.1542/peds.2006-1245 |pmid=16818592 |url=https://pubmed.ncbi.nlm.nih.gov/16818592/ |issn=1098-4275}}</ref><ref name="afp-milroy">{{cite journal | vauthors = Milroy CM, Kepron C | title = Ten Percent of SIDS Cases are Murder - or are They? | journal = Academic Forensic Pathology | volume = 7 | issue = 2 | pages = 163–170 | date = June 2017 | pmid = 31239971 | pmc = 6474533 | doi = 10.23907/2017.018 }}</ref> SIDS makes up about 80% of sudden and unexpected infant deaths (SUIDs).<ref name=Kin2009/> The other 20% of cases are often caused by [[infection]]s, [[genetic disorder]]s, and heart problems.<ref name=Kin2009/>

<!-- Prevention -->
The most effective method of reducing the risk of SIDS is putting a child less than one-year-old on their back to sleep.<ref name=NIH2013Epi/> Other measures include a firm mattress separate from but close to caregivers, no loose bedding, a relatively cool sleeping environment, using a [[pacifier]], and avoiding exposure to tobacco smoke.<ref name=Moon2012>{{cite journal | vauthors = Moon RY, Fu L | title = Sudden infant death syndrome: an update | journal = Pediatrics in Review | volume = 33 | issue = 7 | pages = 314–320 | date = July 2012 | pmid = 22753789 | doi = 10.1542/pir.33-7-314 }}</ref> [[Breastfeeding]] and [[immunization]] may also be preventative.<ref name=Moon2012/><ref name=NIH2014Pre/> Measures not shown to be useful include positioning devices and [[baby monitors]].<ref name=Moon2012/><ref name=NIH2014Pre>{{cite web|title=How can I reduce the risk of SIDS?|url=http://www.nichd.nih.gov/health/topics/sids/conditioninfo/pages/reduce-risk.aspx|website=National Institute of Child Health and Human Development|access-date=9 March 2015|date=22 August 2014|url-status=dead|archive-url=https://web.archive.org/web/20150227031841/http://www.nichd.nih.gov/health/topics/sids/conditioninfo/pages/reduce-risk.aspx|archive-date=27 February 2015}}</ref> Evidence is not sufficient for the use of fans.<ref name=Moon2012/> [[Grief counseling|Grief support]] for families affected by SIDS is important, as the death of the infant is unexpected, unexplained, and can cause suspicion that the infant may have been intentionally harmed.<ref name=Kin2009/>

<!-- Epidemiology -->
Rates of SIDS vary nearly tenfold in [[developed countries]] from one in a thousand to one in ten thousand.<ref name=Kin2009/><ref name=Dun2018>{{cite book | vauthors = Duncan JR, Byard RW | chapter = Sudden Infant Death Syndrome: An Overview|date=2018|url=http://www.ncbi.nlm.nih.gov/books/NBK513399/ | veditors = Duncan JR, Byard RW | title = SIDS Sudden Infant and Early Childhood Death: The Past, the Present and the Future |publisher=University of Adelaide Press|isbn=9781925261677|pmid=30035964|access-date=2019-08-01 |archive-date=2 July 2020|archive-url=https://web.archive.org/web/20200702043737/https://www.ncbi.nlm.nih.gov/books/NBK513399/|url-status=live}}</ref> Globally, it resulted in about 19,200 deaths in 2015, down from 22,000 deaths in 1990.<ref name="GBD2015De">{{cite journal | title = Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015 | journal = Lancet | volume = 388 | issue = 10053 | pages = 1459–1544 | date = October 2016 | pmid = 27733281 | pmc = 5388903 | doi = 10.1016/s0140-6736(16)31012-1 | display-authors = 6 | vauthors = Wang H, Naghavi M, Allen C, Barber RM, Bhutta ZA, Carter A, Casey DC, Charlson FJ, Chen AZ, Coates MM, Coggeshall M, Dandona L, Dicker DJ, Erskine HE, Ferrari AJ, Fitzmaurice C, Foreman K, Forouzanfar MH, Fraser MS, Fullman N, Gething PW, Goldberg EM, Graetz N, Haagsma JA, Hay SI, Huynh C, Johnson CO, Kassebaum NJ, Kinfu Y, Kulikoff XR }}</ref> SIDS was the third leading cause of [[infant mortality|death in children less than one year old]] in the United States in 2011.<ref name=CDC2012Epi>{{cite journal | vauthors = Hoyert DL, Xu J | title = Deaths: preliminary data for 2011 | journal = National Vital Statistics Reports | volume = 61 | issue = 6 | pages = 1–51 | date = October 2012 | pmid = 24984457 | url = https://www.cdc.gov/nchs/data/nvsr/nvsr61/nvsr61_06.pdf | url-status = live | archive-url = https://web.archive.org/web/20140202154454/http://www.cdc.gov/nchs/data/nvsr/nvsr61/nvsr61_06.pdf | archive-date = 2014-02-02 }}</ref> It is the most common cause of death between one month and one year of age.<ref name=NIH2013Epi/> About 90% of cases happen before six months of age, with it being most frequent between two months and four months of age.<ref name=Kin2009/><ref name=NIH2013Epi/> It is more common in boys than girls.<ref name=NIH2013Epi>{{cite web|title=How many infants die from SIDS or are at risk for SIDS?|url=http://www.nichd.nih.gov/health/topics/sids/conditioninfo/pages/risk.aspx|website=National Institute of Child Health and Human Development|access-date=9 March 2015|date=19 November 2013|url-status=live|archive-url=https://web.archive.org/web/20150402182125/http://www.nichd.nih.gov/health/topics/sids/conditioninfo/pages/risk.aspx|archive-date=2 April 2015}}</ref> Rates of SIDS have decreased by up to 80% in areas with [[Safe to Sleep|"Safe to Sleep" campaigns]].<ref name=Dun2018/>

==Definition==
[[File:Sudden infant death syndrome.webm|thumb|upright=1.35|Video explanation]]

The syndrome applies only to infants under one year of age.<ref name="NIH2013Def">{{cite web |date=27 June 2013 |title=Sudden Infant Death Syndrome |url=http://www.nichd.nih.gov/health/topics/sids/Pages/default.aspx |url-status=live |archive-url=https://web.archive.org/web/20150223190134/http://www.nichd.nih.gov/health/topics/sids/Pages/default.aspx |archive-date=23 February 2015 |access-date=9 March 2015 |website=National Institute of Child Health and Human Development}}</ref> SIDS is a [[diagnosis of exclusion]] and should be applied to only those cases in which an infant's death is sudden and unexpected, and remains unexplained after the performance of an adequate [[postmortem]] investigation, including:

# an [[autopsy]] (by an experienced pediatric [[pathologist]], if possible);
# investigation of the death scene and circumstances of the death; and
# exploration of the [[medical history]] of the infant and family.

After investigation, some of these infant deaths are found to be caused by suffocation, [[hyperthermia]] or [[hypothermia]], neglect or some other defined cause.<ref>{{cite web |url=https://www.cdc.gov/sids/aboutsuidandsids.htm |title=Sudden Unexpected Infant Death and Sudden Infant Death Syndrome: About SUID and SIDS |publisher=Centers for Disease Control and Prevention |access-date=April 16, 2016 |url-status=live |archive-url=https://web.archive.org/web/20160420200947/http://www.cdc.gov/sids/aboutsuidandsids.htm |archive-date=April 20, 2016 }}</ref>

Australia and New Zealand shifted to ''sudden unexpected death in infancy'' (SUDI) for professional, scientific, and coronial clarity:

{{blockquote|The term SUDI is now often used instead of sudden infant death syndrome (SIDS) because some coroners prefer to use the term 'undetermined' for a death previously considered to be SIDS. This change is causing a diagnostic shift in the mortality data.<ref>{{Cite web |date=Apr 2008 |title=Preventing sudden unexpected death in infancy |url=http://www.moh.govt.nz/moh.nsf/0/5118C5C5561CEC79CC2573A6000B3BBE |archive-url=https://web.archive.org/web/20091212171003/http://www.moh.govt.nz/moh.nsf/0/5118C5C5561CEC79CC2573A6000B3BBE |archive-date=2009-12-12 |website=Ministry of Health}}</ref>}} In addition, the US [[Centers for Disease Control and Prevention]] have proposed that such deaths be called ''sudden unexpected infant deaths'' (SUID) and that SIDS is a subset of SUID.<ref>{{cite web |url=https://www.cdc.gov/sids/pdf/sudden-unexpected-infant-death.pdf |title=Sudden Unexpected Infant Death |publisher=Centers for Disease Control and Prevention |access-date=April 16, 2016 |url-status=live |archive-url=https://web.archive.org/web/20160513173510/http://www.cdc.gov/sids/pdf/sudden-unexpected-infant-death.pdf |archive-date=May 13, 2016}}</ref>

===Age===
SIDS has a four-parameter [[lognormal]] [[age distribution]] that spares infants shortly after birth—the time of maximal risk for almost all other causes of non-trauma infant death.

By definition, SIDS deaths occur under the age of one year, with the peak incidence occurring when the infant is two to four months old. This is considered a critical period because the infant's ability to rouse from sleep is not yet mature.<ref name=Kin2009/>

==Risk factors==
The exact cause of SIDS is unknown.<ref name=NIH2013Cause/> Although studies have identified risk factors for SIDS, such as putting infants to bed on their bellies, there has been little understanding of the syndrome's biological process or its potential causes. Deaths from SIDS are unlikely to be due to a single cause, but rather to multiple risk factors.<ref>{{ cite book | vauthors = Byard RW | chapter = Sudden Infant Death Syndrome: Definitions |date=2018| chapter-url = http://www.ncbi.nlm.nih.gov/books/NBK513393/ | veditors = Duncan JR, Byard RW | title = SIDS Sudden Infant and Early Childhood Death: The Past, the Present and the Future |publisher=University of Adelaide Press|isbn=9781925261677|pmid=30035958|access-date=2019-08-01|archive-date=24 February 2021|archive-url=https://web.archive.org/web/20210224234544/http://www.ncbi.nlm.nih.gov/books/NBK513393/|url-status=live}}</ref> The frequency of SIDS does appear to be influenced by social, economic, or cultural factors, such as maternal education, race or ethnicity, or poverty.<ref name="pmid16254231">{{cite journal | vauthors = Pickett KE, Luo Y, Lauderdale DS | title = Widening social inequalities in risk for sudden infant death syndrome | journal = American Journal of Public Health | volume = 95 | issue = 11 | pages = 1976–1981 | date = November 2005 | pmid = 16254231 | pmc = 1449471 | doi = 10.2105/AJPH.2004.059063 }}</ref> SIDS is believed to occur when an infant with an underlying biological vulnerability, who is at a critical development age, is exposed to an external trigger.<ref name=Kin2009/> The following risk factors generally contribute either to the underlying biological vulnerability or represent an external trigger:

===Tobacco smoke===
SIDS rates are higher in babies of mothers who [[Smoking and pregnancy|smoke during pregnancy]].<ref name="sullivan"/><ref>[[Surgeon General of the United States|Office of the Surgeon General of the United States]] [http://www.surgeongeneral.gov/news/speeches/06272006a.html Report on Involuntary Exposure to Tobacco Smoke] {{webarchive|url=https://web.archive.org/web/20110806133133/http://www.surgeongeneral.gov/news/speeches/06272006a.html |date=2011-08-06 }}([http://www.surgeongeneral.gov/library/secondhandsmoke/report/fullreport.pdf PDF] {{webarchive|url=https://web.archive.org/web/20090205173605/http://www.surgeongeneral.gov/library/secondhandsmoke/report/fullreport.pdf |date=2009-02-05 }})</ref> Between no smoking and smoking one cigarette a day, on average, the risk doubles. About 22% of SIDS in the United States is related to maternal smoking.<ref>{{cite journal | vauthors = Anderson TM, Lavista Ferres JM, Ren SY, Moon RY, Goldstein RD, Ramirez JM, Mitchell EA | title = Maternal Smoking Before and During Pregnancy and the Risk of Sudden Unexpected Infant Death | journal = Pediatrics | volume = 143 | issue = 4 | pages = e20183325 | date = April 2019 | pmid = 30858347 | pmc = 6564075 | doi = 10.1542/peds.2018-3325 }}</ref> SIDS correlates with levels of [[nicotine]] and its derivatives in the baby.<ref name="Bajanowski">{{cite journal | vauthors = Bajanowski T, Brinkmann B, Mitchell EA, Vennemann MM, Leukel HW, Larsch KP, Beike J | title = Nicotine and cotinine in infants dying from sudden infant death syndrome | journal = International Journal of Legal Medicine | volume = 122 | issue = 1 | pages = 23–28 | date = January 2008 | pmid = 17285322 | doi = 10.1007/s00414-007-0155-9 | s2cid = 26325523 }}</ref> Nicotine and derivatives cause alterations in [[neurodevelopment]].<ref>{{cite journal | vauthors = Lavezzi AM, Corna MF, Matturri L | title = Ependymal alterations in sudden intrauterine unexplained death and sudden infant death syndrome: possible primary consequence of prenatal exposure to cigarette smoking | journal = Neural Development | volume = 5 | pages = 17 | date = July 2010 | pmid = 20642831 | pmc = 2919533 | doi = 10.1186/1749-8104-5-17 | doi-access = free }}</ref>

===Sleeping===
Placing an infant to sleep while lying on the belly or side rather than on the back increases the risk for SIDS.<ref name=Moon2012/><ref>{{cite journal | vauthors = Carlin RF, Moon RY | title = Risk Factors, Protective Factors, and Current Recommendations to Reduce Sudden Infant Death Syndrome: A Review | journal = JAMA Pediatrics | volume = 171 | issue = 2 | pages = 175–180 | date = February 2017 | pmid = 27918760 | doi = 10.1001/jamapediatrics.2016.3345 | s2cid = 25569308 }}</ref> This increased risk is greatest at two to three months of age.<ref name=Moon2012/> Elevated or reduced room temperature also increases the risk,<ref name=Moon2007>{{cite journal | vauthors = Moon RY, Horne RS, Hauck FR | title = Sudden infant death syndrome | journal = Lancet | volume = 370 | issue = 9598 | pages = 1578–1587 | date = November 2007 | pmid = 17980736 | doi = 10.1016/S0140-6736(07)61662-6 | url = http://adc.bmj.com/cgi/content/short/46/248/579-a | access-date = 14 February 2019 | url-status = live | s2cid = 24624496 | archive-url = https://web.archive.org/web/20210829073529/https://adc.bmj.com/content/46/248/579.2 | archive-date = 29 August 2021 | url-access = subscription }}</ref> as does excessive bedding, clothing, soft sleep surfaces, and [[stuffed animal]]s in the bed.<ref>{{cite journal | vauthors = Fleming PJ, Levine MR, Azaz Y, Wigfield R, Stewart AJ | title = Interactions between thermoregulation and the control of respiration in infants: possible relationship to sudden infant death | journal = Acta Paediatrica | volume = 82 | issue = Suppl 389 | pages = 57–59 | date = June 1993 | pmid = 8374195 | doi = 10.1111/j.1651-2227.1993.tb12878.x | s2cid = 44497216 }}</ref> [[Bumper pads]] may increase the risk of SIDS due to the risk of suffocation. They are not recommended for children under one year of age, as this risk of suffocation greatly outweighs the risk of head bumping or limbs getting stuck in the bars of the crib.<ref name=Moon2012/>

[[Co-sleeping|Sharing a bed]] with parents or siblings increases the risk for SIDS.<ref>{{cite journal | vauthors = McIntosh CG, Tonkin SL, Gunn AJ | title = What is the mechanism of sudden infant deaths associated with co-sleeping? | journal = The New Zealand Medical Journal | volume = 122 | issue = 1307 | pages = 69–75 | date = December 2009 | pmid = 20148046 }}</ref> This risk is greatest in the first three months of life, when the mattress is soft, when one or more persons share the infant's bed, especially when the bed partners are using drugs or alcohol or are smoking.<ref name=Moon2012/> The risk remains, however, even in parents who do not smoke or use drugs.<ref>{{cite journal | vauthors = Carpenter R, McGarvey C, Mitchell EA, Tappin DM, Vennemann MM, Smuk M, Carpenter JR | title = Bed sharing when parents do not smoke: is there a risk of SIDS? An individual level analysis of five major case-control studies | journal = BMJ Open | volume = 3 | issue = 5 | pages = e002299 | date = May 2013 | pmid = 23793691 | pmc = 3657670 | doi = 10.1136/bmjopen-2012-002299 }} {{open access}}</ref> The [[American Academy of Pediatrics]] thus recommends "room-sharing without bed-sharing", stating that such an arrangement can decrease the risk of SIDS by up to 50%. Furthermore, the academy has recommended against devices marketed to make bed-sharing "safe", such as "in-bed co-sleepers".<ref name=AAP2011>{{cite journal | vauthors = Moon RY | title = SIDS and other sleep-related infant deaths: expansion of recommendations for a safe infant sleeping environment | journal = Pediatrics | volume = 128 | issue = 5 | pages = 1030–1039 | date = November 2011 | pmid = 22007004 | doi = 10.1542/peds.2011-2284 | doi-access = free }}</ref>

Room sharing as opposed to solitary sleeping is known to decrease the risk of SIDS.<ref>{{cite book | vauthors = Young J, Shipstone R | chapter = Shared Sleeping Surfaces and Dangerous Sleeping Environments|date=2018| chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK513372/ | veditors = Duncan JR, Byard RW | title =SIDS Sudden Infant and Early Childhood Death: The Past, the Present and the Future|place=Adelaide (AU)|publisher=University of Adelaide Press|isbn=978-1-925261-67-7|pmid=30035939|access-date=2021-01-11|archive-date=4 November 2022|archive-url=https://web.archive.org/web/20221104162006/http://www.ncbi.nlm.nih.gov/books/NBK513372/|url-status=live}}</ref>

===Breastfeeding===
[[Breastfeeding]] is associated with a lower risk of SIDS.<ref>{{cite journal | vauthors = Hauck FR, Thompson JM, Tanabe KO, Moon RY, Vennemann MM | title = Breastfeeding and reduced risk of sudden infant death syndrome: a meta-analysis | journal = Pediatrics | volume = 128 | issue = 1 | pages = 103–110 | date = July 2011 | pmid = 21669892 | doi = 10.1542/peds.2010-3000 | doi-access = free }}</ref> It is not clear if co-sleeping among mothers who breastfeed without any other risk factors increases SIDS risk.<ref>{{cite journal | vauthors = Fleming PJ, Blair PS | title = Making informed choices on co-sleeping with your baby | journal = BMJ | volume = 350 | pages = h563 | date = February 2015 | pmid = 25643704 | doi = 10.1136/bmj.h563 | s2cid = 27309256 }}</ref>

===Pregnancy and infant factors===
SIDS rates decrease with increasing maternal age, with [[teenage pregnancy|teenage mothers]] at greatest risk.<ref name="sullivan">{{cite journal | vauthors = Sullivan FM, Barlow SM | title = Review of risk factors for sudden infant death syndrome | journal = Paediatric and Perinatal Epidemiology | volume = 15 | issue = 2 | pages = 144–200 | date = April 2001 | pmid = 11383580 | doi = 10.1046/j.1365-3016.2001.00330.x }}</ref> Delayed or inadequate [[prenatal care]] also increases risk.<ref name="sullivan"/> Low [[birth weight]] is a significant risk factor. In the United States from 1995 to 1998, the SIDS death rate for infants weighing 1000–1499 g was 2.89/1000, while for a birth weight of 3500–3999 g, it was only 0.51/1000.<ref name=wonder /><ref>{{cite journal | vauthors = Hunt CE | title = Small for gestational age infants and sudden infant death syndrome: a confluence of complex conditions | journal = Archives of Disease in Childhood. Fetal and Neonatal Edition | volume = 92 | issue = 6 | pages = F428–F429 | date = November 2007 | pmid = 17951549 | pmc = 2675383 | doi = 10.1136/adc.2006.112243 }}</ref> [[Premature birth]] increases the risk of SIDS death roughly fourfold.<ref name="sullivan"/><ref name="wonder"/> From 1995 to 1998, the U.S. SIDS rate for births at 37–39 weeks of [[gestation]] was 0.73/1000, while the SIDS rate for births at 28–31 weeks of gestation was 2.39/1000.<ref name="wonder"/>

[[Anemia]] has also been linked to SIDS<ref>{{cite journal | vauthors = Poets CF, Samuels MP, Wardrop CA, Picton-Jones E, Southall DP | title = Reduced haemoglobin levels in infants presenting with apparent life-threatening events--a retrospective investigation | journal = Acta Paediatrica | volume = 81 | issue = 4 | pages = 319–321 | date = April 1992 | pmid = 1606392 | doi = 10.1111/j.1651-2227.1992.tb12234.x | s2cid = 33298390 }}</ref> (however, per item 6 in the list of epidemiologic characteristics below, the extent of anemia cannot be evaluated at autopsy because an infant's total [[hemoglobin]] can only be measured during life).<ref>{{cite journal | vauthors = Giulian GG, Gilbert EF, Moss RL | title = Elevated fetal hemoglobin levels in sudden infant death syndrome | journal = The New England Journal of Medicine | volume = 316 | issue = 18 | pages = 1122–1126 | date = April 1987 | pmid = 2437454 | doi = 10.1056/NEJM198704303161804 }}</ref> SIDS incidence rises from zero at birth, is highest from two to four months of age, and declines toward zero after the infant's first year.<ref>{{cite journal | vauthors = Mage DT |title=A probability model for the age distribution of SIDS |journal=J Sudden Infant Death Syndrome Infant Mortal |volume=1 |pages=13–31 |year=1996}}</ref>

===Genetics===
[[Genetics]] plays a role, as SIDS is more prevalent in males.<ref name="wonderANDwho">See [http://wonder.cdc.gov CDC WONDER online database] {{webarchive|url=https://web.archive.org/web/20100424201355/http://wonder.cdc.gov/ |date=2010-04-24 }} and {{cite web |url=http://www3.who.int/whosis/menu.cfm?path=whosis,inds,mort&language=english |title=WHO Mortality Database |date=23 November 2001 |publisher=[[World Health Organization]] |access-date=2006-03-18 |archive-url=https://web.archive.org/web/20040627063703/http://www3.who.int/whosis/menu.cfm?path=whosis,inds,mort&language=english |archive-date=2004-06-27 }} for data on SIDS by gender in the US and throughout the world.</ref><ref name="Mage DT, Donner EM 2004 1210–5">{{cite journal | vauthors = Mage DT, Donner EM | title = The fifty percent male excess of infant respiratory mortality | journal = Acta Paediatrica | volume = 93 | issue = 9 | pages = 1210–1215 | date = September 2004 | pmid = 15384886 | doi = 10.1080/08035250410031305 }}</ref>  There is a consistent 50% male excess in SIDS per 1000 live births of each sex. Given a 5% male excess birth rate, there appears to be 3.15 male SIDS cases per 2 female cases, for a male fraction of 0.61.<ref name="wonderANDwho"/><ref name="Mage DT, Donner EM 2004 1210–5"/> This value of 61% in the US is an average of 57% black male SIDS, 62.2% white male SIDS, and 59.4% for all other races combined. Note that when multiracial parentage is involved, the infant's race is arbitrarily assigned to one category or the other; most often, it is chosen by the mother. The [[sex linkage|X-linkage]] hypothesis for SIDS and the male excess in infant mortality have shown that the 50% male excess might be related to a dominant X-linked [[allele]], occurring with a frequency of {{Frac|1|3}} that is protective against [[Cerebral hypoxia|transient cerebral anoxia]]. An unprotected male would occur with a frequency of {{Frac|2|3}} and an unprotected female would occur with a frequency of {{Frac|4|9}}.

About 10 to 20% of SIDS cases are believed to be due to [[channelopathies]], which are inherited defects in the [[ion channels]] that play an important role in the contraction of the heart.<ref>{{cite journal | vauthors = Behere SP, Weindling SN | title = Inherited arrhythmias: The cardiac channelopathies | journal = Annals of Pediatric Cardiology | volume = 8 | issue = 3 | pages = 210–220 | date = 2014 | pmid = 26556967 | pmc = 4608198 | doi = 10.4103/0974-2069.164695 | doi-access = free }}</ref>

Genetic evidence published in November 2020 concerning the case of [[Kathleen Folbigg]], who was imprisoned for the death of her children, showed that at least two of the children had genetic mutations in the [[CALM2]] gene that predisposed them to heart complications.<ref>{{Cite web | vauthors = de Vinuesa CG |title=Kathleen Folbigg's children likely died of natural causes, not murder. Here's the evidence my team found |url=http://theconversation.com/kathleen-folbiggs-children-likely-died-of-natural-causes-not-murder-heres-the-evidence-my-team-found-156487 |access-date=2021-12-16 |website=The Conversation |date=4 March 2021 |language=en |archive-date=4 March 2021 |archive-url=https://web.archive.org/web/20210304085909/http://theconversation.com/kathleen-folbiggs-children-likely-died-of-natural-causes-not-murder-heres-the-evidence-my-team-found-156487 |url-status=live }}</ref> Kathleen was pardoned 5 June 2023 after spending 20 years in jail.<ref>{{Cite news | vauthors = Rose T |date=2023-06-05 |title=Kathleen Folbigg pardoned and released after 20 years in jail over deaths of her four children |language=en-GB |work=The Guardian |url=https://www.theguardian.com/australia-news/2023/jun/05/kathleen-folbigg-pardoned-after-20-years-in-jail-over-deaths-of-her-four-children |access-date=2023-06-05 |issn=0261-3077}}</ref>

===Alcohol===
Drinking of alcohol by parents is linked to SIDS.<ref>{{cite journal | vauthors = Van Nguyen JM, Abenhaim HA | title = Sudden infant death syndrome: review for the obstetric care provider | journal = American Journal of Perinatology | volume = 30 | issue = 9 | pages = 703–714 | date = October 2013 | pmid = 23292938 | doi = 10.1055/s-0032-1331035 | s2cid = 25034518 }}</ref> One study found a positive correlation between the two during New Years celebrations and weekends.<ref>{{cite journal | vauthors = Phillips DP, Brewer KM, Wadensweiler P | title = Alcohol as a risk factor for sudden infant death syndrome (SIDS) | journal = Addiction | volume = 106 | issue = 3 | pages = 516–525 | date = March 2011 | pmid = 21059188 | doi = 10.1111/j.1360-0443.2010.03199.x | url = https://zenodo.org/record/886389 | access-date = 6 September 2017 | url-status = live | archive-url = https://web.archive.org/web/20170906181709/https://zenodo.org/record/886389 | archive-date = 6 September 2017 }}</ref> Another found that [[alcohol use disorder]] was linked to a more than doubling of risk.<ref>{{cite journal | vauthors = O'Leary CM, Jacoby PJ, Bartu A, D'Antoine H, Bower C | title = Maternal alcohol use and sudden infant death syndrome and infant mortality excluding SIDS | journal = Pediatrics | volume = 131 | issue = 3 | pages = e770–e778 | date = March 2013 | pmid = 23439895 | doi = 10.1542/peds.2012-1907 | s2cid = 2523083 }}</ref>

===Other===
A 2022 study found that infants who died of SIDS exhibited significantly lower specific activity of [[butyrylcholinesterase]], an enzyme involved in the brain's arousal pathway, shortly after birth. This can serve as a [[Biomarker (medicine)|biomarker]] to identify infants with a potential [[Autonomic nervous system|autonomic]] [[cholinergic]] dysfunction and elevated risk for SIDS.<ref>{{cite journal | vauthors = Harrington CT, Hafid NA, Waters KA | title = Butyrylcholinesterase is a potential biomarker for Sudden Infant Death Syndrome | journal = eBioMedicine | volume = 80 | pages = 104041 | date = June 2022 | pmid = 35533499 | pmc = 9092508 | doi = 10.1016/j.ebiom.2022.104041 | s2cid = 248645079 }}</ref><ref>{{Cite web |title=Researchers Pinpoint Reason Infants Die From SIDS |url=https://www.biospace.com/article/researchers-answer-how-and-why-infants-die-from-sids/ |access-date=2022-05-12 |website=BioSpace |language=en-US |archive-date=10 May 2022 |archive-url=https://web.archive.org/web/20220510182628/https://www.biospace.com/article/researchers-answer-how-and-why-infants-die-from-sids/ |url-status=live }}</ref><ref>{{cite news |title=Groundbreaking New Study Finds Possible Explanation for SIDS |url=https://www.goodnewsnetwork.org/groundbreaking-new-study-finds-possible-explanation-for-sids/ |agency=Goods News Network |publisher=Goods News Network |date=May 17, 2022 |access-date=20 May 2022 |archive-date=22 May 2022 |archive-url=https://web.archive.org/web/20220522123206/https://www.goodnewsnetwork.org/groundbreaking-new-study-finds-possible-explanation-for-sids/ |url-status=live }}</ref>

SIDS has been linked to cold weather, with this association believed to be due to over-bundling and thus, overheating.<ref>{{cite web |title=NIH alerts caregivers to increase in SIDS risk during cold weather |url=https://www.nih.gov/news-events/news-releases/nih-alerts-caregivers-increase-sids-risk-during-cold-weather |website=National Institutes of Health (NIH) |access-date=27 July 2018 |language=en |date=3 September 2015 |archive-date=10 April 2019 |archive-url=https://web.archive.org/web/20190410154310/https://www.nih.gov/news-events/news-releases/nih-alerts-caregivers-increase-sids-risk-during-cold-weather |url-status=live }}</ref> Premature babies are at four times the risk of SIDS, possibly related to an underdeveloped ability to automatically control the cardiovascular system.<ref>{{cite journal | vauthors = Horne RS | title = Effects of prematurity on heart rate control: implications for sudden infant death syndrome | journal = Expert Review of Cardiovascular Therapy | volume = 4 | issue = 3 | pages = 335–343 | date = May 2006 | pmid = 16716094 | doi = 10.1586/14779072.4.3.335 | s2cid = 26689292 }}</ref>

A 2-part edition of ''[[The Cook Report]]'' from 1994 claimed that antimony- and phosphorus-containing compounds used as fire retardants in [[PVC]] and other cot mattress materials were a cause of SIDS. Subsequent investigation by an Expert Panel led by Lady Limerick found that there was no evidence to support this claim.<ref>See [https://web.archive.org/web/20001026033455/http://www.sids.org.uk/fsid/limerick.htm FSID Press release].</ref> The report also states that toxic gas cannot be generated from antimony in mattresses and that babies had SIDS on mattresses that did not contain the compound.

It has been suggested that some cases of SIDS may be related to ''[[Staphylococcus aureus]]'' and ''[[Escherichia coli]]'' infections.<ref>{{cite journal | vauthors = Weber MA, Klein NJ, Hartley JC, Lock PE, Malone M, Sebire NJ | title = Infection and sudden unexpected death in infancy: a systematic retrospective case review | journal = Lancet | volume = 371 | issue = 9627 | pages = 1848–1853 | date = May 2008 | pmid = 18514728 | doi = 10.1016/S0140-6736(08)60798-9 | s2cid = 8017934 }}</ref>

==Diagnosis==
===Differential diagnosis===
Some conditions that are often undiagnosed and could be confused with or [[comorbidity|comorbid]] with SIDS include:
* [[medium-chain acyl-coenzyme A dehydrogenase deficiency]] (MCAD deficiency);<ref>{{cite journal | vauthors = Yang Z, Lantz PE, Ibdah JA | title = Post-mortem analysis for two prevalent beta-oxidation mutations in sudden infant death | journal = Pediatrics International | volume = 49 | issue = 6 | pages = 883–887 | date = December 2007 | pmid = 18045290 | doi = 10.1111/j.1442-200X.2007.02478.x | s2cid = 25455710 | doi-access = free }}</ref>
* infant [[botulism]];<ref>{{cite journal | vauthors = Nevas M, Lindström M, Virtanen A, Hielm S, Kuusi M, Arnon SS, Vuori E, Korkeala H | display-authors = 6 | title = Infant botulism acquired from household dust presenting as sudden infant death syndrome | journal = Journal of Clinical Microbiology | volume = 43 | issue = 1 | pages = 511–513 | date = January 2005 | pmid = 15635031 | pmc = 540168 | doi = 10.1128/JCM.43.1.511-513.2005 }}</ref>
* [[long QT syndrome]] (accounting for less than 2% of cases);<ref>{{cite journal | vauthors = Millat G, Kugener B, Chevalier P, Chahine M, Huang H, Malicier D, Rodriguez-Lafrasse C, Rousson R | display-authors = 6 | title = Contribution of long-QT syndrome genetic variants in sudden infant death syndrome | journal = Pediatric Cardiology | volume = 30 | issue = 4 | pages = 502–509 | date = May 2009 | pmid = 19322600 | doi = 10.1007/s00246-009-9417-2 | s2cid = 7473579 }}</ref>
* ''[[Helicobacter pylori]]'' bacterial infections;<ref>{{cite journal | vauthors = Stray-Pedersen A, Vege A, Rognum TO | title = Helicobacter pylori antigen in stool is associated with SIDS and sudden infant deaths due to infectious disease | journal = Pediatric Research | volume = 64 | issue = 4 | pages = 405–410 | date = October 2008 | pmid = 18535491 | doi = 10.1203/PDR.0b013e31818095f7 | doi-access = free }}</ref>
* [[shaken baby syndrome]] and other forms of [[child abuse]];<ref>{{cite journal | vauthors = Bajanowski T, Vennemann M, Bohnert M, Rauch E, Brinkmann B, Mitchell EA | title = Unnatural causes of sudden unexpected deaths initially thought to be sudden infant death syndrome | journal = International Journal of Legal Medicine | volume = 119 | issue = 4 | pages = 213–216 | date = July 2005 | pmid = 15830244 | doi = 10.1007/s00414-005-0538-8 | s2cid = 34327548 }}</ref><ref>{{cite journal | vauthors = Du Chesne A, Bajanowski T, Brinkmann B | title = [Homicides without clues in children] | language = de | journal = Archiv für Kriminologie | volume = 199 | issue = 1–2 | pages = 21–26 | year = 1997 | pmid = 9157833 }}</ref>
*[[overlaying]], child smothering during carer's sleep<ref>{{cite journal | vauthors = Williams FL, Lang GA, Mage DT | title = Sudden unexpected infant deaths in Dundee, 1882-1891: overlying or SIDS? | journal = Scottish Medical Journal | volume = 46 | issue = 2 | pages = 43–47 | date = April 2001 | pmid = 11394337 | doi = 10.1177/003693300104600206 | s2cid = 29612195 }}</ref>

For example, an infant with MCAD deficiency might die by "classical SIDS" if found [[swaddling|swaddled]] and [[prone]], with its head covered, in an overheated room where [[smoking and pregnancy|parents were smoking]]. Genes indicating susceptibility to MCAD and Long QT syndrome do not protect an infant from dying of classical SIDS. Therefore, the presence of a susceptibility gene, such as for MCAD, means the infant might have died either from SIDS or from MCAD deficiency. It is currently impossible for a pathologist to distinguish between them.

A 2010 study looked at 554 autopsies of infants in [[North Carolina]] that listed SIDS as the cause of death and suggested that many of these deaths may have been due to accidental suffocation.  The study found that 69% of autopsies listed other possible risk factors that could have led to death, such as unsafe bedding or sleeping with adults.<ref>{{cite web |url=http://www.charlotteobserver.com/sids/ |title=Cradle of Secrets |website=CharlotteObserver.com |access-date=2011-07-20 |url-status=dead |archive-url=https://web.archive.org/web/20110811030214/http://www.charlotteobserver.com/sids/ |archive-date=2011-08-11 }}</ref>

Several instances of [[infanticide]] have been uncovered in which the diagnosis was originally SIDS.<ref name="Glatt 2000">{{cite book |title=Cradle of Death: A Shocking True Story of a Mother, Multiple Murder, and SIDS |year=2000 |isbn=978-0-312-97302-5 | vauthors = Glatt J |publisher=Macmillan}}</ref><ref name="Havill 2002">{{cite book |title=While Innocents Slept: A Story of Revenge, Murder, and SIDS |year=2002 |isbn=978-0-312-97517-3 | vauthors = Havill A |publisher=Macmillan}}</ref> Since an autopsy is often unable to determine whether asphyxiation is caused intentionally, medical practitioners rely on patient and family history and evidence of prior abuse to identify cases of infanticide.<ref name="pediatrics-hymel"/> Some estimates in the 1980s and 1990s placed the potential rate of SIDS deaths caused by maltreatment around 10% and as high as 40%, but data from interventions such as the [[Safe to Sleep]] campaign suggest that these figures were substantially inflated.<ref name="afp-milroy"/> In 2006, the [[American Academy of Pediatrics]] estimated that between 1% and 5% of SIDS cases were potentially attributable to undiagnosed infanticide.<ref name="pediatrics-hymel"/>

Some have underestimated the risk of two SIDS deaths occurring in the same family; the [[Royal Statistical Society]] issued a media release refuting expert testimony in one UK case, in which the conviction was subsequently overturned.<ref>[http://www.rss.org.uk/main.asp?pages =1225 "About Statistics and the Law"] {{Webarchive|url=https://web.archive.org/web/20070902044706/http://www.rss.org.uk/main.asp?pages |date=2 September 2007 }} (Website). Royal Statistical Society. (2001-10-23) Retrieved on 2007-09-22</ref>

==Prevention==
Several measures are effective in preventing SIDS, including changing the sleeping position to [[Supine position|supine]], breastfeeding, limiting soft bedding, immunizing the infant, and using pacifiers.<ref name=Moon2012/><ref>{{cite web | url = https://www.healthychildren.org/English/ages-stages/baby/sleep/Pages/Preventing-SIDS.aspx | title = Reduce the Risk of SIDS & Suffocation - AAP general recommendations | year = 2017| publisher = [[Healthy Children]] | archive-url = https://archive.today/20091213034359/https://www.healthychildren.org/English/ages-stages/baby/sleep/Pages/Preventing-SIDS.aspx | archive-date = December 13, 2009 | url-status = live}}</ref> The use of electronic monitors is not useful as a preventative strategy.<ref name=Moon2012/> The effect that fans might have on the risk of SIDS has not been studied well enough to make any recommendation about them.<ref name=Moon2012/> Evidence regarding swaddling is unclear regarding SIDS.<ref name=Moon2012/> A 2016 review found tentative evidence that swaddling increases the risk of SIDS, especially among babies placed on their bellies or sides while sleeping.<ref>{{cite journal | vauthors = Pease AS, Fleming PJ, Hauck FR, Moon RY, Horne RS, L'Hoir MP, Ponsonby AL, Blair PS | display-authors = 6 | title = Swaddling and the Risk of Sudden Infant Death Syndrome: A Meta-analysis | journal = Pediatrics | volume = 137 | issue = 6 | pages = e20153275 | date = June 2016 | pmid = 27244847 | doi = 10.1542/peds.2015-3275 | quote = Limited evidence suggested swaddling risk increased with infant age and was associated with a twofold risk for infants aged >6 months. | doi-access = free }}</ref>

Measures not shown to be useful include positioning devices and [[baby monitors]].<ref name=Moon2012/><ref name=NIH2014Pre/> In the United States, companies that sell the monitors do not have [[United States Food and Drug Administration|FDA]] approval for them as medical devices.<ref name="pmid28118463">{{cite journal | vauthors = Bonafide CP, Jamison DT, Foglia EE | title = The Emerging Market of Smartphone-Integrated Infant Physiologic Monitors | journal = JAMA | volume = 317 | issue = 4 | pages = 353–354 | date = January 2017 | pmid = 28118463 | pmc = 5310844 | doi = 10.1001/jama.2016.19137 }}</ref>

===Sleep positioning===

[[File:back to sleep plot.png|thumb|upright=1.4|SIDS rate from 1988 to 2006 (U.S.)]]

Sleeping on the back has been found to reduce the risk of SIDS.<ref name=Mitch2009>{{cite journal | vauthors = Mitchell EA | title = SIDS: past, present and future | journal = Acta Paediatrica | volume = 98 | issue = 11 | pages = 1712–1719 | date = November 2009 | pmid = 19807704 | doi = 10.1111/j.1651-2227.2009.01503.x | s2cid = 1566087 }}</ref> It is thus recommended by the [[American Academy of Pediatrics]] and promoted as a best practice by the US [[National Institute of Child Health and Human Development]] (NICHD) "[[Safe to Sleep]]" campaign. The incidence of SIDS has fallen in a number of countries in which this recommendation has been widely adopted.<ref>{{cite journal | vauthors = Mitchell EA, Hutchison L, Stewart AW | title = The continuing decline in SIDS mortality | journal = Archives of Disease in Childhood | volume = 92 | issue = 7 | pages = 625–626 | date = July 2007 | pmid = 17405855 | pmc = 2083749 | doi = 10.1136/adc.2007.116194 }}</ref> Sleeping on the back does not appear to increase the risk of choking, even in those with [[gastroesophageal reflux disease]].<ref name=Moon2012/> While infants in this position may sleep more lightly, this is not harmful.<ref name=Moon2012/> Sharing the same room as the parents but in a different bed may decrease the SIDS risk by half.<ref name=Moon2012/>

===Pacifiers===
The use of [[pacifier]]s appears to decrease the risk of SIDS,{{quantify|date=July 2022}} although the reason is unclear.<ref name=Moon2012/> The [[American Academy of Pediatrics]] considers pacifier use to prevent SIDS to be reasonable.<ref name=Moon2012/> Pacifiers do not appear to affect breastfeeding in the first four months, even though this is a common misconception.<ref>{{cite journal | vauthors = Jaafar SH, Ho JJ, Jahanfar S, Angolkar M | title = Effect of restricted pacifier use in breastfeeding term infants for increasing duration of breastfeeding | journal = The Cochrane Database of Systematic Reviews | volume = 2016 | issue = 8 | pages = CD007202 | date = August 2016 | pmid = 27572944 | pmc = 8520760 | doi = 10.1002/14651858.CD007202.pub4 }}</ref>

===Bedding===
Product safety experts advise against using pillows, overly soft mattresses, sleep positioners, bumper pads (crib bumpers), stuffed animals, or fluffy bedding in the crib, and recommend instead dressing the child warmly and keeping the crib "naked."<ref>{{cite web  |title=What Can Be Done?  |publisher=American SIDS Institute  |url=http://www.sids.org/nprevent.htm  |url-status=dead  |archive-url=https://web.archive.org/web/20030621224728/http://www.sids.org/nprevent.htm  |archive-date=2003-06-21  }}</ref>

Due to the obvious dangers, experts have also warned that blankets or other clothing should not be placed over a baby's head.<ref name=AAP2016Guid>{{cite journal | vauthors = Moon RY, Darnall RA, Feldman-Winter L, Goodstein MH, Hauck FR | collaboration = Task Force on Sudden Infant Death Syndrome | title = SIDS and Other Sleep-Related Infant Deaths: Updated 2016 Recommendations for a Safe Infant Sleeping Environment | journal = Pediatrics | volume = 138 | issue = 5 | pages = e20162938 | date = November 2016 | pmid = 27940804 | doi = 10.1542/peds.2016-2938 | doi-access = free }}</ref>

The use of a "[[Sleeping bag#Infant use|baby sleep bag]]" or "sleep sack", a soft bag with holes for the baby's arms and head, can be used as a type of bedding that warms the baby without covering its head.<ref name="aap_sacks">{{cite web |title=The Changing Concept of Sudden Infant Death Syndrome: Diagnostic Coding Shifts, Controversies Regarding the Sleeping Environment, and New Variables to Consider in Reducing Risk |publisher=[[American Academy of Pediatrics]] |access-date=2008-11-06 |url=http://aappolicy.aappublications.org/cgi/content/full/pediatrics;116/5/1245#SEC15 |url-status=dead |archive-url=https://web.archive.org/web/20081203234922/http://aappolicy.aappublications.org/cgi/content/full/pediatrics%3B116/5/1245#SEC15 |archive-date=3 December 2008 }}</ref>

===Vaccination===

Infants typically receive several vaccinations between the ages of 2 and 4 months, which is also the peak age for SIDS. Due to this coincidence, a number of studies have investigated the possible role of vaccinations as a cause of SIDS. These have found either no relation between vaccinations and SIDS, or a reduction of the risk of SIDS following vaccination.<ref>{{cite journal | vauthors = Müller-Nordhorn J, Hettler-Chen CM, Keil T, Muckelbauer R | title = Association between sudden infant death syndrome and diphtheria-tetanus-pertussis immunisation: an ecological study | journal = BMC Pediatrics | volume = 15 | issue = 1 | pages = 1 | date = January 2015 | pmid = 25626628 | pmc = 4326294 | doi = 10.1186/s12887-015-0318-7 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Mitchell EA, Stewart AW, Clements M | title = Immunisation and the sudden infant death syndrome. New Zealand Cot Death Study Group | journal = Archives of Disease in Childhood | volume = 73 | issue = 6 | pages = 498–501 | date = December 1995 | pmid = 8546503 | pmc = 1511439 | doi = 10.1136/adc.73.6.498 }}</ref><ref>{{cite journal | vauthors = Fleming PJ, Blair PS, Platt MW, Tripp J, Smith IJ, Golding J | title = The UK accelerated immunisation programme and sudden unexpected death in infancy: case-control study | journal = BMJ | volume = 322 | issue = 7290 | pages = 822 | date = April 2001 | pmid = 11290634 | pmc = 30557 | doi = 10.1136/bmj.322.7290.822 }}</ref><ref name="Do immunisations reduce the risk fo"/><ref>{{cite journal | vauthors = Hoffman HJ, Hunter JC, Damus K, Pakter J, Peterson DR, van Belle G, Hasselmeyer EG | title = Diphtheria-tetanus-pertussis immunization and sudden infant death: results of the National Institute of Child Health and Human Development Cooperative Epidemiological Study of Sudden Infant Death Syndrome risk factors | journal = Pediatrics | volume = 79 | issue = 4 | pages = 598–611 | date = April 1987 | pmid = 3493477 | doi = 10.1542/peds.79.4.598 | s2cid = 37163477 }}</ref><ref>{{cite journal | vauthors = Carvajal A, Caro-Patón T, Martín de Diego I, Martín Arias LH, Alvarez Requejo A, Lobato A | title = [DTP vaccine and infant sudden death syndrome. Meta-analysis] | journal = Medicina Clinica | volume = 106 | issue = 17 | pages = 649–652 | date = May 1996 | pmid = 8691909 }}</ref> A 2007 meta-analysis found that vaccinations were associated with a halving of the risk of SIDS, and argued that immunisation should be a part of SIDS prevention campaigns.<ref name="Do immunisations reduce the risk fo">{{cite journal | vauthors = Vennemann MM, Höffgen M, Bajanowski T, Hense HW, Mitchell EA | title = Do immunisations reduce the risk for SIDS? A meta-analysis | journal = Vaccine | volume = 25 | issue = 26 | pages = 4875–4879 | date = June 2007 | pmid = 17400342 | doi = 10.1016/j.vaccine.2007.02.077 }}</ref><ref name="CDCFAQ">{{cite web |title=Vaccine Safety: Common Concerns: Sudden Infant Death Syndrome (SIDS) |url=https://www.cdc.gov/vaccinesafety/Concerns/sids.html |publisher=[[Centers for Disease Control and Prevention]] |date=28 August 2015 |access-date=15 April 2016 |url-status=live |archive-url=https://web.archive.org/web/20160417194809/http://www.cdc.gov/vaccinesafety/concerns/sids.html |archive-date=17 April 2016 }}</ref>

==Epidemiology==
[[File:The art of nursing- or Fleuron T080702-1.png|thumb|Arcutio, a device designed to prevent infant death by suffocation, ''Philosophical Transactions'' 422 (1732)]]
Globally, SIDS resulted in about 22,000 deaths {{as of|2010|lc=y}}, down from 30,000 deaths in 1990.<ref name=Loz2012>{{cite journal | vauthors = Lozano R, Naghavi M, Foreman K, Lim S, Shibuya K, Aboyans V, etal | title = Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010 | journal = Lancet | volume = 380 | issue = 9859 | pages = 2095–2128 | date = December 2012 | pmid = 23245604 | pmc = 10790329 | doi = 10.1016/S0140-6736(12)61728-0 | url = https://zenodo.org/record/2557786 | access-date = 18 September 2020 | url-status = live | hdl-access = free | s2cid = 1541253 | archive-date = 19 May 2020 | archive-url = https://web.archive.org/web/20200519152712/https://zenodo.org/record/2557786 | hdl = 10536/DRO/DU:30050819 }}</ref> Rates vary significantly by population from 0.05 per 1000 in Hong Kong to 6.7 per 1000 in Native Americans.<ref>{{cite journal | vauthors = Sharma BR | title = Sudden infant death syndrome: a subject of medicolegal research | journal = The American Journal of Forensic Medicine and Pathology | volume = 28 | issue = 1 | pages = 69–72 | date = March 2007 | pmid = 17325469 | doi = 10.1097/01.paf.0000220934.18700.ef | url = http://adc.bmj.com/cgi/content/short/46/248/579-a | access-date = 14 February 2019 | url-status = live | s2cid = 37925269 | archive-url = https://web.archive.org/web/20210829073529/https://adc.bmj.com/content/46/248/579.2 | archive-date = 29 August 2021 | url-access = subscription }}</ref>

SIDS was responsible for 0.54 deaths per 1,000 live births in the US in 2005.<ref name=wonder>{{cite web |url=http://wonder.cdc.gov |title=Cdc Wonder |publisher=Centers for Disease Control and Prevention (CDC) |date=2010-02-24 |access-date=2010-04-17 |url-status=live |archive-url=https://web.archive.org/web/20100424201355/http://wonder.cdc.gov/ |archive-date=2010-04-24 }}</ref> It is responsible for far fewer deaths than [[congenital disorder]]s and [[premature birth|disorders related to short gestation]], though it is the leading cause of death in healthy infants after one month of age.

SIDS deaths in the US decreased from 4,895 in 1992 to 2,247 in 2004, a 54% decrease.<ref name=Bowman07>{{cite web | vauthors = Bowman L, Hargrove T |title=Saving babies: Exposing Sudden Infant Death In America |work=DailyCamera.com |url=http://dailycamera.com/news/2007/oct/08/saving-babies-exposing-sudden-infant-death-in/ |access-date=2008-09-30 |url-status=dead |archive-url=https://web.archive.org/web/20090226153439/http://www.dailycamera.com/news/2007/oct/08/saving-babies-exposing-sudden-infant-death-in/ |archive-date=2009-02-26 }}</ref> During a similar time period, 1989 to 2004, SIDS as the cause of death for sudden infant death (SID) decreased from 80% to 55%, a 31% decrease.<ref name=Bowman07/> According to John Kattwinkel, chairman of the Centers for Disease Control and Prevention (CDC) Special Task Force on SIDS "A lot of us are concerned that the rate (of SIDS) isn't decreasing significantly, but that a lot of it is just [[diagnosis code|code]] shifting".<ref name=Bowman07/>

===Race===

[[File:US SIDS rates race 2009.png|thumb|upright=1.4|Rates of SIDS by race/ethnicity in the U.S., 2009, CDC, 2013]]

In 2013, there were persistent disparities in SIDS deaths among racial and ethnic groups in the U.S. In 2009, the rates of death ranged from 20.3 per 100,000 live births for Asians and Pacific Islanders to 119.2 per 100,000 live births for Native Americans and Alaska Natives. African American infants have a 24% greater risk (100.7 per 100,000 live births) of having a SIDS-related death, compared to the U.S. population as a whole,<ref>{{cite journal| vauthors = Powers DA, Song S |title=Absolute change in cause-specific infant mortality for blacks and whites in the US: 1983–2002|journal=Tion Research and Policy Review|date=2009|volume=28|issue=6|pages=817–851|doi=10.1007/s11113-009-9130-0|s2cid=72279012}}</ref> and experience a 2.5{{Vague|reason=It is unclear if the given quantity represents a fold increase or a percent increase|date=October 2024}} greater incidence of SIDS than white infants.<ref>{{cite journal | vauthors = Pollack HA, Frohna JG | title = A competing risk model of sudden infant death syndrome incidence in two US birth cohorts | journal = The Journal of Pediatrics | volume = 138 | issue = 5 | pages = 661–667 | date = May 2001 | pmid = 11343040 | doi = 10.1067/mpd.2001.112248 }}</ref> Rates are calculated per 100,000 live births to enable more accurate comparison across groups of different total population sizes.

Research suggests that factors that contribute more directly to SIDS risk—maternal age, exposure to smoking, safe sleep practices, etc.—vary by racial and ethnic group, and therefore risk exposure also varies by these groups.<ref name=Kin2009/> Risk factors associated with prone sleeping patterns of African American families include the mother's age, household poverty index, rural/urban status of residence, and infant's age. More than 50% of African American infants were placed in non-recommended sleeping positions, according to a 2012  study completed in South Carolina,<ref>{{cite journal | vauthors = Smith MG, Liu JH, Helms KH, Wilkerson KL | title = Racial differences in trends and predictors of infant sleep positioning in South Carolina, 1996-2007 | journal = Maternal and Child Health Journal | volume = 16 | issue = 1 | pages = 72–82 | date = January 2012 | pmid = 21165764 | doi = 10.1007/s10995-010-0718-0 | s2cid = 2668964 }}</ref> indicating that cultural factors can be protective as well as problematic.<ref>{{cite book| vauthors = Brathwaite-Fisher T, Bronheim A |title=Cultural Competence and Sudden Infant Death Syndrome and Other Infant Death: A Review of the Literature from 1990–2000|publisher=National Center for Cultural Competence, Georgetown University Center for Child and Human Development |year=2001 |url=http://gucchd.georgetown.edu/products/SIDS_LiteratureReview.doc |format=DOC|access-date=2013-09-29 |url-status=dead |archive-url=https://web.archive.org/web/20100612094521/http://gucchd.georgetown.edu/products/SIDS_LiteratureReview.doc |archive-date=2010-06-12 |df=ymd-all}}</ref>

The rate of SIDS per 1000 births varies among ethnic groups in the United States:<ref name=Moon2007/><ref>{{cite web| vauthors = Burnett LB |title=Sudden Infant Death Syndrome|url=http://emedicine.medscape.com/article/804412-overview#a6|website=Medscape|url-status=live|archive-url=https://web.archive.org/web/20160801153511/http://emedicine.medscape.com/article/804412-overview#a6|archive-date=2016-08-01|date=20 October 2019}}</ref>
*Central Americans and South Americans: 0.20
*Asian/Pacific Islanders: 0.28
*Mexicans: 0.24
*Puerto Ricans: 0.53
*Whites: 0.51
*African Americans: 1.08
*Native American: 1.24

==Society and culture==
{{Expand section|date=November 2020}}

Many popular media portrayals of infants show them in non-recommended sleeping positions.<ref name="Moon2012" />

== See also ==
{{Portal|Medicine}}
* [[Fading puppy syndrome]]
* [[Failure to thrive]]
* [[Neonatal isoerythrolysis]]
* [[Newborn care and safety]]
* [[Sudden unexpected death syndrome]]
* [[Sudden unexplained death in childhood]]
* [[Sudden unexpected death in epilepsy]]

== References ==
{{Reflist}}

== Further reading ==
{{Refbegin}}
* {{Cite book |vauthors=[[Joan Hodgman|Hodgman J]], Hoppenbrouwers T |year=2004 |title=SIDS |location=Calabasas, Calif. |publisher=Monte Nido Press |isbn=978-0-9742663-0-5}}
* {{Cite journal |vauthors=Lewak N |year=2004 |title=Book Review: SIDS |url=http://archpedi.highwire.org/cgi/content/full/158/4/405 |doi=10.1001/archpedi.158.4.405 |url-status=dead |archive-url=https://web.archive.org/web/20081017135640/http://archpedi.highwire.org/cgi/content/full/158/4/405 |archive-date=17 October 2008 |journal=Arch Pediatr Adolesc Med |volume=158 |issue=4 |pages=405 |df=dmy-all |url-access=subscription }}
* {{Cite book |vauthors=Ottaviani G |year=2014 |title=Crib Death – Sudden infant Death Syndrome (SIDS): Sudden Infant and Perinatal Unexplained Death: The Pathologist's Viewpoint |edition=2nd |location=Cham, Switzerland |publisher=Springer |isbn=9783319083469 |oclc=894851697}}
{{Refend}}

== External links ==
<!-- BEFORE inserting new links here you should first post it to the talk page, otherwise your edit is likely to be reverted. -->
{{Commons}}
* {{Cite web|title=Sudden Unexpected Infant Death and Sudden Infant Death Syndrome|url=https://www.cdc.gov/sids/data.htm|website=Data and Statistics|publisher=Center for Disease Control and Prevention|access-date=March 26, 2017}}
<!--===Scientific Studies=== In the refs-->

{{Medical resources
|DiseasesDB     = 12633
|ICD10          = {{ICD10|R|95||r|95}}
|ICD9           = {{ICD9|798.0}}
|ICDO           =
|OMIM           = 272120
|MedlinePlus    = 001566
|eMedicineSubj  = emerg
|eMedicineTopic = 407
|eMedicine_mult = {{eMedicine2|ped|2171}}
|MeshID         = D013398
}}
{{Infants and their care}}
{{Authority control}}

[[Category:Ailments of unknown cause]]
[[Category:Causes of death]]
[[Category:Infant mortality]]
[[Category:Sleep disorders]]
[[Category:Syndromes]]
[[Category:Wikipedia medicine articles ready to translate]]
[[Category:Causes of death specific to children]]