Sudden infant death syndrome

syndrome that is characterized by the sudden death of an infant that is not predicted by medical history and remains unexplained after a thorough forensic autopsy and detailed death scene investigation.

Sudden infant death syndrome (SIDS) is the sudden and unexpected death of a human baby which is unexplained even after an autopsy and investigation.[1][2] SIDS is sometimes referred to as cot death or crib death.

The name is only applied to cases where the baby is less than one year old. By definition, SIDS deaths occur under the age of one year. Most happen when the infant is 2 to 4 months of age. This is a critical period because the infant's ability to arouse from sleep is not yet mature.[3] SIDS is defined as a syndrome. It happens more often in Developing countries.

Babies are at the highest risk for SIDS during their sleep. Male infants die more often than female infants; about 60% of the cases are male infants. Infants also die more often during winter months.

The reason for SIDS are unknown, but there are different theories:

  • Problems with blood flow to the brain
  • Problems with levels of serotonin
  • Effects of the bacterium Clostridium botulinum (which causes botulism)
  • Toxic gases
  • Parents lacking education, so they do not wrap up the baby to sleep or lay them on their back

Vaccinations do not increase the risk of SIDS, and may reduce the risk slightly.[4][5]

Infanticide and child abuse cases may be misdiagnosed as SIDS due to lack of evidence. and caretakers of infants with SIDS are sometimes falsely accused.[6][7] Accidental suffocations are also sometimes misdiagnosed as SIDS and vice versa.[8] Grief support for families affected by SIDS is particularly important. The death of the infant is typically sudden, without witnesses, and requires an investigation.

A broader term, “sudden and unexpected infant death” (SUID) is used to describe all such deaths, regardless of cause. Cases of SUID that remain unexplained after a complete autopsy and review of the circumstances of death and clinical history are classified as SIDS. Thus, SIDS is one of the causes of SUID and accounts for 80% of such deaths.

Risk factors

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Nobody knows what causes SIDS. However, there are some known risk factors for SIDS.

Not every infant who has one of these risk factors dies from SIDS. Risk factors just make it more likely for a baby to have SIDS.

Tobacco smoke

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SIDS happens more in infants of mothers who smoke while they are pregnant.[9][10] The higher the levels of nicotine in the infant's blood, the higher the risk of SIDS.[11] Nicotine causes important changes in the way a fetus develops during pregnancy, which have been linked to SIDS as well as miscarriages.[12]

Sleeping

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Infants who are put to sleep on their stomachs or sides are more likely to die of SIDS.[13] This risk is highest in infants who are two to three months old.[13] The "Back to Sleep" movement has encouraged parents to put their infants to sleep on their backs to prevent SIDS.

Other things that increase the risk for SIDS while an infant is sleeping include:[14][15]

  • A hot or cold bedroom
  • Having many blankets in the infant's crib, or a lot of clothing on the infant
  • Soft sleeping surfaces
  • Having stuffed animals in the crib

Some researchers think these things can make it difficult for infants to control their body temperature, making them unable to control their breathing.[14]

Infants are more likely to die of SIDS if they share a bed with parents or older children.[16] This risk is highest:[13][17]

  • When the infant is less than three months old;
  • When the mattress is soft;
  • When one or more people share the infant's bed; and
  • When people in the bed are using drugs or alcohol, or are smoking.

The American Academy of Pediatrics says that if parents share a room with an infant without sharing a bed, they can cut their infant's risk of SIDS in half.[18]

Breastfeeding

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Infants who are breastfed are less likely to die of SIDS. The more an infant has been breastfed, the less likely they are to die of SIDS.[19]

Pregnancy and infant factors

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SIDS is less likely to happen in infants of older mothers. Infants of teenage mothers are at the highest risk.[9]

An infant is also at a higher risk of SIDS if:

SIDS only happens at certain ages. The risk of SIDS is highest in infants from two to four months old. After the infant reaches one year old, the risk decreases and then eventually reaches zero.[23]

Genetics

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Genetics affect the risk of SIDS. Baby boys have about a 50% higher risk of SIDS than baby girls.[24][25][26] Scientists think this might be because of an allele that exists on the X chromosome. They think this allele helps protect against episodes where the brain does not get enough oxygen (transient cerebral anoxia). Baby boys would be more likely to be missing this allele because they have XY chromosomes.

Scientists think that about 10 to 20% of SIDS cases are caused by inherited defects in the ion channels that help the heart squeeze out blood.[27]

The risk of SIDS seems to be affected by things like how much education an infant's mother got, race, ethnicity, and poverty.[28]

Vaccinations do not increase the risk of SIDS.[4][5] Most studies have shown that getting vaccinations cuts an infant's risk of a SIDS death in half.[29][30][31][32][33]

SIDS may be more common in babies with Staphylococcus aureus or Escherichia coli (E. coli) infections, but scientists are not sure.[34]

Preventing SIDS

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Sleep positioning

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Putting infants to sleep on their backs can help prevent SIDS.[35] The number of SIDS deaths has fallen in countries where this is commonly done.[36] Also, if parents share a room with their infant but do not share a bed, they can cut the risk of SIDS in half.[13]

Bedding

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Parents can help prevent SIDS by not using pillows, very soft mattresses, stuffed animals, or fluffy blankets in their infant's crib. Dressing the infant warmly and keeping the crib "naked" lowers the risk of SIDS.[37]

If an infant has a blanket in the crib, they should be covered only up to their chest, with their arms left outside the blanket. This makes it harder for the infant to move the blanket over their head, which could cause breathing problems.

In colder places where infants need help staying warm, the American Academy of Pediatrics suggests using a "sleep sack."[38] This is like a sleeping bag for a baby, but with holes for the baby's arms and head. The bag is closed around the baby with a zipper. This helps keep the baby warm without covering their head. Sleep sacks are especially helpful for babies with low birth weight, who have more trouble keeping themselves warm.[39]

Vaccination

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Many studies have shown that vaccines normally given to infants help prevent SIDS. For example, one very large research study showed that giving infants vaccines for diptheria, tetanus, and pertussis helps prevent SIDS.[40]

Getting normal infant vaccines cuts infants' risk of SIDS in half, according to many studies.[29][30][31][32][33]

References

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  1. Willinger M; James L.S. & Catz C. 1991. Defining the sudden infant death syndrome (SIDS). Deliberations of an expert panel convened by the National Institute of Child Health and Human Development. Pediatric Pathology 11:677-684.
  2. Beckwith J.B. 1970. Discussion of terminology and definition of the sudden infant death syndrome. In Bergman A.B; Beckwith J.B. & Ray C.G. (eds) Proceedings of the second international conference on the causes of sudden deaths in infants. Seattle: University of Washington Press. 14–22.
  3. Kinney H.C. & Thach B.T. 2009. The sudden infant death syndrome. New Engl. J. Med. 361 (8): 795–805. [1]
  4. 4.0 4.1 Vennemann M.M.; et al. (2007). "Sudden infant death syndrome: no increased risk after immunisation". Vaccine. 25 (2): 336–40. doi:10.1016/j.vaccine.2006.07.027. PMID 16945457.
  5. 5.0 5.1 Sudden Infant Death Syndrome (SIDS) and vaccines https://www.cdc.gov/vaccinesafety/Concerns/sids_faq.html
  6. Glatt, John (2000). Cradle of death: a shocking true story of a mother, multiple murder, and SIDS. Macmillan. ISBN 0-312-97302-0.
  7. Havill, Adrian (2002). While innocents slept: a story of revenge, murder, and SIDS. Macmillan. ISBN 0-312-97517-1.
  8. Krous H.F (2012). "A commentary on changing infant death rates and a plea to use sudden infant death syndrome as a cause of death". Forensic Sci Med Pathol. 9 (1): 91–93. doi:10.1007/s12024-012-9354-x. PMID 22715066. S2CID 1073084.
  9. 9.0 9.1 9.2 9.3 Sullivan FM, Barlow SM (2001). "Review of risk factors for Sudden Infant Death Syndrome". Paediatric Perinatal Epidemiology. 15 (2): 144–200. doi:10.1046/j.1365-3016.2001.00330.x. PMID 11383580.
  10. Office of the Surgeon General of the United States Report on Involuntary Exposure to Tobacco Smoke Archived 2011-08-06 at the Wayback Machine(PDF)
  11. Bajanowski T., Brinkmann B., Mitchell E., Vennemann M., Leukel H., Larsch K., Beike J., Gesid G. (2008). "Nicotine and cotinine in infants dying from sudden infant death syndrome". International Journal of Legal Medicine. 122 (1): 23–28. doi:10.1007/s00414-007-0155-9. PMID 17285322. S2CID 26325523.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. Lavezzi AM, Corna MF, Matturri L (July 2010). "Ependymal alterations in sudden intrauterine unexplained death and sudden infant death syndrome: possible primary consequence of prenatal exposure to cigarette smoking". Neural Dev. 19 (5): 17. doi:10.1186/1749-8104-5-17. PMC 2919533. PMID 20642831.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  13. 13.0 13.1 13.2 13.3 Moon RY, Fu L (July 2012). "Sudden infant death syndrome: an update". Pediatrics in Review / American Academy of Pediatrics. 33 (7): 314–20. doi:10.1542/pir.33-7-314. PMID 22753789.
  14. 14.0 14.1 Fleming PJ, Levine MR, Azaz Y, Wigfield R, Stewart AJ (June 1993). "Interactions between thermoregulation and the control of respiration in infants: possible relationship to sudden infant death". Acta Paediatr Suppl. 82 (Suppl 389): 57–9. doi:10.1111/j.1651-2227.1993.tb12878.x. PMID 8374195. S2CID 44497216.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  15. Moon RY, Horne RS, Hauck FR (November 2007). "Sudden infant death syndrome". Lancet. 370 (9598): 1578–87. doi:10.1016/S0140-6736(07)61662-6. PMID 17980736. S2CID 24624496.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. McIntosh CG, Tonkin SL, Gunn AJ (2009). "What is the mechanism of sudden infant deaths associated with co-sleeping?". N. Z. Med. J. 122 (1307): 69–75. PMID 20148046.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. Carpenter R, McGarvey C, Mitchell EA, Tappin DM, Vennemann MM, Smuk M, Carpenter JR (2013). "Bed sharing when parents do not smoke: is there a risk of SIDS? An individual level analysis of five major case-control studies". BMJ Open. 3 (5): e002299. doi:10.1136/bmjopen-2012-002299. PMC 3657670. PMID 23793691.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  18. Moon RY (November 2011). "SIDS and other sleep-related infant deaths: expansion of recommendations for a safe infant sleeping environment". Pediatrics. 128 (5): 1030–9. doi:10.1542/peds.2011-2284. PMID 22007004. S2CID 9668728.
  19. Hauck, FR; Thompson, JM; Tanabe, KO; Moon, RY; Vennemann, MM (July 2011). "Breastfeeding and reduced risk of sudden infant death syndrome: a meta-analysis". Pediatrics. 128 (1): 103–10. doi:10.1542/peds.2010-3000. PMID 21669892. S2CID 1257376.
  20. 20.0 20.1 CDC WONDER online database
  21. Hunt CE (November 2007). "Small for gestational age infants and sudden infant death syndrome: a confluence of complex conditions". Arch. Dis. Child. Fetal Neonatal Ed. 92 (6): F428–9. doi:10.1136/adc.2006.112243. PMC 2675383. PMID 17951549.
  22. Poets CF, Samuels MP, Wardrop CA, Picton-Jones E, Southall DP (April 1992). "Reduced haemoglobin levels in infants presenting with apparent life-threatening events—a retrospective investigation". Acta Paediatr. 81 (4): 319–21. doi:10.1111/j.1651-2227.1992.tb12234.x. PMID 1606392. S2CID 33298390.{{cite journal}}: CS1 maint: multiple names: authors list (link)
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  24. See CDC WONDER online database and http://www3.who.int/whosis/menu.cfm?path=whosis,inds,mort&language=english Archived 2004-06-27 at the Wayback Machine for data on SIDS by gender in the US and throughout the world.
  25. Mage DT & Donner M. (1997). "A genetic basis for the sudden infant death syndrome sex ratio". Med Hypotheses. 48 (2): 137–142. doi:10.1016/S0306-9877(97)90280-2. PMID 9076695.
  26. Mage DT, Donner EM (September 2004). "The fifty percent male excess of infant respiratory mortality". Acta Paediatr. 93 (9): 1210–5. doi:10.1080/08035250410031305. PMID 15384886. Archived from the original on 2020-04-08. Retrieved 2016-01-20.
  27. Behere, SP; Weindling, SN (2014). "Inherited arrhythmias: The cardiac channelopathies". Annals of Pediatric Cardiology. 8 (3): 210–20. doi:10.4103/0974-2069.164695. PMC 4608198. PMID 26556967.
  28. Pickett, KE, Luo, Y, Lauderdale, DS. Widening Social Inequalities in Risk for Sudden Infant Death Syndrome. Am J Public Health 2005;94(11):1976–1981. doi:10.2105/AJPH.2004.059063
  29. 29.0 29.1 Mitchell, E A; Stewart, A W; Clements, M (1 December 1995). "Immunisation and the sudden infant death syndrome. New Zealand Cot Death Study Group". Archives of Disease in Childhood. 73 (6): 498–501. doi:10.1136/adc.73.6.498. PMC 1511439. PMID 8546503.
  30. 30.0 30.1 Fleming, P. J (7 April 2001). "The UK accelerated immunisation programme and sudden unexpected death in infancy: case-control study". BMJ. 322 (7290): 822. doi:10.1136/bmj.322.7290.822. PMC 30557. PMID 11290634.
  31. 31.0 31.1 Vennemann, M.M.T.; Höffgen, M.; Bajanowski, T.; Hense, H.-W.; Mitchell, E.A. (2007). "Do immunisations reduce the risk for SIDS? A meta-analysis". Vaccine. 25 (26): 4875–9. doi:10.1016/j.vaccine.2007.02.077. PMID 17400342.
  32. 32.0 32.1 Hoffman, HJ; Hunter, JC; Damus, K; Pakter, J; Peterson, DR; van Belle, G; Hasselmeyer, EG (April 1987). "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". Pediatrics. 79 (4): 598–611. doi:10.1542/peds.79.4.598. PMID 3493477. S2CID 37163477. Retrieved 10 March 2015.
  33. 33.0 33.1 Carvajal, A; Caro-Patón, T; Martín de Diego, I; Martín Arias, LH; Alvarez Requejo, A; Lobato, A (4 May 1996). "[DTP vaccine and infant sudden death syndrome. Meta-analysis]". Medicina Clinica. 106 (17): 649–52. PMID 8691909.
  34. Weber MA, Klein NJ, Hartley JC, Lock PE, Malone M, Sebire NJ (May 31, 2008). "Infection and sudden unexpected death in infancy: a systematic retrospective case review". Lancet. 371 (9627): 1848–53. doi:10.1016/S0140-6736(08)60798-9. PMID 18514728. S2CID 8017934.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  35. Mitchell EA (November 2009). "SIDS: past, present and future". Acta Paediatrica (Oslo, Norway : 1992). 98 (11): 1712–9. doi:10.1111/j.1651-2227.2009.01503.x. PMID 19807704. S2CID 1566087.
  36. Mitchell EA, Hutchison L, Stewart AW (July 2007). "The continuing decline in SIDS mortality". Arch Dis Child. 92 (7): 625–6. doi:10.1136/adc.2007.116194. PMC 2083749. PMID 17405855.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  37. "What Can Be Done?". American SIDS Institute. Archived from the original on 2008-09-12. Retrieved 2016-01-20.
  38. "The Changing Concept of Sudden Infant Death Syndrome: Diagnostic Coding Shifts, Controversies Regarding the Sleeping Environment, and New Variables to Consider in Reducing Risk". American Academy of Pediatrics. Archived from the original on 2008-12-03. Retrieved 2008-11-06.
  39. L'Hoir MP, Engelberts AC, van Well GT, McClelland S, Westers P, Dandachli T, Mellenbergh GJ, Wolters WH, Huber J (1998). "Risk and preventive factors for cot death in The Netherlands, a low-incidence country". Eur. J. Pediatr. 157 (8): 681–8. doi:10.1007/s004310050911. PMID 9727856. S2CID 21642651.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  40. Müller-Nordhorn, Jacqueline; Hettler-Chen, Chih-Mei; Keil, Thomas; Muckelbauer, Rebecca (28 January 2015). "Association between sudden infant death syndrome and diphtheria-tetanus-pertussis immunisation: an ecological study". BMC Pediatrics. 15 (1): 1. doi:10.1186/s12887-015-0318-7. PMC 4326294. PMID 25626628.