II. Epidemiology
- Incidence: 0.57 per 1000 live births
- Responsible for 1400 to 2200 deaths per year in the United States
- Accounts for slighly less than half the number of unexpected infant deaths in the U.S.
- Ages affected: 1 to 6 months (peaks at ages 1-4 months)
- Males are more likely to die of SIDS (RR 1.2)
- SIDS occurs most often between midnight and 8 am
III. Pathophysiology
- Triple-Risk Model (SIDS is final common pathway of 3 contributing factors)
- Underlying Vulnerability (e.g. Prolonged QT, Autonomic Dysfunction)
- Exogenous Stress (e.g. prone position, smoke exposure)
- Stress occurs during critical time in development (age <1 year old)
IV. Risk Factors: Ordered by Level of Risk
- Major Risk Factors
- Bed Sharing with smoking mother (OR 13.90)
- Gestational age <37 weeks (OR 11.67)
- Bed Sharing with infant <12 weeks old (OR 10.37)
- Soft bedding material (OR 5.10)
- Prone sleeping position (OR 4.30)
- Low brth weight <2500 g (OR 3.3)
- Bed Sharing with non-smoking mother (OR 2.09)
- Mother smoked during pregnancy (OR 2.06)
- Other Risk Factors
- Protective Factors
- Up-to-date Immunizations
- Pacifier use during sleep (not attached)
- Breast Feeding
- References
V. Risk Factors: Ordered by Category
- Infant Factors (Non-Modifiable)
- Preterm Birth (Gestational age <37 weeks)
- Low birth weight <2500 g
- Family History of previous SIDS deaths
-
Sleep Environment
- Bed Sharing (Co-Sleeping) prior to 4 months of age (especially with smoking mother)
- Prone sleeping position (also side sleeping to lesser extent)
- Soft sleep surface (pillows, bedding)
- Substance Use by Parents
- Parental Smoking (associated with 61% of SIDS deaths)
- Maternal Alcohol Abuse (associated with 16% of SIDS deaths)
- Maternal Drug Abuse
- Socioeconomic Factors
- Teenage parents
- Minimal Prenatal Care
VI. History: By coroner or medical provider
- Reporting demographics
- Time infant was last normal
- Name of person who found the infant
- Infant status when found
- Respiratory status of infant when found (i.e. breathing or apneic)
- Sleep environment and surface on which the infant was found
- Items present around the infant when found (e.g. blankets)
- Position of infant when found (e.g. prone)
- Contributing factors
- Co-Sleeping
- Recent illness
VII. Diagnosis: Autopsy
- Assess for other possible cause
- Requires a full medical examiner evaluation into unexpected infant death
- SIDS is a diagnosis of exclusion after other causes have been evaluated
- Findings consistent with SIDS
VIII. Differential Diagnosis
- Apparent Life-Threatening Events In Children (ALTE or BRUE) or
- Anoxia (Aspiration, Asphyxiation, Drowning)
- Cardiac Arrhythmia or Congenital Heart Defect
- Dehydration
- Inborn Errors of Metabolism
- Overwhelming infection (e.g. Neonatal Sepsis, Pneumonia)
- Poisoning
- Trauma (including Non-accidental Trauma)
- Hyperthermia
IX. Management: Emergency Department
- Avoid cleaning baby post-Resuscitation
- Evaluate neck flexibility on intubation (stiff or flexible)
- Stiffness may suggest longer duration since time of death
- Rigor mortis cannot otherwise be determined in infants due to lack of musculature
- Describe secretions found in the airway
- Do not clear the suction canister of secretions until examined by coroner
-
Toxicology Screening
- May be performed during Resuscitation
- Coroner will perform if not already done
- Imaging
- Skeletal Survey is typically performed by coroner (multiple views, without limitations of radiation exposure)
X. Management: Family Support
- Counseling services
XI. Resources
- American SIDS Institute
XII. Prevention
- Avoid Bed Sharing (especially prior to 4 months of age)
- Bed Sharing is most dangerous on soft surface, substance use (e.g. Alcohol, Tobacco), age <12 weeks
- Room sharing for first 6 months, however, is recommended (may reduce SIDS risk 50%)
- Infants should sleep in their own bassinet or crib
- See Crib Safety
- Firm sleep surface
- No pillows, comforters, toys or bedding
- Layers of clothing (or wearable blankets) may be used instead
- Avoid hats after the first day of life (may increase risk of SIDS)
- Swaddling (snugly wrapped blanket) is considered safe until infant shows signs of rolling over (3-4 months)
- Swaddling can result in suffocation if infant rolls
- Avoid sleeping in a Car Seat or stroller (or other inclined device)
- Child should sleep in supine position (Back to sleep campaign)
- Practice prevention of Deformational Plagiocephaly (related to supine sleeping)
- Supervised prone position while infant is awake starting at 2 weeks of age
- Gradually advance supervised prone position to 15-30 minutes/day (at age 2 months)
- Limit time that infants are in Car Seats or strollers
- Gross Motor Delays may occur due to supine positioning, but resolve by 18 months old
- Back to sleep campaign started in 1992 and reduced SIDS Incidence by 39%
- Practice prevention of Deformational Plagiocephaly (related to supine sleeping)
- Pacifier Use
- Tobacco Cessation for parents (prior to pregnancy or prenatally is best)
- Keep Immunizations up-to-date
- Infant monitors are not recommended by AAP (not effective in preventing SIDS)
- Many OTC commercial cardiorespiratory monitors are directly marketed to parents
- Home monitors are expensive, inaccurate and offer false reassurance
- Breast Feeding substantially reduces SIDS Risk (OR 0.27)
XIII. References
- Bertone and Spangler in Herbert (2013) EM:Rap 13(11): 8-9
- Merenstein (1994) Handbook Pediatrics, Lange
- (1996) BMJ 313:191 [PubMed]
- (1996) BMJ 313:195 [PubMed]
- Adams (2015) Am Fam Physician 91(11): 778-83 [PubMed]
- Adams (2009) Am Fam Physician 79(10): 870-4 [PubMed]
- Alexander (2005) J Forensic Sci 50(1): 147-51 [PubMed]
- Darrow (2025) Am Fam Physician 111(2): 164-70 [PubMed]