Fact Sheet

Sudden Unexpected Infant Deaths (SUID) are deaths that occur suddenly and unexpectedly in previously healthy infants and have no obvious cause of death prior to investigation (unexplained). SUID excludes deaths with an obvious cause, e.g., motor vehicle accidents. Sudden Infant Death Syndrome (SIDS) is one subgroup of SUID. Others are accidental suffocation, infections or other known medical causes, and homicide. SIDS is defined as “…sudden death of an infant under one year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history.” There is inconsistency in coding SUID/SIDS deaths on death certificates. Some medical examiners are calling fewer deaths SIDS, instead coding them as “accidental suffocation” or “unknown.” Regardless of how they are coded, many Child Death Review teams review SUID/SIDS deaths because they believe they are preventable.

According to the National Center on Health Statistics (NCHS), 1,679 infants died of SIDS in the United States in 2012, the third leading cause of death of infants less than one year of age after congenital anomalies and pre-term birth. Another 965 died of suffocation. In 2000, 2,523 died from SIDS and another 526 from suffocation. This shift in numbers may reflect a shift in coding by medical examiners.

Despite a major drop in SIDS since the Back to Sleep movement began in the early 90’s, SIDS/SUID remains the leading cause of death for infants between one month and one year of age. American Indian/Alast Native infants have the highest rate of SIDS/SUID deaths, more than three times that of white infants. Non-Hispanic black infants also die of SUID/SIDS/asphyxia at a rate disproportionately higher than rates for white babies.

The majority of these suffocations happen to infants in unsafe sleeping environments. They suffocate when another person lays over them or when they smother in bedding or furniture. Infants who suffocate often have no clinical findings at autopsy. It is only through a comprehensive scene investigation that unintentional suffocation can be distinguished from SIDS or intentional suffocations (homicides). Yet, even with complete investigations, a large number of suffocation deaths are still reported as “manner undetermined,” further highlighting the difficulty investigators have in determining how the infants died. Given these risks, the AAP recommends that babies sleep alone in cribs without bedding and that they room-share instead of bed-share.

Some proponents of bed- sharing argue that bed-sharing promotes breastfeeding. However, research has shown that many of the benefits received from bed-sharing can be derived from the practice of having the infant sleep separately but in the same room as the parent.

Major Risk Factors

  • Infants sleeping on their stomachs
  • Soft infant sleep surfaces and loose bedding, toys or other objects in sleep environment
  • Maternal smoking during pregnancy
  • Second-hand smoke exposure
  • Overheating
  • Prematurity and/or low birth weight
  • Sharing a bed with others.
  • Sleeping place other than crib (e.g., adult bed, couch, chair)
  • Faulty design of cribs or beds.
  • Obesity, fatigue, or drug or alcohol use by persons supervising or sleeping with child.
  • Quality of supervision at time of death.
  • Family’s ability to provide safe sleep or play environment for child.

Records Needed for Case Review

  • Autopsy reports
  • Scene investigation reports and photos
  • Doll reenactment photos and reports
  • Prenatal, birth and health records
  • Interviews with family members
  • Day Care Licensing investigative reports
  • EMS run reports
  • Emergency Department reports
  • Prior CPS history on child, caregivers and/or person supervising child at time of death
  • Criminal background checks on person supervising the child at time of death
  • Reports of home visits from public health or other services
  • Any information on prior deaths of children in family


  • Education in childbirth classes and hospitals of expectant and new parents on safe infant sleep environments
  • In-hospital assessments by nurses with parents to assess a baby’s sleep environment when it goes home
  • Crib distribution programs for families
  • Parent education campaigns on room-sharing not bed-sharing
  • Smoking cessation education and support for pregnant and parenting women and other caregivers
  • Working with hospitals and providers to make sure that every infant that leaves the hospital has a primary care provider established
  • Encouraging breastfeeding
  • Pacifiers offered at each sleep
  • Avoid products that claim to reduce the risk of SIDS
  • Parents educated not to let baby get too hot
  • The “Back to Sleep” campaign: baby sleeps on her back every time
  • Specific messages targeted to families and childcare providers who traditionally practice stomach sleep positions and/or bed-sharing
  • Education of health care providers on giving guidance on safe sleep and bed sharing to parents and caregivers
  • Licensing requirements for daycare providers on safe sleep environments and infant sleep positions