Sleep Related Deaths

Every year in the United States, approximately 3,500 babies die suddenly and unexpectedly. Of these sudden unexpected infant deaths (SUID), approximately one half or 1,500 babies die from SIDS (Sudden Infant Death Syndrome). Despite infant safe sleep educational efforts dating back to 1992 with the national Back to Sleep Campaign and the current Safe to sleep Campaign, we are still losing thousands of babies suddenly and unexpectedly. In Ohio alone, nearly 3 infant deaths each week are sleep related!
We know that there are no ways to prevent all sudden unexpected infant deaths but there are protective measures parents and caregivers can take to reduce the risk of this happening to their baby. Many of the risk factors for SIDS and sleep related infant deaths are similar. Because of this, the American Academy of Pediatrics (AAP) expanded their recommendations in 2011 and focused on safe sleep environments that will reduce the risk of all sleep related infant deaths including SIDS.


SUID is a death of an infant less than 1 year of age that occurs suddenly and unexpectedly whether explained or unexplained.  The manner and cause of death is not immediately obvious prior to investigation.  There are several causes of death that fall under the category of SUID including SIDS, accidental suffocation, positional asphyxia and undetermined.   Even when a thorough post mortem autopsy is completed by a medical examiner it is often hard to differentiate between SIDS and other types of sudden unexpected infant death such as accidental suffocation in bed.  Unfortunately, according to recent statistics approximately 80 – 90% of sudden unexpected infant deaths are caused by unsafe sleep practices such as sleep position, bed sharing and soft bedding. Other causes of SUID include infection, genetic cardiac disorders, inherited metabolic disorders and trauma (accidental or non-accidental).  Sleep Related Infant Deaths are those deaths which happen suddenly and unexpectedly in a sleep environment.


SIDS is the sudden death of an infant under 1 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. (Willinger, et al., 1991). 

Most researchers now believe that babies are born with one or more conditions that make them especially vulnerable to stressors that occur in the normal life of an infant, including internal and external influences.   SIDS is referred to as a diagnosis of exclusion and can only be determined after ruling out all other causes.  It cannot be prevented and there is no way to determine which babies will die of SIDS.  SIDS is the leading cause of infant death for babies one month to one year of age and the third leading cause of infant mortality in the United States.

What are the Risk Factors for SIDS and SUID? 

  • Prone (lying on stomach) or side sleeping
  • Sleep position
  • Sleeping on a soft surface
  • Babies who share a sleep surface
  • Maternal smoking during and/or after pregnancy
  • Overheating
  • Late or no prenatal care
  • Young maternal age – babies born to mothers who are less than 20 years old at the time of their first pregnancy
  • Pre-term birth and/or low birth weight
  • Multiples
  • Male gender
  • African American and American Indian babies have 2-3 times greater risk of SIDS

Currently there is no known way to prevent all sudden infant deaths but there are protective measures parents and caregivers can take to reduce the risk.  Many of the risk factors for SIDS and other sleep related infant deaths are very similar which is why the American Academy of Pediatrics (AAP) expanded their recommendations in October 2011 to include ways to reduce the risk of all sleep related infant deaths including SIDS. The recommendations were further expanded in 2016.

Scientists also know that certain environmental and behavioral influences (called risk factors) can make an individual more susceptible to disease or ill health. Although risk factors are not necessarily the cause of a condition, by studying risk factors, scientists are able to better understand a disease or condition, which often leads to detecting a cause.

Researchers and clinicians continue to try to identify risk factors that can be modified or controlled to reduce an infant's risk for SIDS/SUID.

Infant Sleep Position 

In April 1992, the American Academy of Pediatrics (AAP) Task Force on Infant Sleep Position issued a statement recommending that infants be placed on their backs to sleep to reduce the risk of SIDS. Then, in 1994, the NIH led Back to Sleep Campaign began their national public service initiative to disseminate the AAP's recommendation that infants be placed on their back to sleep.

Between 1992 and 1998, among U.S. infants, stomach (prone) sleeping decreased more than 70 percent to approximately 20 percent. During that same time frame, the number of SIDS deaths declined by more than 40 percent (Willinger et al., 1998; AAP, 2000; NICHD, 2001). Not surprisingly, most researchers, policymakers, and SIDS professionals agree this significant decline occurred largely as a result of changing sleep position (AAP, 2000).
In September 2012, the NIH led Back to Sleep Campaign expanded their safe infant sleep outreach effort to reduce the rate of all sleep-related infant deaths.  This new campaign is now called the Safe to Sleep Campaign.  This campaign emphasizes other ways to provide a safe sleep environment for babies.  Babies should sleep in their own safe sleep environment and not on an adult bed, without any soft bedding such as blankets or quilts.  Safe to Sleep also emphasizes breast feeding infants when possible, and eliminating other risks to infant health such as overheating, exposure to tobacco smoke and a mother’s use of alcohol and illicit drugs.

Rates of SIDS are over twice as high among American Indians and African-Americans compared with Whites. Prone sleeping was found to be a significant risk factor for SIDS in an African-American urban sample (Hauck et al., 2002). These authors recommend educational outreach to the African-American community. 

Another recent study of the relationship between infant sleep position and SIDS concluded that infants placed in an unaccustomed prone or side sleeping position are at a higher risk of SIDS (Li et al., 2003). This ethnically diverse, population-based, case-controlled study was conducted in 11 counties in California. The health message from this research is that babies should be on their backs for all sleep, including naps.

Exposure to Smoke

Researchers have concluded that if a mother smokes during or after pregnancy, she is placing her infant at a greater risk for SIDS (AAP, 2000). Some studies suggest that exposure of the newborn to tobacco smoke (whether or not the mother smokes) may be associated with an increased risk for SIDS. In a 1997 policy statement, AAP cautioned, "Exposure of children to environmental tobacco smoke is associated with increased rates of lower respiratory illness and increased rates of middle ear effusion, asthma, and SIDS" (AAP, 1997). Australian studies have found that many infants and children exposed to environmental tobacco smoke have levels of cotinine that are similar to those in active smokers. (Daly et al, 2001)


According to AAP (2000), some evidence points to an association of the amount of clothing or blankets on an infant, room temperature, and the time of the year with an increased risk for SIDS. The increased risk associated with overheating is particularly clear when infants are placed on their stomachs (prone).

AAP cautions that the possible relationship between clothing and climate as stand-alone factors (or as a cluster of environmental risk factors) is less clear. Moreover, although the number of recorded SIDS deaths has been higher in the winter months, that increase may be due to the greater frequency of colds, flu, and other infections during the winter.

Infant Bedding

The AAP recommendations of October 2011 advises to  keep all soft bedding out of the baby’s crib including loose bedding, stuffed animals and bumper pads.  Soft bedding can increase the risk of a SIDS death by 5 times (Hauck, 2003) and many sleep–related infant deaths due to suffocation involve pillows, quilts and extra bedding (CPSC).
In recent safety alerts, CPSC has warned parents to guard against unfounded claims from manufacturers of some infant bedding materials that the use of certain products can reduce SIDS. Parents and other caregivers need to be aware that there is no product currently available that can guarantee prevention of a SIDS death.