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CME: Pediatrics

Preventing sudden infant death syndrome and other sleep-related infant deaths

Maged, Mazal MS, PA-C; Rizzolo, Denise PhD, MS, PA-C

Author Information
Journal of the American Academy of Physician Assistants: November 2018 - Volume 31 - Issue 11 - p 25-30
doi: 10.1097/01.JAA.0000546475.33947.44
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Box 1
Box 1

According to the CDC, about 3,600 infants died in the United States from sudden unexpected infant death (SUID) in 2016.1 Sudden infant death syndrome (SIDS), the most common type of SUID, remains the leading cause of postneonatal death in the United States.1 Despite the continued measures for education and risk reduction, the SUID rate has remained relatively unchanged over the past 10 years. For unknown reasons, the incidence increased in 2015, and slightly decreased in 2016.1,2 Standardized guidelines have been developed for conducting thorough case investigations to improve classification of sleep-related infant deaths.1 Distinguishing SIDS from other sleep-related infant deaths is challenging because these deaths often are unwitnessed and no test can differentiate SIDS from suffocation.1 As SIDS is a diagnosis of exclusion, all other causes of death must initially be ruled out, including unintentional or intentional injury, cardiovascular anomalies, and metabolic or genetic disorders.3 Although the cause of SIDS remains unknown, modifying risk factors and taking protective measures can significantly reduce the likelihood of SIDS.1,2

The American Academy of Pediatrics (AAP) recently updated its guidelines for safe sleep environments for infants (Table 1).4 Clinicians play an important role in supporting the AAP's efforts to reduce the incidence of sleep-related SUID by educating parents and caregivers on necessary precautions for preventing SUID.4 Types of SUID are described in Table 2.

AAP recommendations for a safe infant sleep environment4
Common terms and definitions1,2
Box 2
Box 2


SIDS is more prevalent in boys than girls, with a peak in incidence between 2 and 4 months of age; 90% of deaths occur before the infant is age 6 months.5 Eighty percent of sleep-related infant deaths occur at the child's home.6 Most out-of-home deaths occur at a relative's home, followed by child-care settings such as a day care or a babysitter's home.6 A study by Kassa and colleagues found that infants who died out-of-home were more likely to be placed in the prone position to sleep and/or in a stroller or car seat.6

Infant mortality in the United States remains higher than in most European countries.7 Since the 1994 launch of the “Back to Sleep” campaign (now called “Safe to Sleep”) led by the National Institute of Child Health and Human Development (NICHD), infant mortality from SIDS has decreased by more than 50% but began to plateau in 2001.2 Simultaneously, other sleep-related causes of SUID such as asphyxiation, strangulation, and entrapment have increased in incidence.2

SUID mortality has marked ethnic and racial disparities.8 Rates are highest among American Indian/Alaska Native infants followed by non-Hispanic black infants.8 In 2013, the SUID rate was double for these two groups compared with non-Hispanic white infants.8 The variations in racial and ethnic SUID rates likely are correlated with cultural differences in infant sleep position, use of potentially hazardous bedding, and infant bedsharing.9-11 The National Infant Sleep Position Study showed a continual increase in bedsharing from 1993 (6.5%) to 2010 (13.5%) among black and Hispanic infants.11


The Triple-Risk Model, described in 1994 by Filiano and Kinney, states that SIDS occurs in infants with underlying vulnerability (brainstem abnormality or genetic pattern) who experience a trigger event or external stressor (airway obstruction, prone sleeping) during a critical development period.12 The model predicts that SIDS occurs when these three factors overlap.4,12 The AAP proposes that by removing one of the factors, SIDS will be less likely to occur.2,4 Of these factors, the one believed to be the most influential is exogenous or external stressors.4


The risk factors for SIDS are similar to risk factors for other sleep-related infant deaths.2 More than 95% of SUIDs are associated with one or more risk factors.13 The AAP recommends reducing the risk of SUID by focusing on creating a safe sleep environment and addressing modifiable risk factors:4

  • Maternal smoking. The risk of SIDS is five times higher when mothers smoke during pregnancy.14,15
  • Young maternal age (under age 20 years).1,2,4,13,14
  • An infant's exposure to smoke after birth has also been identified as a separate risk factor.16
  • Preterm birth, defined as an infant born at less than 37 weeks.17 Infants born at low or very low birth weights are three to four times more likely to succumb to SIDS.17 A study by Ostfeld and colleagues examined data from the United States, linking infant birth and death certificate period files from 2012 to 2013 to correlate SUID with gestational age.17 The data demonstrated an inverse relationship between gestational age and SUID. As gestational age increases and infants are born closer to term, the risk of SUID declined.17 Mothers who smoke during pregnancy are at a markedly increased risk in delivering preterm. Thus, clinicians should educate mothers on the importance of smoking cessation during pregnancy.15

Environmental risk factors associated with SUID are prone sleeping; sleeping on soft surfaces; sleeping with blankets, pillows, and/or other soft objects; bedsharing; and overheating.1,2,4,9-11,13 The prone sleep position is the strongest modifiable risk factor for SIDS.18 The New Zealand Cot Study, a 3-year multicenter case control study, sought to identify risk factors for SIDS.18 In 1987, the first year of the study, Mitchell and colleagues reviewed 128 cases of SIDS with 503 controls, and found 74% of the SIDS infants, compared with 44% of the controls, were sleeping in the prone position.18 Infants placed in the prone position had nearly triple the risk for SIDS, according to the study results.18


Supine sleep position

All infants should be placed for sleep solely in the supine position up to age 1 year.4 Previously presumed as safe, the side sleep position has been shown to be as risky as prone sleeping for SUID.19 Infants placed on their sides are at increased risk of being found in the prone position.20

Infants accustomed to sleeping on their backs have a seven to eight times increased risk of SIDS when placed on their stomachs compared with infants who usually are placed on their stomachs to sleep.21 The AAP recommends that all infants be placed in the supine position to sleep, for every sleep and by every caregiver.4

From 1994 until positioning became a risk factor for SIDS, neonatal intensive care units (NICUs) placed premature infants in the prone position to sleep because that position was believed to improve respiratory mechanics.17 The AAP now recommends that premature infants be placed in the supine position for sleep as soon as they are deemed medically stable, allowing them sufficient time to acclimate to sleeping in the supine position.4,17 This, in turn, facilitates a smoother transition when the infant is discharged.4 Parents who observe proper infant sleep positioning in the NICU should be more likely to adhere to the recommended sleep position when their infant is home.4

According to the North American Society for Pediatric Gastroenterology and Nutrition, infants diagnosed with gastroesophageal reflux (GERD) should be placed in the supine position to sleep because the risk of SIDS outweighs the benefits of prone positioning to improve GERD symptoms.22 An exception is made for infants at an increased risk of death from GERD compared with SIDS.22 For example, infants with anatomic abnormalities such as type 3 or 4 laryngeal clefts who have not undergone antireflux surgery and have impaired airway protective mechanisms should be placed prone to sleep.22

Firm sleep surface

Infants should sleep on a firm mattress covered with a fitted sheet.4 Blankets, pillows, soft toys, or any other bedding should not be used in the crib while the infant is sleeping, as these items increase the risk for SIDS, accidental suffocation and strangulation in bed, or entrapment.4 Infant sleep surfaces (crib, bassinet, portable crib, or play yard) should meet the safety standards of the federal Consumer Product Safety Commission (CPSC).4 Although not specifically listed in the AAP recommendations as an example of soft bedding or safe sleep surface, air mattresses are not recommended for infant sleep because they increase the risk of suffocation.23 Despite a CSPC warning, air mattresses are becoming increasingly popular among those living in lower socioeconomic status as they are less expensive and can be used by multiple infants and children.23,24

Infants should not sleep in car seats, infant swings, or strollers.4,25 Infants younger than age 4 months have poor head control, and when placed in sitting positions to sleep can experience flexion of the head that may increase the risk of upper airway obstruction and oxygen desaturation. Parents should reposition an infant's head when necessary, and move infants who fall asleep in one of these types of carriers to an appropriate sleep surface as soon as possible.4,25

An infant's crib or other CPSC-approved sleep surface should be placed in a hazard-free location, defined as an area free of devices that pose a risk of strangulation such as dangling cords and electric wires, for example.4

Rooming with parents

Room-sharing has been shown to decrease SIDS risk by 50%.19 AAP recommends that infants share a room with parents at least for the first 6 months, and optimally for 1 year after birth.4 This is a significant change from the previous recommendation that warned against room-sharing because of negative consequences such as poor sleep quality for infants and difficult bedtime routines.4,26 Room-sharing can facilitate feeding, comforting, and monitoring of the infant.4

Although room-sharing is recommended, infants and parents or caregivers should sleep on separate surfaces.4 Bedsharing increases the risk of SUID.4,11 The risk substantially increases when infants share a bed with a parent who smokes or has consumed alcohol, when infants are younger than age 4 months or are preterm or low birth weight, when infants share a small or soft-surface bed or when soft bedding or accessories are used, when multiple people share the bed, or when infants share the bed with someone other than their parents.4

Couches and armchairs are unsafe places for an infant to sleep, and pose an increased risk for SIDS, entrapment, and suffocation.4,27 When feeding an infant at night, the caregiver should be on an adult bed rather than a couch or recliner.27 When feeding an infant in bed, the caregiver should remove all pillows, blankets, and soft items in the immediate area to prevent accidental suffocation.4 When a caregiver feels sleepy, the infant should be placed supine in the bassinet.4

Avoiding overheating

Avoid blankets, head coverings, and excess clothing on infants when putting them to sleep because they can lead to an infant overheating—an additional risk factor for sleep-related SUID.28 Research also suggests that sleeping in the prone position puts an infant at risk for overheating.28

Encouraging breastfeeding

One of the strongest protective measures against SIDS is breastfeeding, which provides infants with immunoglobulins and cytokines needed to safeguard them from developing infections.4,29 Immunoglobulins and cytokines help shield infants during the vulnerable period when SIDS commonly occurs.29 Any amount of breastfeeding is more protective than none.4,29 Exclusively breastfeeding for the first month reduces an infant's risk of SIDS by 50%.30

When discussing breastfeeding with new parents, clinicians should also discuss pacifier use, which is considered a protective factor against SUID.4,31 Although the exact mechanism for its protective effect is unclear, pacifier use may maintain airway patency during sleep by favorably modifying autonomic control of breathing and cardiovascular stability.31 Some parents are reluctant to introduce pacifiers for fear of reducing the duration of breastfeeding.31 However, a systematic review found no adverse relationship between pacifier use and breastfeeding.32,33 In 2012, the AAP revised its breastfeeding and pacifier use recommendations, adding that introducing pacifiers to infants should be done after breastfeeding has been well established.32,33

Optimizing pre- and postnatal care

Pregnant women should obtain prenatal care early in their pregnancy.4 Women should avoid tobacco use and alcohol consumption during pregnancy, immediately after giving birth, and/or until cessation of breastfeeding.4,14,16,17 Smoke exposure in utero puts fetuses at an increased risk for preterm birth and low birth weight.3,4,16,17 If all maternal smoking was eliminated, an estimated one-third of SUIDs could be prevented.4,15


Researchers must understand the barriers to parental adherence if they are to develop efficient evidence-based strategies to reduce SIDS and other sleep-related infant deaths. In a study by Schnitzer and colleagues, data were obtained from the National Child Death Review Case Reporting System for 3,136 sleep-related infant deaths from nine states from 2005 to 2008.33 The results showed that only 25% of infants were sleeping in a crib or on their backs at the time of death; 70% were on surfaces not intended for infant sleep (parent bed); and 64% were sharing a bed.33 The study identified modifiable sleep environment risk factors in a large portion of SUIDs that were assessed.33 Schnitzer and colleagues support the recommendations for safe infant sleep practices—infants should be placed on a firm crib mattress in the supine position without soft bedding and with no objects in the crib.33

The disparity in the incidence of SUID among races and ethnicities is explained by different cultural beliefs and practices in infant sleep location and position.4,9 A survey by Colson and colleagues assessed 3,297 mothers recruited from 32 US hospitals to determine intent and actual practice of sleep position in addition to explanations associated with their choices.4,9 The study found that 77.3% of mothers reported that they usually placed their infants in the supine position for sleep but only 43.7% of mothers said they both intended to and exclusively did so.9 Survey results showed that black mothers and those who did not complete high school were more likely to intend to use the prone position.9 Elements involving a mother's failure to adhere are associated with behavior factors such as attitudes, subjective norms, perceived control (mothers believe infant sleep position is not their decision), along with physician advice.9 When educating parents about risk-reduction strategies, consider these trends and develop culturally suitable approaches to fit each community.8,12

Using hazardous bedding is a modifiable risk factor for SIDS and unintentional sleep-related suffocation.10 Data from the National Infant Sleep Position Study analyzed by Shapiro-Mendoza and colleagues revealed that about one-half of US infants are placed to sleep with potentially hazardous bedding.4,10,34 The strongest predictors for infant bedding use were young maternal age, lack of a college education, and nonwhite race or ethnicity.34 Parents who elected to use hazardous bedding were primarily concerned about their infants' comfort.34 Parents and caregivers must continue to be educated on these hazards.1

Similar to other environmental risk factors, bedsharing is common among particular cultures and ethnicities.13 Bedsharing is more prevalent in low-income households that cannot afford a crib or separate sleep surface for each family member.4,8,23

A randomized clinical trial by Moon and colleagues assessed the effectiveness of a mobile health intervention on improving adherence to safe sleep guidelines.26 Parents received emails and texts containing health messages and education videos for 2 months after their infant's birth.26 The mobile health intervention was effective in improving safe infant sleep practices, particularly room-sharing without bedsharing and avoiding use of soft bedding.26 This clinical trial demonstrated a statistically significant increase in parental adherence to safe sleep practices. The parents who received the mobile health intervention had a 10% higher adherence compared with control groups, who received alternative interventions or no intervention.26

Despite proven risk-reduction strategies to lower the likelihood of sleep-related SUID, entirely preventing SUID is likely impossible.


Interventions to effectively promote safe infant sleep practices and reduce sleep-related SUID are crucial to addressing this public health issue.35 Education efforts should specifically target high-risk populations that do not adhere to safe sleep recommendations. In addition to the current nationwide campaigns and continued efforts from the federal Department of Health and Human Services, clinicians should use all appropriate opportunities to educate caregivers about the importance of early prenatal care, avoiding tobacco use during pregnancy and after delivery, encouraging breastfeeding, and promoting a safe infant sleep environment.4 To successfully facilitate a change in parents' and caregivers' behaviors, clinicians must be cognizant of cultural beliefs and concerns that prevent adherence. The risks for sleep-related SUID are multifactorial; therefore, education on prevention must be comprehensive. Continued research, standardized hospital practice, and parent education may help reduce the incidence of sleep-related SUID in the United States.


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22. Rosen R, Vandenplas Y, Singendonk M, et al. Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition. J Pediatr Gastroenterol Nutr. 2018;66(3):516–554.
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sudden unexplained infant death; sudden infant death syndrome; SIDS; SUID; safe sleep; supine

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