According to the Centers for Disease Control & Prevention (CDC). each year in the United States, there are about 3,500 Sudden Unexpected Infant Deaths (SUID). These deaths occur among infants less than 1 year old and have no immediately obvious cause.

The three commonly reported types of SUID are:

• SIDS - About 1,500 infants died of SIDS in 2014.

• Unknown cause.

• Accidental suffocation and strangulation in bed.

What is SIDS? 

The Centers for Disease Control & Prevention (CDC) defines Sudden Infant Death Syndrome (SIDS) as the sudden death of an infant less than 1 year of age that cannot be explained after a thorough investigation is conducted, including a complete autopsy, examination of the death scene, and a review of the clinical history. About 1,500 infants died of SIDS in 2014. SIDS is the leading cause of death in infants 1 to 12 months old.

What causes SIDS?

The sudden death of an infant less than 1 year of age that can happen because of

• Suffocation by soft bedding—for example, when a pillow or waterbed covers an infant's nose and mouth.
• Overlay - when another person rolls on top of or against the infant while sleeping.
• Wedging or entrapment - when an infant is wedged between two objects such as a mattress and wall, bed frame, or furniture.
• Strangulation - for example, when an infant’s head and neck become caught between crib railings.

Recommendations To Reduce the Risk of SIDS and Other Sleep-Related Infant Deaths

1. Back to sleep for every sleep.

To reduce the risk of SIDS, infants should be placed for sleep in a supine position (wholly on the back) for every sleep by every caregiver until the child reaches 1 year of age. Side sleeping is not safe and is not advised.

1. The supine sleep position does not increase the risk of choking and aspiration in infants, even those with gastroesophageal reflux, because infants have airway anatomy and mechanisms that protect against aspiration. The American Academy of Pediatrics (AAP) concurs with the North American Society for Pediatric Gastroenterology and Nutrition that “the risk of SIDS outweighs the benefit of prone or lateral sleep position on GER [gastroesophageal reflux]; therefore, in most infants from birth to 12 months of age, supine positioning during sleep is recommended. …Therefore, prone positioning is acceptable if the infant is observed and awake, particularly in the postprandial period, but prone positioning during sleep can only be considered in infants with certain upper airway disorders in which the risk of death from GERD [gastroesophageal reflux disease] may outweigh the risk of SIDS.” Examples of such upper airway disorders are those in which airway-protective mechanisms are impaired, including infants with anatomic abnormalities, such as type 3 or 4 laryngeal clefts, who have not undergone antireflux surgery. There is no evidence to suggest that infants receiving nasogastric or orogastric feeds are at an increased risk of aspiration if placed in the supine position. Elevating the head of the infant’s crib is ineffective in reducing gastroesophageal reflux and is not recommended; in addition, elevating the head of the crib may result in the infant sliding to the foot of the crib into a position that may compromise respiration.

2. Preterm infants should be placed supine as soon as possible. Preterm infants are at increased risk of SIDS, and the association between prone sleep position and SIDS among low birth weight and preterm infants is equal to, or perhaps even stronger than, the association among those born at term. The task force concurs with the AAP Committee on Fetus and Newborn that “preterm infants should be placed supine for sleeping, just as term infants should, and the parents of preterm infants should be counseled about the importance of supine sleeping in preventing SIDS. Hospitalized preterm infants should be kept predominantly in the supine position, at least from the postmenstrual age of 32 weeks onward, so that they become acclimated to supine sleeping before discharge.” NICU personnel should endorse safe sleeping guidelines with parents of infants from the time of admission to the NICU.

3. As stated in the AAP clinical report, “skin-to-skin care is recommended for all mothers and newborns, regardless of feeding or delivery method, immediately following birth (as soon as the mother is medically stable, awake, and able to respond to her newborn), and to continue for at least an hour.” Thereafter, or when the mother needs to sleep or take care of other needs, infants should be placed supine in a bassinet. There is no evidence that placing infants on their side during the first few hours after delivery promotes clearance of amniotic fluid and decreases the risk of aspiration. Infants in the newborn nursery and infants who are rooming in with their parents should be placed in the supine position as soon as they are ready to be placed in the bassinet.

4. Although data to make specific recommendations as to when it is safe for infants to sleep in the prone or side position are lacking, studies establishing prone and side sleeping as risk factors for SIDS include infants up to 1 year of age. Therefore, the best evidence suggests that infants should continue to be placed supine until 1 year of age. Once an infant can roll from supine to prone and from prone to supine, the infant can be allowed to remain in the sleep position that he or she assumes. Because rolling into soft bedding is an important risk factor for SUID after 3 months of age, parents and caregivers should continue to keep the infant’s sleep environment clear of soft or loose bedding.

2. Use a firm sleep surface.

Infants should be placed on a firm sleep surface (eg, mattress in a safety-approved crib) covered by a fitted sheet with no other bedding or soft objects to reduce the risk of SIDS and suffocation.

1. A firm surface maintains its shape and will not indent or conform to the shape of the infant’s head when the infant is placed on the surface. Soft mattresses, including those made from memory foam, could create a pocket (or indentation) and increase the chance of rebreathing or suffocation if the infant is placed in or rolls over to the prone position.

2. A crib, bassinet, portable crib, or play yard that conforms to the safety standards of the Consumer Product Safety Commission (CPSC), including those for slat spacing less than 2-3/8 inches, snugly fitting and firm mattresses, and no drop sides, is recommended. In addition, parents and providers should check to make sure that the product has not been recalled. This is particularly important for used cribs. Cribs with missing hardware should not be used, nor should the parent or provider attempt to fix broken components of a crib, because many deaths are associated with cribs that are broken or with missing parts (including those that have presumably been fixed). Local organizations throughout the United States can help to provide low-cost or free cribs or play yards for families with financial constraints.

3. Bedside sleepers are attached to the side of the parental bed. The CPSC has published safety standards for these products, and they may be considered by some parents as an option. However, there are no CPSC safety standards for in-bed sleepers. The task force cannot make a recommendation for or against the use of either bedside sleepers or in-bed sleepers, because there have been no studies examining the association between these products and SIDS or unintentional injury and death, including suffocation.

4. Only mattresses designed for the specific product should be used. Mattresses should be firm and should maintain their shape even when the fitted sheet designated for that model is used, such that there are no gaps between the mattress and the wall of the crib, bassinet, portable crib, or play yard. Pillows or cushions should not be used as substitutes for mattresses or in addition to a mattress. Mattress toppers, designed to make the sleep surface softer, should not be used for infants younger than 1 year.

5. There is no evidence that special crib mattresses and sleep surfaces that claim to reduce the chance of rebreathing carbon dioxide when the infant is in the prone position reduce the risk of SIDS. However, there is no disadvantage to the use of these mattresses if they meet the safety standards as described previously.

6. Soft materials or objects, such as pillows, quilts, comforters, or sheepskins, even if covered by a sheet, should not be placed under a sleeping infant. If a mattress cover to protect against wetness is used, it should be tightly fitting and thin.

7. Infants should not be placed for sleep on beds, because of the risk of entrapment and suffocation. In addition, portable bed rails should not be used with infants, because of the risk of entrapment and strangulation.

8. The infant should sleep in an area free of hazards, such as dangling cords, electric wires, and window-covering cords, because these may present a strangulation risk.

9. Sitting devices, such as car seats, strollers, swings, infant carriers, and infant slings, are not recommended for routine sleep in the hospital or at home, particularly for young infants. Infants who are younger than 4 months are particularly at risk, because they may assume positions that can create a risk of suffocation or airway obstruction or may not be able to move out of a potentially asphyxiating situation. When infant slings and cloth carriers are used for carrying, it is important to ensure that the infant’s head is up and above the fabric, the face is visible, and the nose and mouth are clear of obstructions. After nursing, the infant should be repositioned in the sling so that the head is up, is clear of fabric, and is not against the adult’s body or the sling. If an infant falls asleep in a sitting device, he or she should be removed from the product and moved to a crib or other appropriate flat surface as soon as is safe and practical. Car seats and similar products are not stable on a crib mattress or other elevated surfaces. Infants should not be left unattended in car seats and similar products, nor should they be placed or left in car seats and similar products with the straps unbuckled or partially buckled.

3. Breastfeeding is recommended.

1. Breastfeeding is associated with a reduced risk of SIDS. Unless contraindicated, mothers should breastfeed exclusively or feed with expressed milk (ie, not offer any formula or other nonhuman milk-based supplements) for 6 months, in alignment with recommendations of the AAP.

2. The protective effect of breastfeeding increases with exclusivity. However, any breastfeeding has been shown to be more protective against SIDS than no breastfeeding.

4. It is recommended that infants sleep in the parents’ room, close to the parents’ bed, but on a separate surface designed for infants, ideally for the first year of life, but at least for the first 6 months.

There is evidence that sleeping in the parents’ room but on a separate surface decreases the risk of SIDS by as much as 50%. In addition, this arrangement is most likely to prevent suffocation, strangulation, and entrapment that may occur when the infant is sleeping in the adult bed.

1. The infant’s crib, portable crib, play yard, or bassinet should be placed in the parents’ bedroom until the child’s first birthday. Although there is no specific evidence for moving an infant to his or her own room before 1 year of age, the first 6 months are particularly critical, because the rates of SIDS and other sleep-related deaths, particularly those occurring in bed-sharing situations, are highest in the first 6 months. Placing the crib close to the parents’ bed so that the infant is within view and reach can facilitate feeding, comforting, and monitoring of the infant. Room-sharing reduces SIDS risk and removes the possibility of suffocation, strangulation, and entrapment that may occur when the infant is sleeping in the adult bed.

2. There is insufficient evidence to recommend for or against the use of devices promoted to make bed-sharing “safe.” There is no evidence that these devices reduce the risk of SIDS or suffocation or are safe. Some products designed for in-bed use (in-bed sleepers) are currently under study but results are not yet available. Bedside sleepers, which attach to the side of the parental bed and for which the CPSC has published standards, may be considered by some parents as an option. There are no CPSC safety standards for in-bed sleepers. The task force cannot make a recommendation for or against the use of either bedside sleepers or in-bed sleepers, because there have been no studies examining the association between these products and SIDS or unintentional injury and death, including suffocation.

3. Infants who are brought into the bed for feeding or comforting should be returned to their own crib or bassinet when the parent is ready to return to sleep.

4. Couches and armchairs are extremely dangerous places for infants. Sleeping on couches and armchairs places infants at extraordinarily high risk of infant death, including SIDS, suffocation through entrapment or wedging between seat cushions, or overlay if another person is also sharing this surface. Therefore, parents and other caregivers should be especially vigilant as to their wakefulness when feeding infants or lying with infants on these surfaces. Infants should never be placed on a couch or armchair for sleep.

5. The safest place for an infant to sleep is on a separate sleep surface designed for infants close to the parents’ bed. However, the AAP acknowledges that parents frequently fall asleep while feeding the infant. Evidence suggests that it is less hazardous to fall asleep with the infant in the adult bed than on a sofa or armchair, should the parent fall asleep. It is important to note that a large percentage of infants who die of SIDS are found with their head covered by bedding. Therefore, no pillows, sheets, blankets, or any other items that could obstruct infant breathing or cause overheating should be in the bed. Parents should also follow safe sleep recommendations outlined elsewhere in this statement. Because there is evidence that the risk of bed-sharing is higher with longer duration, if the parent falls asleep while feeding the infant in bed, the infant should be placed back on a separate sleep surface as soon as the parent awakens.

6. There are specific circumstances that, in case-control studies and case series, have been shown to substantially increase the risk of SIDS or unintentional injury or death while bed-sharing, and these should be avoided at all times:

   1. Bed-sharing with a term normal-weight infant younger than 4 months and infants born preterm and/or with low birth weight, regardless of parental smoking status. Even for breastfed infants, there is an increased risk of SIDS when bed-sharing if younger than 4 months. This appears to be a particularly vulnerable time, so if parents choose to feed their infants younger than 4 months in bed, they should be especially vigilant to not fall asleep.

   2. Bed-sharing with a current smoker (even if he or she does not smoke in bed) or if the mother smoked during pregnancy.

   3. Bed-sharing with someone who is impaired in his or her alertness or ability to arouse because of fatigue or use of sedating medications (eg, certain antidepressants, pain medications) or substances (eg, alcohol, illicit drugs).

   4. Bed-sharing with anyone who is not the infant’s parent, including nonparental caregivers and other children.

   5. Bed-sharing on a soft surface, such as a waterbed, old mattress, sofa, couch, or armchair.

   6. Bed-sharing with soft bedding accessories, such as pillows or blankets.

7. The safety and benefits of cobedding for twins and higher-order multiples have not been established. It is prudent to provide separate sleep surfaces and avoid cobedding for twins and higher-order multiples in the hospital and at home.

5. Keep soft objects and loose bedding away from the infant’s sleep area to reduce the risk of SIDS, suffocation, entrapment, and strangulation.

1. Soft objects, such as pillows and pillow-like toys, quilts, comforters, sheepskins, and loose bedding, such as blankets and nonfitted sheets, can obstruct an infant’s nose and mouth. An obstructed airway can pose a risk of suffocation, entrapment, or SIDS.

2. Infant sleep clothing, such as a wearable blanket, is preferable to blankets and other coverings to keep the infant warm while reducing the chance of head covering or entrapment that could result from blanket use.

3. Bumper pads or similar products that attach to crib slats or sides were originally intended to prevent injury or death attributable to head entrapment. Cribs manufactured to newer standards have a narrower distance between slats to prevent head entrapment. Because bumper pads have been implicated as a factor contributing to deaths from suffocation, entrapment, and strangulation and because they are not necessary to prevent head entrapment with new safety standards for crib slats, they are not recommended for infants.

6. Consider offering a pacifier at nap time and bedtime.

7. Avoid smoke exposure during pregnancy and after birth.

8. Avoid alcohol and illicit drug use during pregnancy and after birth.

9. Avoid overheating and head covering in infants.

10. Pregnant women should obtain regular prenatal care.

11. Infants should be immunized in accordance with recommendations of the AAP and Centers for Disease Control and Prevention.

12. Avoid the use of commercial devices that are inconsistent with safe sleep recommendations.

13. Do not use home cardiorespiratory monitors as a strategy to reduce the risk of SIDS.

14. Supervised, awake tummy time is recommended to facilitate development and to minimize development of positional plagiocephaly.

15. There is no evidence to recommend swaddling as a strategy to reduce the risk of SIDS.

16. Health care professionals, staff in newborn nurseries and NICUs, and child care providers should endorse and model the SIDS risk-reduction recommendations from birth.

17. Media and manufacturers should follow safe sleep guidelines in their messaging and advertising.

18. Continue the “Safe to Sleep” campaign, focusing on ways to reduce the risk of all sleep-related infant deaths, including SIDS, suffocation, and other unintentional deaths. Pediatricians and other primary care providers should actively participate in this campaign.

19. Continue research and surveillance on the risk factors, causes, and pathophysiologic mechanisms of SIDS and other sleep-related infant deaths, with the ultimate goal of eliminating these deaths altogether.

For more information about SIDS from the CDC and additional resources, please visit: cdc.gov/sids/