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Sudden Infant Death Syndrome (SIDS)

Baby blocks spelling out SIDSOctober is SIDS Awareness Month. Learn about infant deaths from SIDS and other causes, and take action to reduce the risk. Start by always placing babies on their backs when putting them to sleep.

Understanding the Problem

About 3,500 infants died suddenly and unexpectedly in 2014 in the United States. These deaths are called sudden unexpected infant deaths (SUID). The most common types of SUID include:

  • Sudden Infant Death Syndrome (SIDS)
    The sudden death of an infant less than 1 year old that cannot be explained after a thorough investigation that includes a complete autopsy, examination of the death scene, and a review of the medical history. About 1,500 infants died of SIDS in 2014. SIDS is the leading cause of death for infants aged 1 to 12 months.
  • Unknown Cause
  • The sudden death of an infant less than 1 year old that remains undetermined because one or more parts of the investigation was not completed.

    Safe to Sleep

    CDC is working with the National Institutes of Health in its Safe to Sleep campaign, formerly known as the Back to Sleep campaign. The Safe to Sleep campaign has outreach and education activities aimed at reducing infant death from SIDS and other sleep-related causes.

  • Accidental Suffocation and Strangulation in Bed (ASSB)
    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.
    • 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 get caught between crib railings.
	Mother putting infant to rest in crib

Always place babies on their backs every time you put them to sleep.

	Karin and Jonathan’s older sister

Karin and Jonathan's older sister

Reducing the Risk

Doctors and researchers don't know the exact causes of SIDS. However, research shows that parents and caregivers can take the following actions to help reduce the risk of SIDS and other sleep-related causes of infant death:

  • Always place babies on their backs when putting them to sleep for naps and at night.
  • Use a firm sleep surface, such as a mattress in a safety-approved crib, covered by a fitted sheet.
  • Share your room with your baby, not your bed. Your baby should not sleep in an adult bed, on a couch, or on a chair alone, with you, or with anyone else.
  • Keep soft objects, such as pillows and loose bedding, out of your baby's sleep area.
  • Do not smoke during pregnancy or around the baby because these are strong risk factors for SIDS. The risk of SIDS is even greater when a baby shares a bed with a smoker. To reduce risk, do not smoke during pregnancy, and do not smoke or allow smoking around your baby. For help in quitting, call the quitline at 1-800-QUIT-NOW (1-800-784-8669) or visit smokefreewomen.

See Ways to Reduce the Risk of SIDS and Other Sleep-Related Causes of Infant Death to learn more about these and other actions.

Learn about safe sleep environments and reducing the risk of SIDS and other sleep-related infant deaths by reading What Does a Safe Sleep Environment Look Like? [PDF - 336KB].

In addition, CDC supports the recommendations issued by the American Academy of Pediatrics (AAP) to reduce the risk of sleep-related infant deaths, including SIDS. Learn more at the Healthy Children website, sponsored by AAP.

Improving Our Understanding of SIDS and SUID

Sudden Unexpected Infant Death and Sudden Death in the Young Case Registries

CDC's Division of Reproductive Health has SUID monitoring programs in 16 states and 2 jurisdictions, covering 30% of all SUID cases in the United States. Participating states and jurisdictions use data about SUID trends and circumstances to inform strategies to reduce future deaths. The SUID Case Registry builds on the National Center for Fatality Review and Prevention System and brings together information about the circumstances associated with SUID cases, as well as information about investigations into these deaths. CDC and the National Institutes of Health collaborate on the Sudden Death in the Young (SDY) Case Registry, which expands the population of the SUID Case Registry from infancy through adolescence.

SUID Prevention in Action: A Story from New Jersey

Karin's baby Jonathan was 2 months old when she arrived at Neptune, New Jersey's Child Care Resources Center. With the support from New Jersey's SUID prevention activities, Karin received safe sleep education and a portable crib for Jonathan. "My baby now has a place of his own to sleep tonight."