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Sudden Unexpected Infant Death (SUID)

Each year in the United States, more than 4,500 infants die suddenly of no obvious cause. Half of these Sudden Unexpected Infant Deaths (SUID) are due to Sudden Infant Death Syndrome (SIDS), the leading cause of SUID and of all deaths among infants aged 1–12 months.

If you or someone you know has experienced the loss of a baby, whether during pregnancy or after birth, visit
First Candle—SIDS Alliance*

Sudden Infant Death Syndrome (SIDS)

Sudden Infant Death Syndrome (SIDS) is defined as the sudden death of an infant less than one year of age that cannot be explained after a thorough investigation is conducted, including a complete autopsy, examination of the death scene, and review of the clinical history.

SIDS is the leading cause of death among infants aged 1–12 months, and is the third leading cause overall of infant mortality in the United States. Although the overall rate of SIDS in the United States has declined by more than 50% since 1990, rates have declined less among non-Hispanic Black and American Indian/Alaska Native infants. Preventing SIDS remains an important public health priority.

Help For Families When An Infant or Young Child Dies* Sudden Unexplained Death in Childhood (SUDC) Program. This brochure outlines for families—

How the medical examiner and coroner process works.
Defines the roles of the professionals that may be involved.
Provides time estimates for the investigation process.
Provides national resources.

Examples of different types of SUID are SIDS, suffocation, poisoning, falls, and others graphic.

For a medical examiner or coroner to determine the cause of the death, an investigator needs to conduct a thorough investigation including examination of the death scene and a review of the infant’s clinical history. A complete autopsy needs to be performed, ideally using information the investigator has gathered. Even when a thorough investigation is conducted, it may be difficult to separate SIDS from other types of sudden unexpected infant deaths, especially accidental suffocation in bed.

Sudden unexpected infant deaths are defined as infant deaths that occur suddenly and unexpectedly, and whose manner and cause of death are not immediately obvious prior to investigation.

After a thorough death scene investigation, review of medical records and a complete autopsy, many of these sudden unexpected infant deaths may be explained. Poisoning, metabolic disorders, hyper or hypothermia, neglect and homicide, and suffocation are all explainable causes of SUID. SIDS and cause unknown are examples of those that remain unexplained SUID.