Many terms can be used to describe babies who die suddenly and unexpectedly during sleep in whom the cause cannot be determined. These include terms like SIDS, SUID, Undetermined, and Accidental. This may be confusing, especially if different terms may appear to describe the same tragedy: an unexplained and unexpected infant death. For this reason, and because the “SIDS” is the most recognizable term for the general public, we have decided to use the term “SIDS” to describe all of these babies.
Here are some more specific definitions to help sort through this confusion:
- Sudden Unexpected Infant Death (SUID): The death of an infant younger than 1 year of age that occurs suddenly and unexpectedly. Causes may include occurrences such as:
- Suffocation: When no air reaches a baby’s lungs, usually caused by a block in the airway
- Entrapment: When a baby gets trapped between two objects, such as a mattress and wall, and can’t breathe
- Strangulation: When something presses on or wraps around the infant’s head and neck blocking the airway.
- Infection: When a baby has a cold or other infection caused by a virus or bacteria that makes breathing difficult
- Ingestion: When a baby takes something into the mouth that blocks the airway or causes choking
- Metabolic diseases: Conditions related to how the body functions that can lead to problems with breathing
- Cardiac arrhythmias: When a baby’s heart beats too fast or too slow and affects breathing
- Trauma (accidental or non-accidental): When a baby experiences an injury
- SIDS (see below)
- Undetermined: In some cases, the evidence is not clear or not enough information is available, so the death is considered to be of undetermined cause.
- Sudden Infant Death Syndrome (SIDS): One type of SUID, SIDS is the sudden death of an infant younger than 1 year of age that cannot be explained even after a full investigation that includes a complete autopsy, examination of the death scene, and review of the clinical history.
- Accidental Suffocation and Strangulation in Bed (ASSB): One type of SUID, ASSB is a cause-of-death code used for vital statistics purposes. Examples of ASSB include:
- Suffocation by soft bedding: When soft bedding, a pillow, or a waterbed mattress blocks the infant’s airway.
- Overlay: When another person shares the sleep surface with the infant and lays on or rolls on top of or against the infant while sleeping, blocking the infant’s airway.
- Wedging or entrapment: When an infant gets trapped between two objects, such as a mattress and wall, bed frame, or furniture, blocking the infant’s airway.