Sudden Unexpected Infant Death Cause of Death


Sudden Unexpected Infant Death (SUID) is NOT a cause of death. SUID includes SIDS and is a category of deaths. It includes deaths among infants less than 1 year of age that occur suddenly and unexpectedly, where the cause of death is not immediately obvious prior to investigation. SUID should never be written on a death certificate. 


By correctly documenting the cause of death, we can learn more about the differences in risk factors among infants who died from SIDS and other causes. We can more efficiently allocate resources and create targeted interventions to prevent future deaths. 

Note: Unless there is a confirmed SIDS case, DO NOT use any combination of the following words on a death certificate. Vital Records will inappropriately classify the death as SIDS if any of the following combination of words are used. 


Any time the documented cause of death is any combination of the following words, the computer codes the death as Sudden Infant Death Syndrome (SIDS) in vital records data:

  • Infant
  • Unexpected
  • Unexplained
  • Sudden
  • Death
  • Syndrome

Please help us correctly document the cause of death on the death certificate by following the guidance listed below:



Unknown or

The death cannot be explained and one of the following is unavailable: autopsy, death scene investigation or review of clinical history.

Accidental Suffocation
and Strangulation in
Bed (ASSB)

The death occurred in a sleep environment and may be due to overlay or roll over. The death may also be due to an object in the sleep environment including but not limited to bed linens, sheets, blankets, pillows, stuffed animals, or soft bedding.

Sudden Infant Death
Syndrome (SIDS)

The death of an infant less than 1 year of age cannot be explained even after autopsy, death scene investigation and review of clinical history. All criteria must be met in order to classify the death as SIDS.


Download the Coroner's Guide here.