Definition

There have been many definitions to describe the sudden and unexpected death of an infant or child. Most exclude deaths in the first week and after the first year.

Most people use the term sudden unexpected death in infancy (SUDI) to mean a death that was not anticipated as a significant possibility 24 hours before the death. It would include deaths occurring as a result of an acute illness not anticipated 24 hours before the death, deaths arising from a previously known condition not expected to lead to death, or deaths arising from a pre-existing condition not previously recognized. It usually includes those deaths resulting from accident, trauma, or poisoning.

The cases where the cause of death is not known after a full and detailed history, death scene investigation, full pathology using a standardized protocol, and multi-agency review are then described as sudden infant death syndrome (SIDS). Of course, if a cause is found then the death does not belong to the category of SIDS.

The diagnosis of SIDS should not be used unless there is a full post mortem with no positive findings.

The term cot death was used in the past. This is no longer a useful term as the majority of infants are not found in the cot and some parents believe that if the child is not in its cot it will not be a cot death.