A sudden unexpected death in infancy (SUDI) is deemed to have occurred where there is no known pre-existing condition which would make the death predictable.
Infants may be discovered in their own cot or crib, sharing a sleep space such as an adult bed, sofa or chair, in their pram, car seat or infant carrier. Some infants may also suffer SUDI whilst sleeping in someone’s arms. SUDIs can occur during any sleep period not just a night time sleep.
SUDIs account for the largest number of infant deaths in those aged 2-6 months. There is a reduction in incidence beyond 12 months, with only a few cases per year in Scotland between 12-24 months.
Since the cause of death is not known, a death certificate cannot be issued and the death is not able to be registered. It is therefore routine practice that all SUDIs are reported to the Procurator Fiscal, on whose behalf the police will act. This practise is well established and the police will automatically be informed of the death by the Scottish Ambulance Service or Emergency Department. Investigations, which include a post-mortem examination may take several months and begins with the gathering of information from health workers and police. On the rare occasion when death appears to be the result of a criminal act, the police will work sensitively to collect detailed information from the outset.
All infant deaths which happen suddenly, and for which there is no apparent reason, are unexpected. From the outset all such causes are unknown (or unascertained), and therefore defined as SUDIs until more information is available.
In some cases a cause of death may be found during post-mortem examination, but for many the post-mortem examination will not explain the death. The term SUDI may therefore be given as a classification of death on the death certificate, as the death is still unexplained.
Once all ancillary post-mortem investigations are complete, cases may still remain unexplained. However pathology or circumstancial factors, for example social or parenting issues, may be highlighted as being present, although not causing the death. In these instances SUDI may be entered on a death certificate.
The term ‘Sudden Infant Death Syndrome’ (SIDS) is occasionally used where there is no pathology or risk factors present. The term is therefore a ‘diagnosis of exclusion’ rather than an actual cause of death in itself. SIDS cases can therefore be regarded as a subset of all SUDIs investigated.
‘Cot death’ is a popular description used for any of the above terminology. In particular, families who have lost an infant suddenly and unexpectedly may use this term.
For the purposes of this toolkit, the term ‘infant’ includes those aged from 0 -24 months.