Or Cot death? Or SIDS (Sudden infant death syndrome)?
It is well recognised that some babies go to sleep apparently healthy, and then don’t wake up in the morning. Even after a full post mortem (PM) investigation, no cause is found. This unexplained phenomenon however has some very well recognised features eg age 2-6 months, prematurity, maternal smoking, poor socio-economic conditions, prone sleeping.
SUDI was originally defined by CESDI (Confidential Enquiry into Stillbirths and Deaths in Infancy) as death between 7 and 365 days where unexpected and unexplained at autopsy, during an acute illness that was not recognised as life-threatening, due to an acute illness of less than 24 h duration in a previously healthy infant (or death after this if life had only been prolonged by intensive medical care); definition also includes deaths from a pre-existing occult condition, and deaths from any form of accident, trauma or poisoning.
I find SUDI most useful for describing the initial situation one may find oneself in, particularly from the point of view of bereavement, need for medical and police investigation. Interestingly, many of the same risk factors pertain to both deaths unexplained (ie SIDS, or strict SUDI) and to accidental deaths (with the exception of prone sleeping).
SIDS is the ICD recognized term, so is what is generally put on a death certificate. However pathologists vary in their use of the terminology, some will use “Unascertained” to mean SIDS, others will use SIDS but reserve Unascertained for cases where there are additional factors that somehow cast doubt on the diagnosis.
Similarly, overlying (smothering) as a cause of SUDI is often inferred from the history, but may be specified on the death certificate to differentiate from SIDS.
PM finds a cause in about a 1/3 of cases) eg
- Infection
- Cardiomyopathy, anomalies of coronaries
- Ion channelopathies
- Metabolic disorders eg MCAD
See also Prevention, and Sudden unexpected postnatal collapse.