cot death Sudden unexpected death, with no cause identified after post-mortem examination, accounts for between one-third and one-half of deaths occurring in babies between the ages of 1 month and 1 year in developed countries.

In 1855, Thomas Wakely, the founder editor of the Lancet, wrote about ‘Infants found dead in bed’. At that time infanticide was common and accounted for over 80% of all coroner's reports of murder in England and Wales. Disraeli said that infanticide was ‘hardly less prevalent in England than on the banks of the Ganges’. Deaths from unintended smothering were also common, perhaps because of overcrowding in bed and the prevalence of drunkenness.

There was a period during the first half of the twentieth century when cot deaths were mistakenly attributed to the enlargement of the thymus gland (part of the immune system, found in the upper chest and lower neck). Pathologists, inexperienced in childhood post-mortems, would attribute the death of these infants to a disease, which they called status thymo-lymphaticus. Surgical removal of the thymus as a prophylactic measure became quite fashionable. Thymus enlargement is now known to be normal in this age group, and the erroneous theory, like many postulated before and after this time, gradually fell into disrepute.

During the 1940s the concept of ‘cot death’ became more clearly defined, but it was not until 1969, at the second conference on causes of Sudden Deaths in Infants, that cot death was defined as ‘any sudden death of an infant or young child, which is unexpected by history and for which a thorough post-mortem examination fails to demonstrate an adequate cause of death’. Most forensic post-mortems in the UK are now performed by experienced paediatric pathologists and more accurate records of the prevalence of what is now know as Sudden Infant Death Syndrome (SIDS) have been available in the UK during the past 25 years. The rate of cot deaths during this time has reduced from about 2.3 to 1.3 per thousand live births — that is about 10 deaths per week. This improvement may have been due to changes in behaviour in response to four identified risk factors for babies: (i) being placed face down to sleep; (ii) having a mother who smokes cigarettes; (iii) not being breastfed; and (iv) sharing the bed with parents.

Because of remaining uncertainty as to the cause of SIDS, many other theories have been put forward. Hyperthermia (over-heating), due to an excessively heated bedroom or too many bed coverings, may be involved. Unidentified infections remain an unproven cause, and they might also contribute to hyperthermia. Another suggested cause is exposure to noxious chemicals. For a time there was a theory that fungi attacked the coverings of cot mattresses, releasing trace amounts of toxins such as arsenic and antimony, but this idea has now been discredited. It is likely that, as further information is acquired, a number of different contributory factors will be identified.

The sudden loss of an apparently healthy baby causes enormous anguish in parents and results in inevitable feelings of guilt and fear about the outcome of future pregnancies. Groups of affected families have established support organizations and have raised funds to sponsor research.

Ann Dally, and Forrester Cockburn

cot death (sudden infant death syndrome, SIDS) (kot) n. the sudden unexpected death of an infant less than two years old (peak occurrence between two and six months) from an unidentifiable cause. There appear to be many factors involved, the most important of which is the position in which the baby is laid to sleep: babies who sleep on their fronts (the prone position) have an increased risk.
www.fsid.org.uk Website of the Foundation for the Study of Infant Death

cot death (sudden infant death syndrome) Sudden, unexpected death of an infant less than two years old. In the UK, it accounts for c.20% of infant mortality. It appears that the most important factor is the position in which the infant sleeps: babies who sleep on their fronts have an increased risk.