Facts About SUDC

  • Sudden Unexplained Death in Childhood (SUDC) is the sudden and unexpected death of a child, between 1 and 18 years of age, which remains unexplained after a thorough case investigation is conducted. This must include; examination of the death scene, performance of a complete post-mortem, and a review of the child and family’s medical history (Medically defined by Krous et al in 2005). 
  • SUDC is a category of death that eludes our scientific understanding today.
  • We do not currently know of any way to reduce the risk of Sudden Unexplained Death in Childhood.
  • At this time, no-one can predict or prevent these deaths; neither parents nor medical professionals.

Statistics in the UK

Variation in investigation and certification mean we do not know exactly how often SUDC occurs. The lack of a single, specific code for the sudden and unexplained death of a child, and limited awareness, means a range of terms are used in these cases. For more information on terminology please visit our webpage on the child death process.

Currently the best way to estimate the incidence of SUDC, is to examine a range of data for  ‘ill-defined and unknown causes of mortality’- World Health Organisation ICD-10 codes R95-99. 

40 children

ONS data indicates:

  • Approximately 40 children in the UK are affected by SUDC each year.
  • Sudden Unexplained Death In Childhood is the the 5th leading category of death for children aged 1-4 years.
  • There are more young unexplained childhood deaths (at 1-9 years of age) than deaths due to traffic accidents, fires or drowning. 

This chart displays the number of unexplained child deaths over recent years in England and Wales reported by the Office of National Statistics (ONS). The data is visually separated out by year and columns divided by age. Due to inconsistencies in certification, it is not advisable to draw conclusions about a change in the incidence of SUDC over time. However, it shows the numbers are variable with a range of 27-55 cases reported in a single year; comparable to 1-2 children dying every fortnight. The median number of deaths in one year over this time period is 42.

Sudden Unexplained Death in Childhood can affect children of any age from 1-18. However, it appears to be most prevalent in toddlers and children in their late teens. This distribution of deaths is consistent with international data.

Most recent ONS data:  2020

35 child deaths were reported as ICD-10 codes R96-R99 in England and Wales in 2020:

  • 19  one-four year olds
  • 2   five-nine year olds
  • 4    ten-fourteen year olds
  • 10  fifteen-nineteen year olds

Additional data sources report:

  • 3 children were affected in Scotland (National Records of Scotland)
  • 1 child was affected in Northern Ireland (Northern Ireland Statistics and Research agency)

Further information

  • In England and Wales in 2020 there were 325 deaths of children aged 1-4 years and 5.4% of these were sudden and unexplained.
  • SUDC is rare, with a crude death rate of 0.7 per 100,000 for the age range most commonly affected (children aged 1-4 years).


Profile of a child affected by SUDC

Published epidemiological data suggests the following profile for a child affected by SUDC:

  • Most often between 1 and 2 years of age
  • Most often the child is male
  • Died an unwitnessed death during apparent sleep
  • In nearly all cases children are found prone (sleeping on their front) 
  • Approximately half have an illness or terminal fever which cannot explain the death
  • The child’s development is usually within normal limits and vaccinations are up to date 
  • There is also published evidence to suggest an association between febrile seizures and SUDC with a higher proportion of families reporting a history of febrile seizures than is known to occur in the general population (For example, 28.8% vs 2-5% reported in Crandall et al, 2019)


  • Crandall et alLG, Lee JH, Stainman R, Friedman D, Devinsky O. Potential Role of Febrile Seizures and Other Risk Factors Associated With Sudden Deaths in Children. JAMA Netw Open. 2019 

  • Hefti MM, Kinney HC, Cryan JB, Haas EA, Chadwick AE, Crandall LA, Trachtenberg FL, Armstrong DD, Grafe M, Krous HF. Sudden unexpected death in early childhood: general observations in a series of 151 cases: Part 1 of the investigations of the San Diego SUDC Research Project. Forensic Sci Med Pathol. 2016 

  • Hesdorffer DC, Crandall LA, Friedman D, Devinsky O. Sudden unexplained death in childhood: A comparison of cases with and without a febrile seizure history. Epilepsia. 2015 

  • McGarvey CM, O’Regan M, Cryan J, Treacy A, Hamilton K, Devaney D, Matthews T. Sudden unexplained death in childhood (1-4 years) in Ireland: an epidemiological profile and comparison with SIDS. Arch Dis Child. 2012 

For more detailed information please see published research on SUDC or contact us

Hope for the future

The advocacy work of SUDC UK, current global research projects and the new National Child Mortality Database in England will hopefully provide more accurate information on this category of death. We hope this will help encorrage appropriate urgency for investigating, understanding and preventing SUDC. 

Sudden Unexplained Death in Childhood is not restricted to the UK and more information from the WHO and CDC database is available from the SUDC Foundation website. In 2019, similar analysis estimates 342 children were affected by SUDC in the U.S.