FFinalistSouthampton · 2027
Child health
AKT · Child health/Neonatal & surgical

Sudden infant death syndrome (SIDS)

Sudden unexplained death of an infant — modifiable risk factors

Overview

The sudden, unexpected death of an apparently well infant (peak 2–4 months) that remains unexplained after investigation. Several risk factors are MODIFIABLE — the "Back to Sleep" advice. A new death is also a safeguarding consideration.

Recognise

  • Peak age 2–4 months; commoner in boys, winter, low birth weight/prematurity
  • Major modifiable risks: PRONE/side sleeping, parental SMOKING (antenatal & postnatal), CO-SLEEPING (especially with alcohol/drugs or on a sofa), overheating/head covering
  • Protective: SUPINE sleep, room-sharing (not bed-sharing), breastfeeding, dummy/pacifier use, avoiding smoke/overheating

Red flags

  • Features inconsistent with the history, multiple/previous unexplained infant deaths, or signs of injury → safeguarding (consider non-accidental injury)

Differentials & how to tell them apart

Non-accidental injury (abuse)inconsistent history, injuries, prior concerns — must be excluded
Overwhelming sepsis / metabolic diseasefound on SUDI work-up / post-mortem
BRUE (brief resolved unexplained event)the infant recovers — not a death; assess risk and admit if higher-risk

Investigations

Sudden unexpected death in infancy (SUDI) protocol: joint paediatric/police investigation, post-mortem, review of history and scene — to identify explained causes and safeguarding concerns.

Management

Prevention: "Back to Sleep" — supine, feet-to-foot, no smoking, no sofa/bed-sharing, avoid overheating

  1. 1Prevent: advise supine sleep, baby in own cot in the parents’ room for 6 months, smoke-free, avoid co-sleeping (never on a sofa or after alcohol), avoid overheating.Gate: Any death where the history does not fit, or there are injuries/prior concerns → safeguarding referral and SUDI investigation
  2. 2After a death: SUDI protocol (joint agency), bereavement support, and consideration of risk to siblings.
No drug — prevention by safe-sleep advice — risk-reduction counselling at every contact

Key points

Bed-sharing risk is greatly amplified by parental smoking, alcohol/drugs, or sleeping on a sofa. Every unexpected infant death triggers a joint investigation — partly bereavement, partly safeguarding.

Monitor & prognosis

Bereavement support; sibling risk review.

Incidence fell sharply after the 1991 Back to Sleep campaign.

Source: The Lullaby Trust; NICE (safe sleeping); RCPCH SUDI guidance