Sudden Infant Death Syndrome (SIDS) and Related Infancy Fatalities

Comprehensive practice questions covering SIDS definitions, risk factors, pathogenesis, autopsy findings, prevention, and related legal/medical conditions such as SUID and non-accidental injury.

What is the definition of Sudden Infant Death Syndrome (SIDS)?

The sudden death of an infant under 1 year of age which remains unexplained after a thorough case investigation, including a complete autopsy, death scene examination, and clinical history review.

At what age does the peak incidence of SIDS occur?

3 - 4 months.

How did the incidence of SIDS in the UK change between the 1990s and the time the notes were written?

It fell from 2 per 1000 live births in the 1990s to 0.5 per 1000 live births.

What are the three components of the Triple Risk Model for SIDS pathogenesis?

1. Vulnerable infant, 2. Critical developmental period in homeostatic control, 3. Exogenous stressors.

Which parental risk factors are associated with SIDS?

Young maternal age (younger than 20 years), maternal smoking during pregnancy, drug abuse (paternal marijuana and maternal opiate or cocaine use), short intergestational intervals, late or no prenatal care, and low socioeconomic group.

What infant characteristics are identified as risk factors for SIDS?

Brain stem abnormalities, prematurity and/or low birth weight, male sex, product of a multiple birth, SIDS in a prior sibling, and antecedent respiratory infections.

List the environmental risk factors for SIDS.

Prone or side sleep position, sleeping on a soft surface, hyperthermia, and co-sleeping in the first 3 months of life.

Which specific genetic mutations are associated with Long QT syndrome in cases of Sudden Unexpected Infant Death (SUID)?

$SCN5A$ and $KCNQ1$ mutations.

What are the common non-specific morphology findings at autopsy for SIDS?

Gastric contents in the mouth and upper airways, multiple petechiae (thymus, visceral and parietal pleura, epicardium), congested lungs with pulmonary oedema, and subtle changes in brain stem neurones.

What percentage of Sudden Unexpected Death in Infancy (SUDI) cases remain unexplained?

85%.

According to the transcript, what are the seasonal peaks for SIDS?

Winter, early spring, and late autumn.

What are the specific environmental prevention measures for SIDS regarding bedding?

Infants should sleep in a supine position (back to sleep program), avoid soft surfaces (no pillows, comforters, quilts, sheepskins, or stuffed toys), and use sleep sacks in place of blankets.

How does Non accidental injury (NAI) typically present compared to SIDS?

It tends to occur in an older age group (fatalities common under 2 years), often presents during the day as a sudden "collapse," involves multiple injuries of varying ages, and may show a delay in seeking medical assistance.

What physical injury patterns are associated with Non accidental injury?

Multiple bruises and fractures of varying ages, subdural haemorrhage, retinal haemorrhage and detachment, torn frenulum (oral injury), and ruptured bowel or liver (visceral injury).

What is the definition of infanticide according to Section 203 of the Penal code act?

When a woman by any wilful act or omission causes the death of her child under the age of twelve months while the balance of her mind was disturbed by reason of not having fully recovered from the effect of giving birth or the effect of lactation.

Which metabolic defects are noted as potential genetic causes for SUID?

Fatty acid oxidation disorders ($MCAD$, $LCHAD$, $SCHAD$ mutations) and Histiocytoid cardiomyopathy ($MTCYB$ mutations).

What microbiological investigations are recommended in cases of sudden infant death?

Blood and spleen swabs.