Defined as sudden death of an infant younger than 1 year of age that is unexplained after autopsy, examination of the death scene, and review of the clinical history.
For more than 10% of pediatric deaths, a specific cause of death is not established. despite autopsies and investigations.
Rates of unexplained deaths among infants is currently 90.1 per hundred thousand live births.
The major cause of death in infants between 1 month and 1 year.
Most deaths occur within the first 8 months and the majority around 3-4 months and the fewest in the first month.
The risk is higher for males, preterm and low birth weight infants.
No pathognomonic autopsy findings.
Defective signaling of serotonin in the brain may be related to the sudden infant death.
It is suggested that serotonin and other neurotransmitter abnormalities in the brain stems of infants who died from SIDS, are associated with failures in auto resuscitation and arousal.
It is estimated that causative genetic variants contribute to death in 11% of cases of infants who die from SIDS.
Incidence 0.7 deaths/1000 live births for the first sibling and a relative risk of 5 for recurrence.
Overall rate in the U.S. 0.54 per 1000 live births.
SIDS parents considering another pregnancy can expect that 99.65% of subsequent sibling will survive infancy.
The prone sleeping position is the major risk factor.
Decreased arousal from sleep in the prone position.
Abandonment of the prone position for sleeping infants has been associated with a decrease in incidence of almost 50%.
Despite initial success, overall death rate has reached a plateau over the last decade.
Bedsharing is associated with a younger age at death.
Younger siblings of babies who died from SIDS are four times as likely as other babies to also die from SIDS.
The risk of SIDS among first through third degree relatives is nine times as high as the risk in non-affected families.
A substantial number infants dying of SIDS (30-70%) have moved within their sleep space in such a manner as to allow their faces and/or heads to become covered by bed clothing.
In the developed world it is responsible form more infant deaths beyond the neonatal period than any other cause.
Other risk factors include unstable side sleeping, use of soft pillows and duvets, maternal smoking and second hand smoking.
Associated with low socioeconomic groups, unemployed single mothers younger than 20 years of age, preterm births of a first male infant and less common use of breast feeding.
Higher risk in large families.
Triple risk model suggests: underlying vulnerability, critical developmental period and an exogenous stress (Filiano JJ).