Overview of SIDS

Sudden infant death syndrome (SIDS) is the unexplained, unexpected death of a baby less than one year old. Because SIDS usually occurs when the infant is sleeping, it is sometimes called "crib death." Sudden infant death syndrome is the leading cause for death in babies under the age of 1 year. Most SIDS deaths occur between the ages of 4 and 6 months of age.

SIDS can occur in babies that seem perfectly healthy. In many circumstances, the parent or caregiver puts the baby down to sleep and later discovers that he or she has died. There are no warning signs and infants who die from SIDS show no signs of suffering.

SIDS usually is diagnosed after all other possible causes of death have been investigated and ruled out. Doctors perform an autopsy, examine the infant's medical history, and evaluate the baby's home environment.

SIDS deaths are devastating for family members. Because doctors cannot explain why the baby has died, families are left wondering what they could have done differently. Grief counseling and support services often are necessary.

Incidence of SIDS

Approximately 2,500 babies die from sudden infant death syndrome every year in the United States. SIDS affects African American infants twice as often as Caucasians, and Native American infants are three times more likely to die of SIDS than Caucasians.

Worldwide statistics on SIDS incidence vary. The World Health Organization (WHO) lists statistics for member countries for the last years that data were available. For example, in Argentina in 2001, 301 out of 11,111 deaths of infants younger than one year were attributed to SIDS. In Japan in 2002, SIDS resulted in 253 out of 3,497 infant deaths. In Kuwait in 2002, 8 out of 418 infant deaths occurred as a result of SIDS.

Incidence of SIDS is higher in babies who are placed to sleep on their stomachs and those who are born to mothers who smoked during pregnancy. Sudden infant death syndrome affects boys more often than girls and occurs more frequently in cold weather.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 28 Aug 2008

Last Modified: 18 Nov 2011