What is sudden infant death syndrome (SIDS)?Sudden infant death syndrome (SIDS) (also called crib death) is the sudden and unexplained death of an infant baby under 1 year of age. SIDS is sometimes called crib death because the death occurs when a baby is sleeping in a crib. It is the major cause of death in babies from 1 month to 1 year of age. The death is sudden and unpredictable; in most cases,
the baby seems healthy. Death occurs quickly, usually during a sleep time. SIDS strikes suddenly and silently, usually at night. Typically, a peacefully sleeping baby simply never wakes up. In most cases, no cause is ever found, and the death is best described as a sudden infant death syndrome death. The condition rarely occurs before 2 weeks or after 6 months of age. Most deaths occur in children who are between 2 months and 4 months of age.
Sudden infant death syndrome is a definition of exclusion and only applies to an infant whose death remains unexplained after the performance of an adequate postmortem investigation including (1) an autopsy, (2) investigation of the scene and circumstances of the death and (3) exploration of the medical history of the infant and family. Generally, but not always, the infant is found dead after having been put to sleep and exhibits no signs of having suffered. The inexplicable nature of the syndrome often leaves parents with a deep sense of guilt in addition to their grief. Sudden infant death syndrome is more common in premature infants, those who were small at birth, those that previously needed resuscitation, and those with upper respiratory tract infections. For unknown reasons, Black and American Indian infants are at a higher risk. It is more common among infants in families with low incomes, whose mothers are single or who used cigarettes or illicit drugs during pregnancy, and who had brothers or sisters who also died of sudden infant death syndrome.