sids

Sudden infant death syndrome (SIDS) is the sudden, unexpected death of an infant less than one year old that remains unexplained after a thorough investigation, including a complete autopsy, examination of the death scene, and review of the clinical history. SIDS is a diagnosis of exclusion and a subset of sudden unexpected infant death (SUID).

Most SIDS deaths occur during sleep, typically in infants aged two to four months, with a higher risk in males. Risk is elevated by prenatal tobacco exposure, postnatal smoke exposure, prematurity, and other factors, though SIDS can occur in any infant.

Key risk factors include sleeping on the stomach or side, sleeping on a soft surface or with soft bedding, overheating or overbundling, bed-sharing with adults or siblings, and lack of exclusive breastfeeding. Other associations include a family history of SIDS, young maternal age, and inadequate prenatal care. Safe sleep campaigns have contributed to declines in SIDS rates in many regions.

Prevention centers on safe sleep practices: always place the infant on the back to sleep on a firm, flat sleep surface; keep the sleep area free of pillows, loose bedding, bumper pads, and stuffed toys; avoid bed-sharing and overheating; room-share without bed-sharing; breastfeed if possible; consider offering a pacifier at nap and bedtime after breastfeeding is established; avoid exposure to tobacco, alcohol, and illicit drugs during pregnancy and after birth.

Diagnosis is by exclusion; there is no definitive test for SIDS. A complete autopsy and a death-scene investigation are typically required to classify a death as SIDS and to rule out other causes.

Research continues into the biological factors underlying SIDS, including brainstem regulation of breathing and arousal, and the development of risk-screening tools.