Sudden infant death syndrome (SIDS) is the sudden death of an infant <1 year of age that is unexplained after a systematic investigation of the case as well as performance of a full autopsy, investigation of the death scene and review of the medical history.
Risk factors include sleeping in prone or side position, male infants are more likely to be affected than female infants, perinatal period and beyond age 6 months, sleeping on soft surfaces or bedding, overheating or thermal stress, maternal smoking during pregnancy, young maternal age and pregnancy-related factors (eg inadequate or absence of prenatal care, higher birth order, preterm birth and/or low birth wt).