Snapshot A 5-month-old boy is brought to the emergency department by his parents after being found to be unresponsive and not breathing in the morning. The parents say the infant was properly fed prior to sleep. They have a baby monitor in the babies room and they did not note any crying throughout the night. When they found the baby, his fists were clenched and there was mucoid discharge from the nose. On physical exam the infant is unresponsive and his skin was mottled. An extensive investigation is conducted and preparations are made for an autopsy. Introduction Definition sudden death at < 1 year of age that is unexplainable after a thorough investigation Epidemiology Incidence leading cause of infant mortality between the ages of 1 month and 1 year in the United States Risk factors sleeping in the prone or side position bed sharing smoke exposure during pregnancy prematurity or low birth weight bedding accessories such as pillows loose blankets Etiology It is multifactorial Presentation Symptoms and physical exam typically a < 6-month-old healthy infant who is found to be unresponsive and not breathing after sleeping in bed/crib DIAGNOSIS Making the diagnosis this is a diagnosis of exclusion no known cause is found after an extensive investigation (e.g., autopsy) Treatment Conservative support the family