1. Rachel Y. Moon, MD* 2. Linda Y. Fu, MD, MSc† 1. *Director, Academic Development, Goldberg Center for Community Pediatric Health, Children's National Medical Center, Washington, DC 2. †Assistant Professor of Pediatrics, Goldberg Center for Community Pediatric Health, Children's National Medical Center, Washington, DC After completing this article, readers should be able to: 1. Describe possible etiologic mechanisms for sudden infant death syndrome (SIDS). 2. Identify the risk factors for SIDS. 3. Understand the relationship between apnea and SIDS. 4. Discuss the American Academy of Pediatrics SIDS Task Force recommendations and underlying rationale. Sudden infant death syndrome (SIDS) is defined as the sudden unexplained death of an infant younger than 1 year of age. It usually occurs in a previously healthy infant, and the cause of death remains unexplained despite a thorough case investigation, including a complete autopsy, death scene investigation, and review of the clinical history. Every year in the United States, approximately 2,500 infants die from SIDS. Risk factors have been identified through epidemiologic studies. SIDS is more likely to occur in male infants (3:2 ratio). Other risk factors include prone and side sleeping positions, maternal smoking during pregnancy, environmental tobacco smoke, overheating, soft bedding, inadequate prenatal care, young maternal age, prematurity or low birthweight, and African-American or American Indian/Alaskan Native heritage. For many years, apnea was believed to be the predecessor of SIDS, and home apnea monitors have been used in an attempt to prevent SIDS. However, studies such as the Collaborative Home Infant Monitoring Evaluation (CHIME) have demonstrated that apnea neither precedes nor predicts SIDS. Although apnea monitors may be useful in selected patients who have experienced apparent life-threatening events (ALTEs), there is no evidence that they are useful in reducing the risk of SIDS, and the American Academy of Pediatrics (AAP) recommends against using monitors as a SIDS prevention technique. (A more detailed discussion of ALTEs appears in this issue of Pediatrics in Review on page 203.) In 1992, the AAP first published its recommendation that infants should sleep in a nonprone position to reduce the risk of SIDS, and a national public …