# Sudden infant death syndrome and sleep-related infant death Condition · id `maternal:sudden-unexpected-infant-death` · Maternal & Newborn Atlas · release `c7fb95f1d15a7d13` (public) > General information from published sources, not medical advice, and not reviewed by clinicians. Check the cited source before relying on anything here. The atlas's own text and curation may be reused under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/): credit the atlas, and do not use it commercially. See the atlas About page. Text quoted from a source stays under that source's own terms, given as the source's reuse\_basis. The atlas's reuse terms do not cover it. The downloads list each quotation with its source in third\_party\_quotations. Browse, life stage: Infant follow-up Browse, care area: The baby's first year ## In plain language Sometimes a baby younger than one year dies suddenly and unexpectedly. When a full investigation finds no cause, the death is called sudden infant death syndrome (SIDS). Safe sleep steps can lower the risk. Sleep itself does not cause SIDS. ## Technical summary NICHD defines SIDS as the sudden death of a baby younger than 1 year that has no known cause even after a full investigation (complete autopsy, examination of the death scene and review of the clinical history). Sudden unexpected infant death (SUID) is the umbrella category for all sudden, unexpected infant deaths, whether from a known cause such as an injury or accident or an unknown cause such as SIDS. About 3,000 SUIDs occur in the United States each year, and more than 1 in 3 are SIDS (see the claim on this page). MedlinePlus says the cause of SIDS is unknown, that it is the leading cause of death between one month and one year, and lists steps to reduce risk. MedlinePlus and NICHD both list feeding human milk among the steps that lower the risk. The recipient is the infant. ## Claims, with the population each applies to ## Context: Infants younger than 1 year in the United States and their caregivers (NICHD Safe to Sleep) Recipient: Child; Population: Babies younger than 1 year of age and the people who care for them. The Safe to Sleep campaign addresses parents, grandparents, other relatives, babysitters, child care providers and anyone who might care for a baby. Counts on the page are for the United States.; Care setting: Home and child care sleep settings (the page lists parents, babysitters and child care providers).; Geography: United States (NICHD campaign); Life stage: Newborn and infant, younger than 1 year; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (guidance and national counts) ### NICHD describes sudden infant death syndrome (SIDS) as the sudden death of a baby younger than 1 year of age that does not have a known cause, even after a full investigation. Sudden unexpected infant death (SUID) is the wider group: all sudden, unexpected infant deaths, whether from a known cause such as an injury or accident or from an unknown cause such as SIDS. About 3,000 SUIDs occur in the United States every year, and more than 1 in 3 of them are from SIDS. - Category: Burden - Evidence stage: Observational - Certainty: Certainty not assessed - Applies to: Recipient: Child; Population: Babies younger than 1 year of age and the people who care for them. The Safe to Sleep campaign addresses parents, grandparents, other relatives, babysitters, child care providers and anyone who might care for a baby. Counts on the page are for the United States.; Care setting: Home and child care sleep settings (the page lists parents, babysitters and child care providers).; Geography: United States (NICHD campaign); Life stage: Newborn and infant, younger than 1 year; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (guidance and national counts) - Limitations: The counts are from a NICHD page that cites a 2024 CDC data page, which the atlas did not read; the page does not say which year the counts refer to, and it gives rounded figures. The page does not give a rate per births. The definition of SIDS depends on an investigation, so a death that is later explained is not counted as SIDS. - Last checked: 2026-10-14 - Sources: 1. Supports: What is SIDS? (Safe to Sleep campaign) (Webpage, edition The page as shown on 2026-10-14. The page carries no edition date. Its United States counts are cited on the page to a 2024 CDC data page, which the atlas did not read.) Locator: What is SIDS?, paragraph 1. Retrieved 2026-10-14T18:21:31Z. Source state: Current. Snapshot hash: f6614c996b312a27d25c11479b0a82c1ed2e89191aa3739fc977a5a9118f8eca. How it applies: Definition of SIDS, part 1. 2. Supports: What is SIDS? (Safe to Sleep campaign) (Webpage, edition The page as shown on 2026-10-14. The page carries no edition date. Its United States counts are cited on the page to a 2024 CDC data page, which the atlas did not read.) Locator: Is it always SIDS?, paragraph 3. Retrieved 2026-10-14T18:21:31Z. Source state: Current. Snapshot hash: f6614c996b312a27d25c11479b0a82c1ed2e89191aa3739fc977a5a9118f8eca. How it applies: Definition of SUID. 3. Supports: What is SIDS? (Safe to Sleep campaign) (Webpage, edition The page as shown on 2026-10-14. The page carries no edition date. Its United States counts are cited on the page to a 2024 CDC data page, which the atlas did not read.) Locator: How common is SIDS?, sentence 1. Retrieved 2026-10-14T18:21:31Z. Source state: Current. Snapshot hash: f6614c996b312a27d25c11479b0a82c1ed2e89191aa3739fc977a5a9118f8eca. How it applies: Annual number of SUIDs in the United States. 4. Supports: What is SIDS? (Safe to Sleep campaign) (Webpage, edition The page as shown on 2026-10-14. The page carries no edition date. Its United States counts are cited on the page to a 2024 CDC data page, which the atlas did not read.) Locator: How common is SIDS?, sentence 2. Retrieved 2026-10-14T18:21:31Z. Source state: Current. Snapshot hash: f6614c996b312a27d25c11479b0a82c1ed2e89191aa3739fc977a5a9118f8eca. How it applies: Share of SUIDs that are SIDS. 5. Background: What is SIDS? (Safe to Sleep campaign) (Webpage, edition The page as shown on 2026-10-14. The page carries no edition date. Its United States counts are cited on the page to a 2024 CDC data page, which the atlas did not read.) Locator: Citations. Retrieved 2026-10-14T18:21:31Z. Source state: Current. Snapshot hash: f6614c996b312a27d25c11479b0a82c1ed2e89191aa3739fc977a5a9118f8eca. How it applies: Source the page cites for the counts. 6. Background: Sudden Infant Death Syndrome (MedlinePlus health topic) (Webpage, edition The health topic page as shown on 2026-10-14. The page carries no edition date. The summary is credited on the page to NIH: National Institute of Child Health and Human Development.) Locator: Summary, paragraph 1. Retrieved 2026-10-14T18:20:19Z. Source state: Current. Snapshot hash: f7b1a4baa716d01aa2ebe8877c5a3282f089ac2011ff10af63f40fa2ab43c145. How it applies: MedlinePlus definition of SIDS. ## Connected pages - Filed under this front: Care programmes and follow-up (`maternal:front-care-programmes-and-follow-up`) - MedlinePlus and NICHD list feeding human milk among steps that lower the risk of SIDS: Breastfeeding (`maternal:breastfeeding`) - Related to: Safe infant sleep (`maternal:safe-infant-sleep`) ## Provenance Content hash: bf182ff97fb668330ea2e44ca42c93835ebe4b835f792c83fa2296026a5c6fa3 Last substantive edit: 2026-10-14 Evidence last checked: 2026-10-14