For more than 50 years, researchers have studied the numerous diagnoses related to unexplained infant deaths. They have been predominantly related to sleep. This vast body of work led to the identification of sudden infant death syndrome (SIDS) that was eventually limited to infants under 1 year of life (Goldstein, 2020). Understanding of SIDS as a sleep-related disorder led to development of the Back to Sleep Campaign in 1994 by the National Institute of Child Health and Human Development (NICHD) in partnership with the American Academy of Pediatrics, and the Maternal and Child Health Bureaus of the Health Resources and Services Administration. Now known as the Safe to Sleep Campaign, these campaigns have educated thousands of healthcare professionals, child care providers, and parents and have significantly expanded our scientific understanding of SIDS. As a result, SIDS rates in the United States have decreased by almost 50%, both overall and within various racial and ethnic groups. However, SIDS remains the leading cause of death for U.S. infants 1 month to 1 year of age (NICHD, 2020).
Early in 2020, for the first time, researchers determined there are significant subcategories of sudden unexplained infant death (SUID) that are based on age of infant at death. They analyzed data from >41 million births from 2003 to 2013 that included 37,624 cases of SUID. Sudden infant death syndrome is defined by the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics as “a term that combines three cause of death categories of infants < 1 year of age in the International Classification of Diseases, 10th Revision (ICD-10: sudden infant death syndrome (SIDS; R95), deaths from other ill-defined or unknown causes (R99), and accidental suffocation and strangulation in bed (W75)” (Lavista Ferres, Anderson, Johnston, Ramirez, & Mitchell, 2020, p. 2).
Two subcategories were identified: sudden unexpected postnatal collapse (SUPC) and sudden unexpected early neonatal deaths (SUENDs). Deaths in both subcategories occur early in life (<7 days) but do not have separate ICD-10 diagnostic codes. The authors argue that significant differences between these two warrant separate codes, based on their retrospective cross-sectional study conducted between 2003 and 2013 using CDC data of 37,624 SUID cases. Using logistic regression modeling, they compared deaths from these two categories with the following variables: maternal education, race, marital status, and smoking; paternal race; sex of infant; live birth order; prenatal care visits; birthweight; birth method; and gestation.
Results showed deaths that occurred in the first week (0-6 days; (SUEND) were significantly different from all other SUIDs (7-364 days) and could distinguish between the two populations with 77% accuracy. Findings included:
- The first day of life is correlated with the largest risk of death for SUID cases;
- A second peak for death occurs over 1 to 4 months;
- Risk factors for SUEND include: lower birth order (first live birth), parents being married, and low birthweight;
- Risk factors for postnatal SUID include higher birth order (≥ second live birth), young single mothers, and maternal smoking during pregnancy.
This important groundbreaking research will assist in enhancing epidemiological explanations of these two subcategories of SUID. Although future research is needed to compare and contrast additional behavioral variables with time of death, previous research has clearly linked the prone position to SUID. Nurses must continue to advocate for and educate parents on the principles of the Safe to Sleep Campaign.
Goldstein R. D. (2020). Sudden unexplained infant deaths and day of life. Pediatrics
, 145(1), e20193212. https://doi.org/10.1542/peds.2019-3212
Lavista Ferres J. M., Anderson T. M., Johnston R., Ramirez J. M., Mitchell E. A. (2020). Distinct populations of sudden unexpected infant death based on age. Pediatrics
, 145(1), e20191637. https://doi.org/10.1542/peds.2019-1637
National Institute of Child Health and Human Development. (2020). Progress in reducing SIDS
[Website]. Retrieved from https://safetosleep.nichd.nih.gov/activities/SIDS/progress