Definitions: SUID, SIDS, SUDC, Fetal Death, Infant Mortality, Stillbirth, & Miscarriage
Table of Contents
Sudden infant death syndrome (SIDS) is the sudden death of an infant under age 1 that cannot be explained after a thorough investigation has been conducted, including a complete autopsy, an examination of the death scene, and a review of the clinical history.
See Centers for Disease Control and Prevention (CDC), Sudden Infant Death Syndrome (SIDS) and Sudden Unexpected Infant Death (SUID): Home for expanded information on terminology.
SUID is the sudden and unexpected death of an infant in which the manner and cause of death are not immediately obvious prior to investigation.
How are SUID and SIDS different? SUID can be caused by metabolic disorders, hypothermia or hyperthermia, neglect or homicide, poisoning, or accidental suffocation. Some SUIDs are attributed to SIDS. Sometimes the cause is unknown. In 2004, about 4,600 U.S. infants died suddenly of no immediately obvious cause, and nearly half of these SUID deaths were attributed to SIDS.
The SIDS rate has been declining significantly since the early 1990s. However, CDC research has found that the decline in SIDS since 1999 corresponds to an increase in SUID rates (e.g., deaths attributed to overlaying, suffocation, and wedging) during the same period.
This change in the classification of SUID can be explained by changes in how investigations are conducted and how SUID is diagnosed. (Centers for Disease Control and Prevention, Sudden Unexpected Infant Death (SUID) Initiative.)
Used with permission from Centers for Disease Control and Prevention
What is sudden unexplained death in childhood (SUDC)?
SUDC is the sudden and unexpected death of a child over the age of twelve months, which remains unexplained after a thorough case investigation is conducted. This must include: examination of the death scene, performance of a complete autopsy, and a review of the child and family’s medical history. SUDC is a diagnosis of exclusion - given when all known and possible causes of death have been ruled out. (The CJ Foundation for SIDS and the SUDC Program)What is fetal death?
Fetal death is defined as the loss of a fetus at any time during pregnancy, not including induced abortions. (Emedicine, WebMD).
Also see the American Academy of Pediatrics' Standard Terminology for Fetal, Infant, and Perinatal Deaths (2011) which discusses terminology and reporting requirements.
Both “miscarriage” (also known as spontaneous abortion) and “stillbirth” are terms describing fetal death, but they refer to losses that occur at different times during pregnancy.
Although there is no universally accepted definition of when a fetal death is called a stillbirth vs. a miscarriage, in the United States “stillbirth” refers to a fetal death that occurs after 20 weeks of completed gestation, and “miscarriage” usually refers to a fetal death that occurs at 20 weeks of completed gestation or earlier.
Stillbirth is more common than many people realize. Each year, about 25,000 infants are stillborn in the United States— almost 10 times the number of deaths that occur from SIDS.
Because of tremendous advances in medical technology over the last 30 years, prenatal care has improved, and the occurrence of late and term stillbirths has dropped dramatically. However, the rate of early stillbirth (fetal death occurring between 20 and 27 weeks of completed gestation) has remained essentially unchanged.
Common causes of fetal death include problems with the infant (birth defects or genetic abnormalities), problems with the placenta or umbilical cord, and certain conditions in the mother (e.g., uncontrolled diabetes, hypertension). (First Candle)
Overview of stillbirth
March of Dimes. Stillbirth. Quick reference: Fact sheet.
Overview of miscarriage
March of Dimes. Miscarriage. Quick reference: Fact sheet.
Mayo Clinic. Miscarriage.
A comprehensive, multidisciplinary review of child deaths, to better understand how and why children die, and use the findings to take action that can prevent other deaths and improve the health and safety of children. For more information see the National Center for the Review and Prevention of Child Deaths, which is a technical assistance program of the Michigan Public Health Institute partly funded by the Maternal and Child Health Bureau.
- Fetal mortality
The number of fetal deaths. Although the vast majority of fetal deaths occur early in pregnancy, most states in the United States report only fetal deaths occurring at 20 weeks or more of completed gestation. CDC notes that this definition of fetal death avoids the confusion arising from the use of terms such as “stillbirth” and “miscarriage.” Centers for Disease Control and Prevention. 2009. Fetal and perinatal mortality, United States, 2005. National Vital Statistics Reports 57(8).
- Infant mortality
The number of deaths among liveborn infants from birth to under age 1.
- Fetal and infant mortality review A process that brings together key members of the community to review information from individual cases of fetal and infant death in order to identify factors associated with those deaths, establish if they represent system problems that require change, develop recommendations for change, assist in the implementation of change, and determine community effects. National Fetal and Infant Mortality Review Program. 2008. Fetal and infant mortality review manual: A guide for communities. 2nd edition. For more information see the National Fetal and Infant Mortality Review Program (NFIMR), which is a national technical assistance organization for Fetal and Infant Mortality Review (FIMR) programs. It is a collaborative effort between the American College of Obstetricians and Gynecologists (ACOG) and the federal Maternal and Child Health Bureau (MCHB).
- Neonatal mortality
The number of deaths from birth to under age 28 days.
There are two definitions of perinatal mortality:
- The number of deaths of infants under age 7 days, plus fetal deaths that occur at 28 weeks or more of completed gestation. (This definition is preferred for international comparisons.)
- The number of deaths of infants under age 28 days, plus fetal deaths that occur at 20 weeks or more of completed gestation. (This more inclusive definition is generally used in the United States).
The number of deaths from age 28 days to under age 1. Centers for Disease Control and Prevention. 2008. Infant mortality statistics from the 2005 period linked birth/infant death data set. National Vital Statistics Reports 57(2).