What is SIDS? SIDS is the sudden death of an infant under one year of age that remains unexplained after of a complete post-mortem investigation, including an autopsy, an examination of the scene of death, and a review of the case history.
How often does SIDS occur? SIDS is the leading cause of death in infants between one month and one year of age. In the United States, it occurs in approximately 1 in 1,000 babies. In the past few years, around 3,000 babies die from SIDS each year in the United States.
When is SIDS most likely to occur? Ninety percent of SIDS occurs by six months of age, with most cases occurring between two and four months of age. SIDS occurs during an infant’s sleep, either nighttime or naptime and occurs most frequently between 10 p.m. and 10 a.m., with the peak time of death around 5 a.m. SIDS is more common during the winter months. For unknown reasons, SIDS is higher in males than females by a ratio of 1.5 to 1.0.
Are some babies more at risk for SIDS than others? Yes. While most babies dying of SIDS have no previous warning signs or apparent risk factors, some infants are at higher risk than others. The term “risk factor” refers to some element in the baby’s environment or development that increases the chances of dying of SIDS. Remember, “risk factor” is a clue, something associated with SIDS, not a cause. It means only that there is a statistical increase in SIDS among the overall population of babies who have that factor. The main risk factors for SIDS are:
- Smoking or taking illegal drugs during pregnancy
- Smoking around baby after birth
- Putting baby to sleep on their stomach
- Infants who are not breastfeeding
- Having little or no prenatal care
- Unsafe sleeping environment
- There is no correlation between immunizations and SIDS.
SIDS researchers have taken the above risk factors and translated this information into suggestions for reducing the risk of SIDS. These risk factors are a clue, but not a cure to the mystery of SIDS.