Recognizing Risk Factors Could Prevent 95% of SIDS Cases
When thinking about the prevention of Sudden Infant Death Syndrome, or SIDS, most parents first think of the campaign “Back to Sleep” which promoted the placing of infants on their backs for naps or bedtime instead of on their stomachs or sides. And for good reason: the simple act has reduced the amount of SIDS deaths by more than 50%. However, parents should still be aware of other factors that can increase the risk of SIDS and potentially, 95% of cases could be prevented.
The Back to Sleep campaign was first initiated by the National Institute of Child Health and Development in 1994. Although the effort has been extremely successful, there are still about 2,500 SIDS deaths per year and remains the leading cause of post-neonatal infant mortality in the United States. Therefore, it is extremely important to identify and prevent the “precise risk factors for SIDS,” writes Felicia L. Trachtenberg PhD from the New England Research Institutes in Watertown, Massachusetts.
Sudden Infant Death Syndrome is defined as the sudden, unexpected death of an infant younger than 1 year that occurred during sleep and remains unexplained after a thorough investigation including autopsy. About 90% of SIDS cases occur between the second and sixth months of life.
Dr. Trachtenberg reviewed data on infant deaths from the San Diego Medical Examiner’s Office collected between 1991 and 2008. Sixty percent (568 cases) were due to SIDS. Risk factors were divided into two categories: intrinsic (belonging to the essential nature of a thing) which includes race, gender, birth condition and prenatal exposures, and extrinsic (coming from outside) such as sleep conditions and the presence of an infection.
Overall, 99% of the cases had at least one intrinsic or extrinsic factor; most had at least one of each type. Only 5% had no identifiable outside cause of death. The authors emphasize that in most cases, a combination of risks increase the odds of SIDS.
Sleeping on the stomach, or “tummy sleeping”, remains the leading risk factor for SIDS, says study co-author Dr. Henry Krous, the director of the San Diego SIDS/Sudden Unexplained Death in Childhood Research Project.
Bed-sharing where the baby shares a sleeping surface with a parent or parents is a major risk as well. Bed-sharing has increased from 19% to almost 38% during the study period. “Co-Sleeping” or “Family Bed”-type arrangements have increased in popularity because parents feel babies sleep more easily or they prefer an arrangement that promotes nighttime breastfeeding.
According to the Consumer Product Safety Commission (CPSC) at least 515 deaths of infants and toddlers under two were linked to sharing an adult bed during the 1990s. Many were attributed to a parent, caregiver, or sibling rolling on top of or against a baby while sleeping.
Another sleeping situation placing babies at increased risk is the use of soft bedding (ie: bumper pads, pillows) or objects such as stuffed animals in the crib. Also watch for blankets that creep upward and cover the infant’s head. The room or sleeping environment should not be excessively warm.
Cigarette smoke exposure also puts the infant at considerable risk. Prenatal smoke exposure contributes to neonatal breathing problems due to hypoxia (low oxygen). Nicotine is also known to have an effect on embryonic development and postnatal growth – other factors involved in SIDS. Even in moms who do not smoke while pregnant, their exposure to second-hand smoke increases the risk for the unborn child.
Of course, cigarette exposure after birth is detrimental to the infant’s health as well. “There is no risk-free level of exposure to secondhand smoke,” says the American Academy of Pediatrics.
Some SIDS risk factors are unavoidable, but parents should still remain aware that they make an infant more susceptible. These include being male, black, premature, or having symptoms of an Upper Respiratory Tract Infection (URTI).
"Even if you can't achieve a perfect sleep environment for your baby, getting rid of some of the risk factors goes a long way," Trachtenberg said.
The American Academy of Pediatrics offers a parent's guide to safe sleep.
Risk Factor Changes for Sudden Infant Death Syndrome After Initiation of Back-to-Sleep Campaign
Felicia L. Trachtenberg, Elisabeth A. Haas, Hannah C. Kinney, Christina Stanley, and Henry F. Krous
Pediatrics peds.2011-1419; published ahead of print March 26, 2012, doi:10.1542/peds.2011-1419