Jan. 26, 2009 -- Rates of infant mortality due to accidental suffocation and strangulation in bed have quadrupled since 1984, a new study shows.
The seeming contradictions in increases and declines in deaths of infants are likely due to changes in the way such tragedies are investigated and classified, researcher Carrie K. Shapiro-Mendoza, PhD, of the CDC, tells WebMD.
The reason for the sharp increase in accidental suffocation and strangulation in bed, or ASSB, isn't known for sure.
"It's probably due to poor bedding, blankets in cribs, sleeping with parents or siblings, or bad habits," she tells WebMD. "Or infants getting wedged between the mattress and the wall."
Also, despite urgings from the American Academy of Pediatrics and the CDC, many parents still put babies to bed on their stomachs, which can lead to suffocation.
The decline in SIDS rates has been offset by an increase in other sudden unexplained infant deaths, a new category called SUIDs. ASSB death, a subgroup of SUIDs, is a leading cause of infant mortality, says Shapiro-Mendoza.
SUIDs include all deaths attributed to accidental suffocation and strangulation, SIDS, and unknown causes.
Shapiro-Mendoza tells WebMD that infant deaths attributed to ASSB increased from 2.8 to 12.5 deaths per 100,000 live births between 1984 and 2004. She says such deaths increased dramatically between 1996 and 2004 (14% average yearly increase), a period in which mortality attributed to SIDS declined.
Black males under 4 months were disproportionately affected by accidental suffocation and strangulation, Shapiro-Mendoza says.
Preventing Infant Deaths
Shapiro-Mendoza tells WebMD that ASSB deaths are potentially preventable. She says a "comprehensive" investigation of the site of death is critical in determining cause of death. Often, she says, autopsy findings can't tell the difference between strangulation or physiological causes such as heart defects.
All mysterious infant deaths used to be classified as SIDS cases, she says, adding that coroners and medical examiners need to be more careful about diagnosing cause of death to help scientists fight infant mortality.
"A death scene investigation, an autopsy, and a review of medical records are essential to correctly classify these deaths," she tells WebMD.
It's unlikely that comprehensive investigations are the rule, she adds.
New parents also often get conflicting advice, she says.
"A lot of grandparents still say, put the baby on its stomach," Shapiro-Mendoza says. "That's bad advice."
Seema Csukas, MD, director of child health promotion at Children's Healthcare of Atlanta, says the medical community has "gotten better at defining what is SIDS and what isn't SIDS. Some of these may be genetic, caused by heart problems. The strangulation-suffocation deaths shouldn't be increasing."
Bradley Thach, MD, of the Washington University School of Medicine, tells WebMD that coroners and others are beginning to understand that many SIDS cases should be classified as suffocations.
"Sudden unexpected infant death is broader, including true SIDS as well as cases of accidental suffocation," he says. "We now know there are several causes of sudden death and some can be found only in post-mortem tests."
It's also becoming more recognized, he says, "that if you put babies face down they are more likely to suffocate."
Reducing Infant Deaths: Tips for Parents
Csukas says parents and all caregivers should be familiar with American Academy of Pediatrics and CDC guidelines, which if followed will reduce infant mortality.
Here are some recommendations from Csukas and Thach:
- Don't sleep with infants or allow others to.
- Make sure that infants are put to bed on their backs, not their stomachs.
- Infants should sleep on hard mattresses. Soft "squishy" bedding can lead to suffocation.
- Remove heavy blankets or stuffed toys from sleep area.
- Consider using single-piece sleep attire, sometimes called "sleepers," that would keep the infant warm without blankets or coverings.
- Clear cribs. Infants have strangled on cords from Venetian blinds.
- Slats on cribs should not be far enough apart for an infant's head to stick through.
- Use thin bumper pads, not thick ones.
- Ask your doctor for advice, not necessarily mothers or grandmothers. Times have changed, and so has advice.
- Be aware that cribs bought at garage sales or found in attics might not meet current guidelines of the Consumer Product Safety Commission.
- Putting infants to sleep on their sides is dangerous; it's easy for them to roll onto their stomachs.
- Do not smoke around infants.
- Make sure caregivers know what you do about putting your infant or baby to sleep. Many don't, even at established day-care centers.
- Pacifiers may be used when placing an infant down to sleep, but they should not be reinserted after he or she goes to sleep.