The rate of accidental suffocation deaths among babies increased fourfold over the past two decades, according to a new study, despite a national campaign to encourage safe infant sleeping.
Authors of the study, which appears today in the journal Pediatrics, say the nationwide increase probably is the result of more thorough investigations and changes in how deaths are classified. Nevertheless, the researchers and local medical experts said the figures reflect a continuing problem and highlight concerns about whether babies should sleep in the same beds as their parents or siblings.
"These deaths are likely preventable," said Carrie K. Shapiro-Mendoza, an epidemiologist at the federal Centers for Disease Control and Prevention and lead author of the study. "So this problem is ongoing, and we should not divert our attention. ... We need an infusion of more efforts to make them reduce further."
Researchers have long studied Sudden Infant Death Syndrome, a term that refers to infant deaths that cannot be explained after a medical investigation. Shapiro-Mendoza's study sought to find out if a newer, more specific category of infant death - by strangulation or suffocation - was increasing.
The National Institutes of Health launched a Back to Sleep campaign 13 years ago to reduce infant deaths, encouraging parents to place babies on their backs. Since then, deaths attributed to SIDS have decreased 50 percent, and pediatricians and child safety advocates cheered the campaign's success.
But taking a closer look at death certificates nationwide, Shapiro-Mendoza and others noticed a rise in infant deaths classified as suffocation or strangulation. These included babies becoming wedged between a wall and a mattress, another person rolling on top of an infant or suffocation on a pillow or soft mattress.
Dr. Scott D. Krugman, co-chairman of the Baltimore County Child Fatality Review Team, which reviews such deaths, said the study sends a clear signal that the Back to Sleep campaign is not enough.
"When the SIDS rates started plummeting, we all said to ourselves, 'Look, we're making such progress,' " said Krugman, who is chairman of pediatrics at Franklin Square Hospital Center. "But we were not looking at the fact that the total number of deaths has stayed the same. Sleep safety is the issue; we're just calling the deaths something else."
Researchers found that from 1984 to 2004, infant suffocation and strangulation deaths nationally rose from 2.8 per 100,000 live births to 12.5 per 100,000 live births. The largest increase took place after 1996, about the same time that SIDS rates leveled off.
Dr. Charles Shubin, director of pediatrics at Mercy Medical Center in Baltimore, said he thinks investigators have become more "honest" about classifying infant deaths. SIDS was often the catch-all for unexplained infant deaths, but closer investigation revealed that babies were suffocating accidentally.
The issue is serious in Baltimore, where the review team found 89 unexpected infant deaths between 2002 and 2006 and said that unsafe sleeping environments contributed to 91 percent of them.
"A decade ago, there were no real investigations," said Shubin, who helped organize Baltimore's child fatality review team to push for greater investigation of such deaths. "As we began to look at other ways that might be surrounding circumstances, the definition of SIDS became harder to meet, so we came up with a new diagnosis."
"This doesn't represent more children dying of asphyxia, it means we are recognizing it more accurately," Dr. David Fowler, Maryland's chief medical examiner, said of the new study. "Medical technology has improved. Training of death investigators and examiners has improved."
Even so, medical examiners differ widely in how they diagnose sudden infant deaths, Shapiro-Mendoza said.
"Some states might have a board-certified pediatric pathologist; other states may have a coroner who is an elected official and may have a [high school equivalency certificate] for their education," she said.
She said experts need uniform standards to analyze infant deaths and develop strategies to avoid them. The CDC wants to compile a database of infant deaths nationwide, with medical examiner and law enforcement reports and infant medical records.
For now, doctors such as Shubin and Krugman advise parents not to place a baby on soft bedding, to keep toys and pillows away from a baby's sleep area, and to adopt the ABC approach (Alone, on their Back and in a Crib). But not everyone agrees.
While the American Academy of Pediatrics discourages parents from sleeping with their infants, groups such as La Leche League and those that advocate "attachment parenting" say that babies can sleep with their parents safely and that the practice encourages lasting bonds.
And cultural and economic barriers sometimes prevent parents from using cribs or inventions considered safe, such as bassinets that attach to a bed.
Low-income parents might not be able to afford a crib, and immigrants, particularly from Asia or Latin America where sharing a bed is common, are reluctant to abandon doing so, Krugman said.
"I tell them, 'Your child is safest in a safe environment,' " he said. " 'I want you to bond with your child, but I want them to be safe.' "