MONDAY, Jan. 26 (HealthDay News) -- Even while the rate of sudden infant death syndrome (SIDS) in the United States has declined, the rate of infant deaths from accidental suffocation in bed has quadrupled, a new study reports.
Such deaths have been most common among black boy babies younger than 4 months, according to the study, published in the February issue of Pediatrics.
The authors said the increase might be due to differences in classification rules and methods among medical examiners and coroners.
But, regardless, the message to parents and caregivers stays the same.
"The safest sleep environment for an infant is one that's close to the parent on a separate sleep surface," said study author Carrie K. Shapiro-Mendoza, an epidemiologist in the division of reproductive health at the U.S. Centers for Disease Control and Prevention. "Infants should always be placed to sleep on their back on a firm mattress, and the sleep surface should be free of pillows, quilts, comforters and stuffed animals."
Another issue related to infant deaths is co-sleeping, the term for when a baby sleeps with a parent, sibling or caregiver.
"The concern has as much to do with parental behavior," said Dr. Thomas G. DeWitt, director of the division of general and community pediatrics at Cincinnati Children's Hospital Medical Center. "If you're a deep, sound sleeper, or if you're on medication or if you're drinking, then it's really a bad idea to have the baby in the bed with you."
The United States ranks 29th in the world in infant mortality, according to data released in October for 2004. It ranked 27th in 2000, 23rd in 1990 and 12th in 1960.
Accidental strangulation or suffocation in bed is one of a number of conditions included under the umbrella term "sudden, unexpected infant deaths."
Such deaths can be caused by a baby sleeping on soft bedding such as a pillow or waterbed, a parent rolling on top of a baby while asleep, a baby getting stuck between a mattress and a wall or bed frame, or a baby catching his or her head between crib railings.
For their study, the authors examined data from death certificates for U.S. infants 1 year old and younger.
In the two decades from 1984 to 2004, infant death rates attributed to strangulation or suffocation in bed jumped fourfold, from 2.8 deaths per 100,000 live births to 12.5 deaths per 100,000 live births.
The biggest increase occurred between 1996 and 2004, when strangulation/suffocation deaths rose 14 percent. During this time, sudden, unexpected infant death rates overall remained relatively stable, with a possible trend downward after 2003, and deaths attributable to SIDS actually declined.
The decrease in SIDS has been attributed largely to the national "back to sleep" campaign, launched in 1999.
Strangulation or suffocation deaths, which occurred while the children were sleeping in beds, cribs or couches, were highest among black male babies younger than 4 months. Overall, black babies had a higher mortality rate from this type of death than did white babies (27.3 deaths per 100,000 births compared with 8.5 deaths per 100,000 births), and the rate was higher for boys than girls (12.5 vs. 9.6 deaths per 100,000 live births).
"That there's such a disparity between black versus white is important," DeWitt said. "The disproportion that we know happens in SIDS continues in this category as well."
Strangulation and suffocation deaths appear most common in infants 3 months old and younger, with most deaths occurring at 1 month of age. And they occur more often from Sunday through Wednesday than during the second half of the week.
"It seems that medical examiners or coroners seem to be moving away from SIDS as a diagnosis and more likely to report suffocation as the cause of death," said Shapiro-Mendoza. "We don't know the exact reason. It could have to do with better death investigation or stricter adherence to SIDS definition."
National death-scene guidelines for sudden, unexpected infant deaths were released in 1996, intended to standardize investigations and make them more user-friendly.
"One of the caveats here is: Was there truly an increase, or is there a more careful assessment of unexpected infant death cases?" Dewitt asked. "It's hard to know."
According to Dr. Cheryl Cipriani, an associate professor of pediatrics at Texas A&M Health Science Center College of Medicine and director of the Neonatal Intensive Care Unit at Scott & White hospital, as people have gotten better at identifying causes of death, some deaths that once were simply unexplained might now be attributed to accidental suffocation or strangulation rather than SIDS.
And, she said, the way SIDS has been defined has changed: If one component of the examination or investigation is missing, the death cannot be categorized definitively as "unexplained."
The authors of the study called for a more standardized nationwide system of investigating and classifying infant deaths in the United States as one means of furthering prevention efforts.
The American Academy of Pediatrics has more on infant safety.
SOURCES: Carrie K. Shapiro-Mendoza, Ph.D., epidemiologist, division of reproductive health, U.S. Centers for Disease Control and Prevention, Atlanta; Thomas G. DeWitt, M.D., director, division of general and community pediatrics, Cincinnati Children's Hospital Medical Center; Cheryl Cipriani, M.D., associate professor, pediatrics, Texas A&M Health Science Center College of Medicine, and director, Neonatal Intensive Care Unit, Scott & White, Temple, Texas; February 2009 Pediatrics