Although a national campaign emphasizing the importance of safe sleeping practices for babies is credited with slashing the rate of sudden infant death syndrome (SIDS) and reducing infant death from other sleep-related causes, new studies pinpoint areas where additional work is needed.
According to research being presented today at the Pediatric Academic Societies meeting in Vancouver, 19% of mothers report that they usually share a bed with their baby, an increasingly common practice that's been shown to make infants nearly three times more likely to die from SIDS than infants who sleep alone.
The bed-sharing rate was highest among Hispanic mothers (28%), compared with black (18%) and white mothers (14%), according to the research led by pediatrics professor Eve Colson of Yale University School of Medicine.
"Bed sharing is definitely on the rise," say Colson, who analyzed a nationally representative sample of 1,031 mothers recruited from 32 hospitals across the country for this new study.
Research she published last year using surveys of 19,000 caregivers in 48 states found that from 1993 to 2010 the incidence of baby bed-sharing or co-sleeping more than doubled from 6.5% to 13.5%.
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Based on the new data analysis, the overall rate for usually putting an infant to sleep in the prone or stomach-down position, also considered a high-risk practice, was just 9%, on target with national reduction goals, Colson says. However, the practice was reported by 20% of black mothers, compared with 10% of white and 6% of Hispanic mothers.
According to the Centers for Disease Control and Prevention, the government's Back to Sleep education campaign, first introduced in 1994, has reduced the rate of SIDS by 50%, but that decline stalled as rates of other sleep-related causes of infant death, such as accidental suffocation, have increased.
In 2012, the campaign was renamed Safe to Sleep and expanded to encompass all sleep-related, sudden unexpected infant deaths (SUID) as well as highlight theAmerican Academy of Pediatrics' recommendations for reducing them.
In addition to always putting babies on their backs to sleep and eliminating bed-sharing, the AAP recommendations include avoiding bumpers and soft, loose bedding, not letting babies overheat, and keeping them away from smokers and places where people smoke.
SIDS is the leading cause of death among infants between 1 month and 1 year of age, according to the CDC. In 2010, the most recent year that statistics were available, 2,063 deaths were reported as SIDS; 918 as cause unknown; and 629 as accidental suffocation and strangulation in bed.
It's not clear what causes SIDS, nor is there an absolute understanding of how back-sleeping protects infants, says Colson, although some ideas include "that it offers better exposure to fresh air, and the system that allows you to wake up when you're (having breathing difficulties) is better activated when you're on your back."
Another new study to be presented at the PAS conference shows that back-sleeping for infants varies widely by state and is particularly low among preterm babies two to four months after discharge from the hospital.
"The more preterm the babies were, the less likely they were to be placed on their back," says study leader Sunah Hwang, a neonatologist at Boston Children's Hospital and South Shore Hospital.
"That's particularly worrisome given that these are more vulnerable infants who are at higher risk for SIDS, sleep-related deaths and other complications," Hwang says.
Only 60% of the earliest preterm infants (born 27 weeks or less) were usually positioned on their back for sleep by parents, compared with 62% of infants born 28-33 weeks, 63% of late-preterm infants (born 34-35 weeks) and 68% of full-term infants (born at 37 to 42 weeks).
The analysis, based on data collected from new mothers of 392,397 infants born in 36 states between 2000 and 2011 also found that Louisiana had the lowest back-sleeping rate (47%) for all infants (preterm and full-term), followed by Alabama and Mississippi (49% each). Wisconsin had the highest rate (81%), followed by Wyoming and Minnesota (79% each).
In 2011, the overall back-sleeping rate was 70%, says Hwang, adding that "even in the worse performing states there has been improvement."
New parents get a ton of advice from well-meaning family and friends that can affect how they put their babies to sleep, along with media ads that may show babies in attractive but unsafe sleep environments, says Linda Fu, a pediatrician at Children's National Medical Center, in Washington, D.C. She was not involved in the new study.
At the same time, parents have to make decisions about how they will best handle exhausting middle-of-the-night wake-up calls, Fu says. But "for certain things where there's such a preponderance of evidence there's no leeway," she says. "The safest position and place for infants when sleeping is on their back and in a separate crib or bassinet next to their parents, not in the bed with them."