SIDS risk profile changed after Back-to-Sleep campaign
MedWire News: The risk profile for sudden infant death syndrome (SIDS) has significantly changed following the initiation of the US Back-to-Sleep (BTS) campaign, say researchers.
The National Institute of Child Health and Development aimed to reduce the prevalence of SIDS in the US with their BTS campaign in 1994, which advised caregivers to place infants on their backs to sleep. The campaign reflected major advances in SIDS research at the time, which showed that the prone (on the stomach) sleep position increases SIDS risk twofold.
After the BTS campaign was initiated, the SIDS rate initially declined dramatically, but has subsequently plateaued. Henry Krous (University of California, San Diego, USA) and colleagues therefore investigated whether the risk profile for the condition has changed since the BTS campaign was started.
They used data from the San Diego SIDS/Sudden Unexplained Death in Childhood Research Project, which recorded risk factors for 568 deaths between 1991 and 2008 based on standardized death scene investigations and autopsies.
The researchers divided risk factors into intrinsic and extrinsic factors. Intrinsic factors were defined as genetic/environmental factors affecting susceptibility, eg, African-American race, male gender, prematurity (<37 gestational weeks of birth), and prenatal maternal smoking or alcohol intake.
Extrinsic risk factors were defined as physical stressors around the time of death that may have increased the risk for SIDS in an already vulnerable infant. These included being placed or found in a prone/side sleep position, found face-down or with the head covered, sleeping on an adult mattress, couch, or playpen, soft bedding, bed-sharing, and signs of upper respiratory tract infection (URTI).
Between 1991-1993 and 1996-2008, the percentage of SIDS infants found prone decreased significantly from 84.0% to 48.5%. However, bed-sharing increased significantly from 19.2% to 37.9%, especially among infants aged less than 2 months.
In addition, the rate of prematurity increased significantly from 20.0% to 29.0%. Symptoms of URTI decreased significantly from 46.6% to 24.8%.
Of note, 99% of SIDS infants had at least one risk factor, 57% had at least two extrinsic and one intrinsic risk factors, and only 5% had no extrinsic risk factor.
The authors note that the average number of risk factors per SIDS infant had not changed significantly after the BTS campaign was initiated.
"Although SIDS is a disease, and these risk factors are not causative of SIDS in and of themselves, risk reduction campaigns that emphasize the importance of avoiding multiple and simultaneous SIDS risks are essential," write the authors.
"If caretakers are unable to meet all ideal sleep conditions, this study suggests that meeting as many as possible will still be beneficial," they conclude.
By Piriya Mahendra