How Risk Factors for SIDS Have Changed Since the Back-to-Sleep Campaign

A higher percentage of cases are now associated with side sleep position and bed-sharing, and prone position still accounts for 30% of cases.

Although the rate of sudden infant death syndrome (SIDS) in the U.S. has declined more than 50% since the start of the 1994 Back-to-Sleep campaign, the rate has plateaued and SIDS remains the leading cause of postnatal infant mortality. To determine residual risk factors for SIDS, researchers conducted detailed case studies of 568 SIDS deaths from 1991 to 2008 in San Diego County, California. Risks were considered either intrinsic (gestational age at birth <37 weeks, black race, prenatal exposure to alcohol or cigarette smoking) or extrinsic (prone or side sleep position, bed-sharing, overbundling, covered head, upper respiratory tract infection).

The SIDS rate in the county declined from 1.34 per 1000 births in 1991 to 0.64 per 1000 births in 2008. The percentage of cases found in the prone position declined from 84% to 49%, the percentage found in the side sleep position increased from 7% to 17%, and the percentage of infants bed-sharing at the time of death increased from 19% to 38% (especially among infants younger than 2 months). Although most SIDS cases continue to occur in infants aged 2 to 4 months, the percentage of infants younger than 2 months and older than 4 months increased slightly, as did the percentage of premature infants. The percentage of cases associated with upper respiratory tract infections decreased from 47% to 25%. At least one risk factor was identified in 99% of cases; most (57%) had at least two extrinsic and one intrinsic risk factor. Only 5% of cases did not have an identified intrinsic risk factor.

Comment

Thirty percent of infants with sudden infant death syndrome still are found in the prone position, and the percentage of infants placed or found in the side sleep position accounts for an increasing proportion of cases. The side sleep position is not a safe alternative: The authors report that nearly half of SIDS infants placed on their side for sleep are found prone at the time of death. Bed-sharing is also an important risk factor, particularly in children younger than 2 months.

Reviewing Author

F. Bruder Stapleton, MD

Disclosures

Consultant/Advisory BoardCareer Physician

Editorial BoardsUpToDate

Leadership Positions in Professional SocietiesAmerican Society of Pediatric Nephrology Foundation (Chair)

F. Bruder Stapleton, MD

Disclosures

Consultant/Advisory BoardCareer Physician

Editorial BoardsUpToDate

Leadership Positions in Professional SocietiesAmerican Society of Pediatric Nephrology Foundation (Chair)

Citation(s):

Trachtenberg FL et al. Risk factor changes for sudden infant death syndrome after initiation of Back-to-Sleep campaign. Pediatrics 2012 Mar 26; [e-pub ahead of print]. (http://dx.doi.org/10.1542/peds.2011-1419)