June 13, 2011 -- Protection against sudden infant death syndrome (SIDS) may be yet another benefit of breastfeeding.
A new review of recent research studies shows that infants who were breastfed were about 60% less likely to die from SIDS than infants who didn't receive any breast milk. This protective effect increased the longer the baby was breastfed and if the baby was exclusively breastfed.
“Breastfeeding to any extent and of any duration is protective against SIDS,” researcher Fern Hauck, MD, of the department of family medicine at the University of Virginia in Charlottesville, and colleagues write in Pediatrics.
Researchers say there are many proven physical and emotional benefits of breastfeeding, but it has been unclear whether breastfeeding specifically lowers the risk of SIDS. Some studies have suggested a protective effect of breastfeeding against SIDS, while others have not.
But they say many of these studies included broader definitions of SIDS and methodological flaws that may have affected results.
In this study, researchers identified 288 studies on SIDS and breastfeeding from 1966 to 2009 and narrowed their analysis to 18 studies that met basic research quality criteria.
The results showed that for infants who received any breastmilk for any duration, the likelihood of SIDS was 60% lower. For infants who were breastfed at 2 months of age and older, the risk was 62% lower.
Exclusive breastfeeding without any use of formula for any duration appeared to provide the biggest benefits. The risk of SIDS among exclusively breastfed infants was 73% lower.
Although these findings are based on observational studies and cannot prove a direct cause and effect relationship between breastfeeding and SIDS prevention, researchers say there are several plausible biological reasons.
For example, breastfed infants may be more easily aroused from sleep than formula-fed infants at 2-3 months of age, which is within the 2-4 months peak age of SIDS cases.
In addition, breastfeeding delivers antibodies known as immunoglobulins that may help protect infants from infection during the period they are most at risk for SIDS.
Researchers say the results suggest that the recommendation to breastfeed infants should be included with other SIDS risk-reduction information given to pregnant women.