Breast-Feeding Lowers Risk for Sudden Infant Death Syndrome

Laurie Barclay, MD

June 17, 2011

June 17, 2011 — Breast-feeding, particularly exclusive breast-feeding, is associated with a lower risk for sudden infant death syndrome (SIDS) according to the results of a meta-analysis reported online June 13 in Pediatrics.

"Benefits of breastfeeding include lower risk of postneonatal mortality," write Fern R. Hauck, MD, MS, from the Department of Family Medicine, University of Virginia School of Medicine in Charlottesville, and colleagues. "However, it is unclear whether breastfeeding specifically lowers ...SIDS risk, because study results have been conflicting."

The goal of this meta-analysis was to evaluate the relationship between breast-feeding and SIDS. A Medline search from 1966 to 2009, as well as a search of bibliographies of review articles and meta-analyses, identified 288 studies with data on breast-feeding and SIDS. Of 24 original case-control studies examining the association between breast-feeding and SIDS risk, 6 studies were excluded by 2 teams of 2 reviewers assessing study quality based on predetermined criteria.

Using the remaining 18 studies, the reviewers extracted univariable and multivariable odds ratios (ORs) and used the fixed-effect and random-effect inverse-variance methods of meta-analysis to calculate a summary odds ratio (SOR). Heterogeneity among studies was assessed with the Breslow-Day test.

The univariable SOR for SIDS was 0.40 (95% confidence interval [CI], 0.35 - 0.44) for receiving any amount of breast milk for any length of time, and the multivariable SOR was 0.55 (95% CI, 0.44 - 0.69). The univariable SOR was 0.38 (95% CI, 0.27 - 0.54) for any breast-feeding at age 2 months or older, and the univariable SOR for exclusive breast-feeding for any length of time was 0.27 (95% CI, 0.24 - 0.31).

"Breastfeeding is protective against SIDS, and this effect is stronger when breastfeeding is exclusive," the study authors write. "The recommendation to breastfeed infants should be included with other SIDS risk-reduction messages to both reduce the risk of SIDS and promote breastfeeding for its many other infant and maternal health benefits."

Limitations of this study include possible publication bias resulting in an overestimate of the true effect, which the reviewers thought was unlikely, and small number of studies that presented data on breast-feeding duration.

"The same benefits of breastfeeding in protecting against SIDS are found for black infants as for those in other groups," the study authors conclude. "However, breastfeeding initiation and continuation occur less frequently among black mothers and those of other racial/ethnic minorities and among socially disadvantaged mothers. In addition, these same groups have a higher incidence of SIDS. Thus, it is essential that breastfeeding interventions target these higher-risk populations, and future research should focus on developing and evaluating innovative intervention methods."

The study authors have disclosed no relevant financial relationships.

Pediatrics. Published online June 13, 2011. Full text


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