A meta-analysis analyzing the impact of breastfeeding duration and the risk of Sudden Infant Death Syndrome (SIDS) will be published in the November issue of Pediatrics, concluding that breastfeeding for at least 2 months, regardless of exclusivity, is associated with a reduction in the risk of SIDS.

Source: Thompson JMD, et al. 2017. Duration of Breastfeeding and Risk of SIDS: An Individual Participant Data (IPD) Meta-analysis. Pediatrics. https://doi.org/10.1542/peds.2017-1324.

CONTEXT: Sudden infant death syndrome (SIDS) is a leading cause of postneonatal infant mortality. Our previous meta-analyses showed that any breastfeeding is protective against SIDS with exclusive breastfeeding conferring a stronger effect.The duration of breastfeeding required to confer a protective effect is unknown.

OBJECTIVE: To assess the associations between breastfeeding duration and SIDS.

DATA SOURCES: Individual-level data from 8 case-control studies.

STUDY SELECTION: Case-control SIDS studies with breastfeeding data.

DATA EXTRACTION: Breastfeeding variables, demographic factors, and other potential confounders were identified. Individual-study and pooled analyses were performed.

RESULTS: A total of 2267 SIDS cases and 6837 control infants were included. In multivariable pooled analysis, breastfeeding for <2 months was not protective (adjusted odds ratio [aOR]: 0.91, 95% confidence interval [CI]: 0.68–1.22). Any breastfeeding ≥2 months was protective, with greater protection seen with increased duration (2–4 months: aOR: 0.60, 95% CI: 0.44–0.82; 4–6 months: aOR: 0.40, 95% CI: 0.26–0.63; and >6 months: aOR: 0.36, 95% CI: 0.22–0.61). Although exclusive breastfeeding for <2 months was not protective (aOR: 0.82, 95% CI: 0.59–1.14), longer periods were protective (2–4 months: aOR: 0.61, 95% CI: 0.42–0.87; 4–6 months: aOR: 0.46, 95% CI: 0.29–0.74).

LIMITATIONS: The variables collected in each study varied slightly, limiting our ability to include all studies in the analysis and control for all confounders.

CONCLUSIONS: Breastfeeding duration of at least 2 months was associated with half the risk of SIDS. Breastfeeding does not need to be exclusive to confer this protection.