Background: Breastfeeding promotion and support are not universally accepted in the United States as a strategy to reduce infant mortality. We investigated associations between breastfeeding and infant mortality in an urban population with high infant mortality and low breastfeeding rates. Methods: A retrospective epidemiologic study linked birth-infant death data for 148,679 live births in Shelby County, Tennessee from January 2004 to December 2014. Births <500 g, deaths ≤7 days, deaths because of congenital anomalies or malignant neoplasms, and records with missing breastfeeding status were excluded. Main outcomes were infant death before the first birthday, neonatal death <28 days, and postneonatal death ≥28 days by ever or never breastfed. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for breastfeeding initiation were adjusted for maternal factors and infant factors. Results: Initiation of breastfeeding was associated with a significant reduction in total infant mortality (OR = 0.81, 95% CI = 0.68-0.97, p = 0.023). Neonatal mortality was also significantly reduced with any breastfeeding (OR = 0.49, 95% CI = 0.34-0.72, p = 0.001). Postneonatal mortality was not significantly associated with breastfeeding initiation in the overall population (OR = 0.95, 95% CI = 0.78-1.17, p = 0.65), but was significant in the nonblack population (OR = 0.63, 95% CI = 0.41-0.98, p = 0.039). An association was observed between breastfeeding initiation and infant mortality from infectious disease (OR = 0.49, 95% CI = 0.32-0.77, p = 0.002). Conclusions: In an urban area with high infant mortality and low breastfeeding rates, initiation of breastfeeding was significantly associated with reductions in overall infant mortality, neonatal mortality, and infection-related deaths. Breastfeeding promotion, protection, and support should be an integral strategy of infant mortality reduction initiatives.
Keywords: breastfeeding; disparities; infant mortality.