The Impact of Anemia on Maternal Mortality: An Updated Review

Maternal mortality is a significant global problem; in developing countries, death surrounding pregnancy affects half a million women annually. Anemia affects a quarter of the world's population and contributes to maternal mortality. This review provides updated estimates of the effect of anemia on maternal mortality globally. A systematic literature review in Pubmed, Scopus, EMBASE, and Web of Science was conducted to find relevant studies published since 2001 (updating Stoltzfus et al. 2004). Four articles that met inclusion criteria and presented sufficient data for analysis, combined with six original studies from Stoltzfus et al. (2004), were used to produce new estimates for maternal mortality. For each study, a logistic regression of maternal mortality on midpoint of hemoglobin (Hb) range was run, and combined effect sizes were estimated with the DerSimonian & Laird (DSL) (1986) method and a mixed model with random effects. The odds ratios for maternal mortality were 0.75 (95% CI, 0.65–0.87) and 0.72 (95% CI, 0.61–0.86) for each 1 g/dL increase in maternal Hb level using the DSL and the mixed model methods, respectively. These results indicate that even a relatively small change in hemoglobin (1 g/dL) at the end of pregnancy can greatly reduce maternal mortality risk by 25%. Such results could have substantial policy implications for preventing maternal mortality through anemia interventions. Grant Funding Source : Bill and Melinda Gates Foundation through a grant to the US Fund for UNICEF to support the Child Health Epidemiology Reference Group