New estimates of maternal mortality and how to interpret them: choice or confusion?

Two independent exercises to estimate levels of maternal mortality took place during 2010, one published by the Institute for Health Metrics and Evaluation in Seattle, USA, the other published by four UN agencies (UNICEF, UNFPA, World Bank and World Health Organization). Although both approaches are based on similar sets of empirical country data, their statistical methods differ in important respects--with implications for the resulting global, regional and country estimates. This paper examines the differences, discusses both the value and inherent limitations in such exercises, proposes ways of interpreting the different estimates and suggests how such exercises could be made more relevant to the needs of country-level decision-makers. It calls on the global community to invest seriously in working with countries to generate primary data on maternal mortality using measurement methods that reduce uncertainty and generate data on a continuing basis. The best routine source of data on maternal deaths is a civil registration system that assures permanent, compulsory and universal recording of the occurrence and characteristics of vital events, including births and deaths, and causes of death. The record of deaths among women of reproductive age derived from civil registration is often the first step in conducting a confidential enquiry into and preventing maternal deaths.