Maternal mortality ratio (per 100 000 live births)
Rationale for use
Complications during pregnancy and childbirth are a leading cause of death and disability among women of reproductive age in developing countries. The maternal mortality ratio represents the risk associated with each pregnancy, i.e. the obstetric risk. It is also a Millennium Development Goal Indicator for monitoring Goal 5, improving maternal health.
Definition
Number of maternal deaths per 100 000 live births during a specified time period, usually 1 year.
Associated terms
Maternal death is the death of a woman while pregnant or within 42 days after termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes. To facilitate the identification of maternal deaths in circumstances in which cause-of-death attribution is inadequate, ICD 10 introduced an additional category, pregnancy-related death, which is defined as the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the cause of death.
Live birth
Data sources
Vital registration, household surveys, census, health service records and specific studies on reproductive-age mortality (RAMOS).
Methods of estimation
Measuring maternal mortality accurately is difficult except where comprehensive registration of deaths and their causes exist. Elsewhere, censuses or surveys can be used to measure levels of maternal mortality. Data derived from health-services records are problematic where not all births take place in health facilities, because of biases the dimensions and direction of which cannot be determined. RAMOS use triangulation of different sources of data on deaths of women of reproductive age, including record review and/or verbal autopsy to accurately identify maternal deaths. Based on multiple sources of information, RAMOS are considered to be the best way to estimate levels of maternal mortality. Estimates derived from household surveys are usually based on information collected retrospectively about the deaths of sisters of the respondents and could refer to deaths that occurred an average of 12 years ago, and are subject to wide confidence intervals. For countries without any reliable data on maternal mortality, statistical models are applied. Global and regional estimates of maternal mortality are developed every 5 years, using a regression model.
Disaggregation
By age and parity, location (urban/rural, major regions/provinces), and socioeconomic characteristics (e.g. level of education, wealth quintile).
References
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http://www.who.int/classifications/icd/en/
WHO. International Classification of Diseases. 10th Revision. Geneva, World Health Organization, 2004. -
http://www.who.int/reproductive-health/publications/maternal_mortality_2000/index.html
WHO. Maternal mortality in 2000. Estimates developed by WHO, UNICEF and UNFPA. Geneva, World Health Organization, 2000
Database
None.
Comments
Maternal deaths are from an epidemiological perspective, relatively rare events, which necessitates large sample sizes for direct estimates of mortality levels via population surveys. In addition, their accurate identification is usually problematic, even with established registration systems. Many low-income countries have no or very little data and modelling is used to obtain a national estimate.