Rationale and definition:
The maternal mortality ratio is the annual number of maternal deaths from any cause related to or aggravated by pregnancy or its management (excluding accidental or incidental causes) during pregnancy, childbirth, or within 42 days of termination of pregnancy, per 100,000 live births per year. This indicator reflects the capacity of health systems to effectively prevent and address the complications occurring during pregnancy and childbirth. It may also highlight inadequate nutrition and general health of women and reflect the lack of fulfillment of their reproductive rights resulting in repeated and poorly spaced pregnancies.
The maternal mortality rate is the number of maternal deaths in a population divided by the number of women of reproductive age. It captures the likelihood of both becoming pregnant and dying during pregnancy (including deaths up to six weeks after delivery).
As data systems improve, it will be important to disaggregate by age, geographic location (e.g. urban vs. rural), and income level.1
Comments and limitations:
Both metrics are difficult to measure as vital registration and health information systems are often weak in developing countries. The ratio does not capture deaths during pregnancy or the puerperium, which may be due to complications from pregnancy or delivery, as rate does, which is why we suggest measuring both.
Preliminary assessment of current data availability by Friends of the Chair:
Primary data source:
Complete vital statistics registration systems are the most reliable data source, but these are rare in developing countries so household surveys are often used.
Potential lead agency or agencies:
WHO, UN Population Division (UNPD), UNICEF, and World Bank maintain databases on maternal mortality.
See WHO website on maternal and perinatal health.