Elsevier

The Lancet

Volume 370, Issue 9595, 13–19 October 2007, Pages 1311-1319
The Lancet

Articles
Estimates of maternal mortality worldwide between 1990 and 2005: an assessment of available data

https://doi.org/10.1016/S0140-6736(07)61572-4Get rights and content

Summary

Background

Maternal mortality, as a largely avoidable cause of death, is an important focus of international development efforts, and a target for Millennium Development Goal (MDG) 5. However, data weaknesses have made monitoring progress problematic. In 2006, a new maternal mortality working group was established to develop improved estimation methods and make new estimates of maternal mortality for 2005, and to analyse trends in maternal mortality since 1990.

Methods

We developed and used a range of methods, depending on the type of data available, to produce comparable country, regional, and global estimates of maternal mortality ratios for 2005 and to assess trends between 1990 and 2005.

Findings

We estimate that there were 535 900 maternal deaths in 2005, corresponding to a maternal mortality ratio of 402 (uncertainty bounds 216–654) deaths per 100 000 livebirths. Most maternal deaths in 2005 were concentrated in sub-Saharan Africa (270 500, 50%) and Asia (240 600, 45%). For all countries with data, there was a decrease of 2·5% per year in the maternal mortality ratio between 1990 and 2005 (p<0·0001); however, there was no evidence of a significant reduction in maternal mortality ratios in sub-Saharan Africa in the same period.

Interpretation

Although some regions have shown some progress since 1990 in reducing maternal deaths, maternal mortality ratios in sub-Saharan Africa have remained very high, with little evidence of improvement in the past 15 years. To achieve MDG5 targets by 2015 will require sustained and urgent emphasis on improved pregnancy and delivery care throughout the developing world.

Introduction

Maternal mortality—ie, the death of a woman during pregnancy or in the 42 days post partum due to causes directly or indirectly associated with the pregnancy—has been a priority area for the global health and development community at least since the Nairobi Safe Motherhood Conference in 1987. That conference, attended by representatives from 50 developing countries and from key development agencies, has been followed by numerous international forums at which safe motherhood was on the agenda. The 2000 Millennium Summit established the improvement of maternal health as Millennium Development Goal (MDG) 5.1 The target of MDG5 is to reduce the maternal mortality ratio (defined as maternal deaths in a time period, usually 1 year, divided by the number of livebirths in the same period, and conventionally expressed per 100 000 livebirths) by 75% between 1990 and 2015; for a country to achieve this target requires an average decrease of 5·5% per year in the maternal mortality ratio.

Country estimates of maternal mortality are essential to inform national decisionmaking and resource allocation, to underpin advocacy efforts, and to stimulate research. Additionally, international development partners and donors rely on sound estimates to inform their own decisionmaking on resource allocation. Yet currently available country data vary greatly in quantity and quality and do not readily lend themselves to comparisons, either over time or between countries. The best way of reliably measuring maternal mortality is through a civil registration system that registers all deaths and provides medical certification of cause of death. However, even where such systems exist, vigilance is necessary to ensure that all maternal deaths are correctly classified; studies have shown maternal deaths to be under-reported.2, 3, 4, 5, 6 In countries lacking complete recording of adult deaths—eg, most low-income countries—alternative approaches are needed. Researchers have developed a range of alternative measurement strategies and data availability has increased over the past 15 years. Yet in countries representing a quarter of global births there remains little empirical basis for estimating maternal mortality.

UNICEF, WHO, and the UN Population Fund (UNFPA) have previously developed global, regional, and country estimates of maternal mortality for the years 1990, 1995, and 2000.7, 8, 9 In 2006 a new maternal mortality working group was established that included WHO, UNICEF, UNFPA, the UN Population Division, and the World Bank, as well as several outside technical experts, to develop new estimates of maternal mortality for 2005. As a starting point, this group reviewed a set of suggested improvements, prepared as part of an external review commissioned by WHO, to the methods that had been used for the 2000 estimates. In response to these suggestions and to questions posed by countries after the 2000 round of estimates, the working group agreed on ways to classify countries on the basis of data availability, on how to adjust data derived from different sources to enhance comparability across countries and across time, and on the specifications for the statistical model used to predict values for countries lacking appropriate data. Here, we describe the new methods used and present national, regional, and global 2005 estimates of maternal mortality. We also address the challenge of comparability of estimates over time and generate some broad conclusions about global and regional trends since 1990.

Section snippets

Methods

Our unit of analysis was the country. Countries have used a range of different data collection approaches to generate estimates of maternal mortality. Our analysis was restricted to nationally representative sources of data. Sources were identified in collaboration with countries through WHO, UNICEF, and UNFPA country representatives as well as from internationally coordinated survey programmes; our cutoff for the review of data sources was March, 2007. Different data sources require different

Results

We estimate that there were about 535 900 maternal deaths worldwide in 2005, and the maternal mortality ratio was about 402 maternal deaths per 100 000 livebirths (table 1). Most maternal deaths were concentrated in sub-Saharan Africa (270 500, 50% of deaths worldwide) and Asia (240 600, 45% of deaths worldwide); almost half (48%) of maternal deaths worldwide in 2005 was concentrated in just five countries: India (117 100), Nigeria (58 800), the Democratic Republic of Congo (32 300),

Discussion

Our results indicate that the worldwide maternal mortality ratio for 2005 is about 402 deaths per 100 000 livebirths, which represents about 535 900 maternal deaths in 2005. At the national level, estimated maternal mortality ratios range from below 10 deaths per 100 000 livebirths in most developed countries to as high as 2000 deaths per 100 000 livebirths in some developing countries. This huge difference in risk dwarfs differences for other commonly used health indicators, such as the infant

References (31)

  • H Atrash et al.

    Maternal mortality in developed countries: not just a concern of the past

    Obstet Gynecol

    (1995)
  • N Schuitemaker et al.

    Underreporting of maternal mortality in the Netherlands

    Obstet Gynecol

    (1997)
  • MH Bouvier-Colle et al.

    Maternal mortality estimation in France, according to a new method

    J Gynecol Obstet Biol Reprod (Paris)

    (2004)
  • United Nations. United Nations Millennium Declaration. Resolution adapted by the General Assembly, 55th Session of the...
  • MH Bouvier-Colle et al.

    Reasons for the underreporting of maternal mortality in France, as indicated by a survey of all deaths among women of childbearing age

    Int J Epidemiol

    (1991)
  • Perspectives in disease prevention and health promotion enhanced maternal mortality surveillance—North Carolina, 1988 and 1989

    MMWR Morbid Mortal Wkly Rep

    (1991)
  • Current trends maternal mortality surveillance—Puerto Rico, 1989

    MMWR Morbid Mortal Wkly Rep

    (1991)
  • National pregnancy mortality surveillance

    (1991)
  • Revised 1990 estimates of maternal mortality: a new approach by WHO and UNICEF

    (1996)
  • Maternal mortality in 1995: estimates developed by WHO, UNICEF, UNFPA

    (2001)
  • Maternal mortality in 2000: estimates developed by WHO, UNICEF and UNFPA

    (2004)
  • M Gissler et al.

    Pregnancy-associated deaths in Finland 1987–1994—definition problems and benefits of record linkage

    Acta Obstet Gynecol Scand

    (1997)
  • LA Turner et al.

    Under-reporting of maternal mortality in Canada: a question of definition

    Chronic Dis Can

    (2002)
  • D Karimian-Teherani et al.

    Under-reporting of direct and indirect obstetrical deaths in Austria, 1980–98

    Acta Obstet Gynecol Scand

    (2002)
  • Cited by (0)

    View full text