Despite previous estimates of maternal mortality that showed little progress, this study, Maternal mortality for 181 countries, 1980–2008: a systematic analysis of progress towards Millennium Development Goal 5, reveals that maternal deaths fell from more than 500,000 annually to fewer than 350,000 over the past 30 years. The work was conducted by researchers at IHME in collaboration with the School of Population Health at the University of Queensland.
There were 342,900 maternal deaths – deaths of women during pregnancy, childbirth, or in the 42 days after delivery – worldwide in 2008, down from 526,300 in 1980. The global maternal mortality ratio (MMR) – the number of women dying for every 100,000 live births – declined from 422 in 1980 to 320 in 1990. It reached 251 in 2008 and is on pace for further declines. The MMR has been declining at an annual rate of about 1.3% since 1990. From 1990 to 2008, the rates of yearly decline in the MMR varied between countries, from an 8.8% annual decrease in the Maldives to a 5.5% annual increase in Zimbabwe.
Developing countries, in particular, have made substantial progress toward the Millennium Development Goal set in 2000 of reducing the MMR. Although only 23 countries are on track to achieve the target of lowering the MMR by 75% between 1990 and 2015, countries such as Egypt, China, Ecuador, and Bolivia have been achieving accelerated progress.
Nearly 80% of all maternal deaths are concentrated in 21 countries, and six countries account for more than half of all maternal deaths: India, Nigeria, Pakistan, Afghanistan, Ethiopia, and the Democratic Republic of the Congo.
Eight low-income countries have seen annual increases in the MMR over the period 1990 to 2008, including Afghanistan and Zimbabwe, as have several high-income countries, such as the United States, Canada, and Norway. At least part of the increase in high-income countries appears to be due to changes in the way maternal deaths are reported. Mothers in the US now die at a higher rate than in most other high-income countries, four times the rate of Italy and three times the rate of Australia.
Progress in reducing maternal mortality has been slowed by the ongoing HIV epidemic. Nearly one out of every five maternal deaths – a total of 61,400 in 2008 – can be linked to HIV, and many of the countries with large populations affected by HIV have had the most difficulty reducing their maternal mortality ratio.
Beginning in 2007, researchers analyzed vital registration data, censuses, surveys, and verbal autopsy studies. They constructed a database of 2,651 observations of maternal mortality for 181 countries for the period from 1980 to 2008. They developed new analytical methods to generate estimates of maternal deaths and the MMR for each year between 1980 and 2008. They then explored the sensitivity of their data to model specification and checked the predictive validity of the methods.
Maternal mortality remains a significant challenge for societies working to improve health outcomes worldwide. The topic has become the focus of several international conferences and is one of the goals that grew out of the Millennium Declaration in 2000, which set a target of reducing the MMR by three-quarters from 1990 to 2015. Previous attempts to measure the extent of maternal mortality have shown stagnation in the trend over time. As part of IHME’s mission to measure the major health problems worldwide and to track the performance of societies addressing these problems, researchers gathered the largest amount of data ever analyzed for a maternal mortality analysis.
Recommendations for future work
Researchers hope to gather more data from more recent censuses, health surveys, and verbal autopsies to develop a keener understanding of how much of the rise in maternal deaths can be traced to better reporting and how much may be due to other factors.
Since the publication of the study, IHME has organized trainings in our new maternal mortality methods at workshops in Brazil and Sri Lanka. The researchers intend to continue to share the new methods they have created for estimating maternal mortality to help governments, development agencies, and aid organizations better understand trends in the MMR.
Because of the findings showing the sharp increase in MMR in some countries as a result of HIV, more research is needed to find the right policy interventions for dealing with HIV infection in pregnant or post-partum women. This may include access to antiretroviral drugs.
Detailed policy reviews are needed to understand the differences between countries that have had substantial declines in MMR, including Egypt, Romania, Bangladesh, India, and China, and other countries that have not been as successful. In some cases, this might require comparisons of pairs of countries. For example, from 1990 to 2008, the MMR decreased 1.9% every year in Mexico and 3.9% in Brazil. Both are similar in size, economics, and social makeup, and both have made policy commitments to reduce maternal mortality. Brazil, however, has lowered the MMR at nearly twice the rate as Mexico.
In order to gather more data on maternal deaths, countries with complete vital registration systems could consider adding a checkbox to the death certificate to identify women who were pregnant at the time of death or within 42 days before death.