Among women of reproductive age in developing countries, complications of pregnancy and childbirth are the major cause of death and disability. According to World Health Organization (WHO) estimates, for each year in the 1990s there were about 515,000 deaths world-wide from pregnancy-related causes, the vast majority (99%) occurring in Africa, Asia, and Latin America. Of all the health indicators monitored by the United Nations, the biggest disparity between developed and developing countries is in maternal mortality. The World Bank reports that an estimated 28 million years of healthy life are lost each year in developing countries due to maternal health conditions.
Even though there is agreement on the leading causes of maternal deaths and the magnitude of the problem, there is considerable disagreement and uncertainty about how to define, measure, and reduce maternal mortality.
Definitions and Levels
WHO defines a maternal death as "the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration or site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes" (WHO, 1992). Maternal deaths are divided into direct and indirect obstetric deaths, with direct obstetric deaths accounting for approximately three-fourths of all maternal deaths. The main causes of direct obstetric deaths are hemorrhage, unsafe abortion, eclampsia, infection, and obstructed labor. Indirect obstetric deaths are those related to conditions that are either pre-existing or exacerbated by pregnancy, such as malaria, anemia, hepatitis, and increasingly, HIV/AIDS. A potential source of definitional confusion is that in 2001, the U.S. Centers for Disease Control and Prevention (CDC) defined the term "pregnancy-related death" as "one that occurs during pregnancy or within 1 year of its end and is a result of complications of the pregnancy or a condition that was aggravated by the pregnancy." This is equivalent to the WHO definition of maternal death, except that the time frame is 365 days, rather than 42 days.
Statistics constructed from data on maternal deaths include: the maternal mortality ratio (maternal deaths per 100,000 live births); the maternal mortality rate (maternal deaths per 100,000 women of reproductive age, per year), and the lifetime risk (the probability that a woman will die of maternal causes). The maternal mortality ratio is sometimes erroneously called the maternal mortality "rate," creating confusion.
Lifetime risk is often used to illustrate the disparities between the developed and developing worlds. It takes into account both the risk of death that a woman faces each time she becomes pregnant and the total number of pregnancies she would expect to have over the course of her life. Calculated for a population or a cohort of women, lifetime risk thus depends on both the maternal mortality ratio and the total fertility rate, both of which are higher in developing countries. In many countries the lifetime risk of dying of pregnancy-related causes is staggeringly high. For example, WHO estimates lifetime risk as 1 in 13 women in West Africa, compared to 1 in 3,900 in Northern Europe. Other regional maternal mortality statistics are shown in Table 1.
Data on maternal mortality are difficult and expensive to gather, requiring nearly complete registration of deaths or demographic surveys with large sample sizes as well as accurate reporting of cause of death. For most developing countries only estimates are available.
An alternative to gauging the level of maternal mortality is to measure the availability, utilization, and quality of life-saving obstetric services (known as emergency obstetric care, or EmOC). UNICEF
and Columbia University have developed indicators of these service dimensions. They rely on the records kept by health facilities and existing estimates of population size by birth rates, and so can be built into existing record-keeping systems. Known as the UN Process Indicators, they were jointly issued by UNICEF, WHO and UNFPA in 1997. Their use has highlighted the large deficits in the availability and functioning of obstetric care services.
Maternal deaths used to be very common in Europe and the United States. As recently as the early-twentieth century, maternal mortality rates and ratios were as high in the United States as they are in areas of the developing world of the twenty-first century. Even though there were improvements in living conditions in the late 1800s and early 1900s, maternal mortality did not decline. The historian Irvine Loudon notes that it was not until the mid-1930s that a steep and steady decline in maternal mortality rates began. In 1915 the maternal mortality ratio in the United States was 608 maternal deaths per 100,000 live births; in 1933 it was 619, but by 1950 it had fallen to 83. The same pattern prevailed in other western countries. The great decline in maternal deaths in the West was not primarily due to gradual socioeconomic development (e.g., nutrition, education) but to the introduction of effective means of coping with obstetric complications: antibiotics for infection, blood transfusions for hemorrhage, and safer surgical techniques.
Strategies for Reducing Maternal Deaths
In the developing world, the major approaches to reducing maternal mortality are through nutritional programs, programs aimed at predicting or preventing serious obstetric complications, and programs aimed at ensuring treatment for complications.
Nutritional interventions. Serious anemia probably increases a woman's risk of dying of obstetric complications although the existing studies are flawed. Longstanding programs have sought to reduce anemia by giving women iron and folic acid supplements during pregnancy. However, serious anemia is generally due to a combination of factors, including not only iron deficiency, but malaria, intestinal parasites, and other ailments. Therefore, it is unlikely that iron folate supplementation alone will reduce maternal deaths.
More recently, vitamin A supplementation has been proposed as a way to reduce maternal deaths. The supporting evidence for this was a study in Nepal, which found a lower incidence of pregnancy-related deaths (from all causes up to 12 weeks after delivery) among women who received vitamin A. However, the meaning of this study is unclear since the greatest difference in relative risk of death was not in infections (which would support a biological explanation) but in accidents.
Predicting and preventing complications. Programs aimed at predicting and preventing serious obstetric complications include the training of traditional birth attendants (TBAs) and antenatal care. Despite the intuitive appeal of such programs, their potential effectiveness is much less than is generally thought. This is partly the result of the biological nature of the major complications: while some of them may be detected early (e.g., a substantial proportion of serious pre-eclampsia cases, and some cases of malposition of the fetus), they still require medical treatment to prevent harmful or even fatal progression.
Despite the great effort put into it, there are insurmountable obstacles to making this "risk approach" effective. While high-risk groups (e.g., very young women or those with a bad obstetric history) can be identified, the individual women who will develop complications cannot be. Moreover, most maternal deaths will take place in the low-risk group, simply because it is so much larger than the high-risk group. Thus, focusing on high-risk groups takes attention away from most of the women who will die.
Ensuring treatment for complications. Even though most life-threatening obstetric complications cannot be predicted or prevented, they can be effectively treated. Consequently, ensuring access to adequate emergency obstetric care is the central requirement for reducing maternal deaths. Other effective initiatives for reducing maternal mortality include increasing the use of contraception (since it reduces the number of pregnant women, and thus the number of women at risk of maternal death) and improving access to safe abortion procedures. Complications of unsafe abortion are the only major cause of obstetric deaths that is almost completely preventable, as experience in developed and developing countries has shown.
In recent years those concerned about high maternal mortality rates have had high hopes for programs aimed at increasing skilled attendance at delivery in developing countries, but there remain substantial questions about the potential of this initiative. If skilled attendance is interpreted as increasing women's access to treatment of complications, then it may well help reduce maternal deaths. If it only means training peripheral health workers to attend normal deliveries, with no feasible medical backup, then it is unlikely to make a difference in current high rates of maternal death.
Improving access to emergency obstetric care does not necessarily require building new hospitals or training new cadres of workers. Much can be achieved by improving the functioning and utilization of existing facilities and personnel. To a significant extent, this is a problem of policies, priorities, and management, not of resources. For example, there are countries where there are not enough obstetricians or anesthesiologists to post them in rural hospitals, and yet general physicians, nurses, and midwives are not permitted or trained to give life-saving care to women with complications of pregnancy or delivery, or to administer simple forms of anesthesia.
Once adequate emergency obstetric care is provided in district hospitals and health centers, there emerge numerous opportunities to improve the utilization and quality of services with the help of nongovernmental organizations, community groups, and professional organizations. But without accessible services, no amount of community education or mobilization can save the lives of women with hemorrhage, eclampsia, or obstructed labor.
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