Maternal mortality. Photo credit: PlosONE

Source: PlosONE

By Matthew Owens

A new study published in the open access scientific journal PLoSONE has shown that the maternal mortality rate (MMR) in Chile has dramatically reduced over the last 50 years and now compares favourably with the rest of the American continent. Study figures suggest the rate now surpasses that of most regional countries including that of the US.


“Concepción, Chile, May 5 – A scientific analysis of 50 years of maternal mortality data from Chile has found that the most important factor in reducing maternal mortality is the educational level of women. “Educating women enhances women’s ability to access existing health care resources, including skilled attendants for childbirth, and directly leads to a reduction in her risk of dying during pregnancy and childbirth,” according to Dr Elard Koch, epidemiologist and leading author of the study.

The research entitled  “Women’s Education Level, Maternal Health Facilities, Abortion Legislation and Maternal Deaths: a Natural Experiment in Chile from 1957 to 2007” was conducted on behalf of the Chilean Maternal Mortality Research Initiative (CMMRI) and published in the Friday, May 4 issue of PLoS ONE.

Using 50 years of official data from Chile’s National Institute of Statistic (1957-2007), the authors looked at factors likely to affect maternal mortality, such as years of education, per capita income, total fertility rate, birth order, clean water supply, sanitary sewer, and childbirth delivery by skilled attendants. They also analysed the effect of historical educational and maternal health policies, including legislation that has prohibited abortion in Chile since 1989, on maternal mortality.

During the fifty-year study period, the overall Maternal Mortality Ratio or MMR (the number of maternal deaths related to childbearing divided by the number of live births) dramatically declined by 93.8%, from 270.7 to 18.2 deaths per 100,000 live births between 1957 and 2007, making Chile a paragon for maternal health in other countries. “In fact, during 2008, the overall MMR declined again, to 16.5 per 100,000 live births, positioning Chile as the country with the second lowest MMR in the American continent after Canada and with at least two points lower MMR than the United States” said Koch.

One of the most significant findings is that, contrary to widely held assumptions, making abortion illegal in Chile did not result in an increase in maternal mortality. In fact, after abortion was made illegal in 1989, the MMR continued to decrease from 41.3 to 12.7 per 100,000 live births (69.2% reduction). “Definitively, the legal prohibition of abortion is unrelated to overall maternal mortality rates” emphasized Koch.

The variables affecting this decrease included the predictable factors of delivery by skilled attendants, complementary nutrition for pregnant women and their children in the primary care clinics and schools, clean facilities, and fertility. But the most important factor and the one that increased the effect of all others was the educational level of women. For every additional year of maternal education there was a corresponding decrease in the MMR of 29.3 per 100,000 live births.

The picture for Chile includes a transition of leading causes of death along with an accelerated decline of fertility and delayed motherhood. Koch explained that direct causes –those directly attributable to pregnancy condition– were the rule before 1990, but from then, indirect causes –i.e. non-obstetric chronic conditions such as hypertension and diabetes among others– arise as the most prevalent, hindering the decline on maternal mortality.

“This study uncovers an on-going ‘fertility paradox’ in maternal health: education is the major modulator that has helped Chile to reach one of the safest motherhood in the world, but also contributes to decrease fertility, excessively delaying motherhood and putting mothers at risk because of their older age.” Thus, an emerging problem nowadays “is not a question of how many children a mother has, but a question of when a mother has her children, specially the first of them” concluded Koch.”

Elard Koch

Professor Elard Koch

Professor  Koch, who is Principal Investigator and Director of Research at Universidad Católica de la Santísima Concepción and Universidad de Chile, spoke to about the significance of the ground-breaking study.

Relevance of the work

This is a landmark study since it shows an in-depth analysis of a large time series, year by year, of maternal deaths and their determinants, including years of education, per capita income, total fertility rate, birth order, clean water supply, sanitary sewer, and childbirth delivery by skilled attendants, and including simultaneously different historical policies. In this sense, it is a unique natural experiment conducted in a developing country. Thus, there is a rigorous analysis controlled by multiple confounders. It is not a matter of circumstantial or anecdotal evidence, but it is a matter of scientific data representing real vital events whose methodology has been published for the first time in a peer reviewed scientific journal.

As described in our paper, the study shows that the most important factor promoting the decrease in maternal mortality is the number of years in women’s education. Nevertheless, the study also places Chile as the second safest country in the American continent, following Canada, for maternal health during pregnancy and childbirth. The ranking was elaborated using official vital data from several countries during 2008, including the US. Noteworthy, when comparing official data with those of the most recent technical report from the World Health Organization (WHO), significant overestimations were found. For instance, the WHO global report overestimates maternal mortality ratios 28.3% for the US, 33.3% for Canada, 48.6% for Mexico, 57.6% for Chile, and 76.3% for Argentina. Thus, the WHO report underestimates the progress of several developing countries in improving maternal health.

Further directions of the research

The powerful statistical methodology developed to perform the published analysis allowed for simultaneous comparison of several factors and confounders, year by year. In addition we identified two clear changes in the slope of the decline from 1957 to 2007. Between 1965 and 1981, there was an accelerated reduction of 84% in the MMR of approximately -13.29 per 100,000 live births each year (rapid phase). Between 1981 and 2003, the slope became less pronounced, at -1.59 per 100,000 live births each year (slow phase). All mortality causes declined in parallel, but the proportion of maternal deaths due to indirect causes increased during the slower phase.

We noted that there is a transitional threshold in the decrease of maternal mortality ratio approximately situated between 40 and 50 maternal deaths per 100,000 living births separating the rapid and slow phase in the downward trend. A possible explanation for this transition from a rapid to a slower decline on maternal mortality is that, before 1990, causes of maternal death were of obstetric origin or directly attributable to complications of childbirth, such as haemorrhage, sepsis and obstructive labour. Since 1990, however, there has been a major change in the proportion of maternal death causes in Chile, moving towards pre-existing chronic conditions, unrelated to pregnancy. In fact, nowadays 40% of all causes of maternal deaths are related to indirect causes, such as hypertension, diabetes, obesity and cardiovascular diseases. This change suggests the apparition of a more complex residual pattern of maternal morbidity, which requires specialized, immediate medical services for decreasing the MMR trend.

More complexity is added to this issue due to the presence of an unavoidable “fertility paradox” in maternal health: education is the major modulator that has helped Chile to reach one of the safest motherhoods in the world, but also contributes to decreased fertility, excessively delaying pregnancy and putting mothers at risk because of their older age. Childbearing at advanced ages emerged progressively in Chile from 1985 and it continues to rapidly increase. We think that this paradox hinders further improving maternal health in Chile and, most likely, in several developed and developing countries. The actual deleterious effect of these phenomena requires further research in Chile and especially in developed nations where maternal mortality is increasing, such as in the case of the U.S.

Implications for policy

One of the interesting features of the article is that several policies were considered when interpreting trends observed in maternal mortality: 1) the passing of a law that mandates free education to a minimum of eight years for all Chilean population in 1965; 2) implementation of an extensive prenatal primary care program with a family planning component at the end of the 1960’s; and 3) prohibition of abortion in 1989. Completeness and quality of Chilean data provided a unique way to test, in hindsight, the relevance of such policies on maternal health.

In light of the analysed data, policies aimed to increase women’s school years, facilitate universal access to improved maternal health facilities (early prenatal care, delivery by skilled birth attendants, postnatal care, availability of emergency obstetric units and specialized obstetric care), provide complementary nutrition for pregnant women and their children in the primary care network and schools, and improve the sanitary system ―i.e. clean water supply and sanitary sewer access– greatly favoured maternal health. Furthermore, it is confirmed that women’s educational level appears to have an important modulating effect on other variables, especially promoting the utilization of maternal health facilities and modifying their reproductive behaviour. Consequently, we propose that these policies outlined in different United Nations’ Millennium Development Goals and implemented in different countries may act synergistically and efficiently decreasing maternal deaths in the developing world.

In contrast to wide held assumptions, abortion banning did not influence overall maternal mortality rates. Although our study definitively ruled out any deleterious influence of abortion prohibition on the maternal mortality trend, it cannot be immediately concluded that solely making abortion illegal is a direct causal factor for decreasing maternal mortality. Thus, one complex and important question remains: Does prohibition of abortion save lives? We can address this important issue from different perspectives.

First, from a Public Health view, restrictive laws are hypothesized to cause a dissuasive effect on the population, similar to restrictions on tobacco or alcohol use. We observed that reduction of maternal mortality in Chile was paralleled by the number of hospitalizations attributable to complications of clandestine abortions: while over 50% of all abortion-related hospitalizations were attributable to complications of clandestine abortions during the 1960’s decade, this proportion decreased rapidly in the following decades; indeed, only 12-19% of all hospitalization from abortion can be attributable to clandestine abortions between 2001 and 2008. These data suggest that throughout time, restrictive laws may have a restraining effect on the practice of abortion, promoting its decrease. In fact, Chile exhibits today one of the lowest abortion-related maternal deaths in the world, displaying 92.3% further decrease from 1989 and 99.1% accumulated decrease over fifty years.

Second, from the perspective of the human life, especially if a developing country is looking for simultaneously protecting the life of the mother and the unborn, a plausible hypothesis after the Chilean study is that abortion restriction may be effective when combined with public policies adequately implemented to increase the education level of women and improve access to maternal health facilities. A restrictive law may discourage practice, which is suggested by the decrease of hospitalizations due to clandestine abortions estimated in Chile.

Finally, from the perspective of protecting the human life from the very beginning, evidently, abortion restriction saves many lives, in contrast to countries where first-trimester elective –on demand– abortion is allowed, because in these countries all the unborn lose their lives. It is just a matter of simple logical reasoning if you are looking for protecting the human life during all the stages of the human development.

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