Using nutrition to reduce maternal deaths
Maternal mortality is a tragedy in social, economic and public health terms. WHO and UNICEF have noted that of the 585,000 yearly maternal deaths around the world, the vast majority are preventable. About 80 per cent of these deaths are the result of five direct obstetric causes: haemorrhage, infection, obstructed labour, unsafe abortion and a convulsive disorder in late pregnancy called eclampsia.7
As already noted, obstructed labour is more likely to occur among women who were stunted in childhood (Fig. 13). It is estimated that anaemia may be responsible for as much as 20 per cent of maternal mortality, particularly those deaths from haemorrhage and possibly infection. Anaemia also increases the risk of morbidity and mortality associated with any major surgical intervention, including Cae sarean section.
Programmes already exist to reduce anaemia in pregnant women. More work is needed, however, not only to make iron/folate supplementation pro grammes more effective, but also to improve the treatment and prevention of malaria and hookworm. Both of these are conditions that also contribute to maternal anaemia.
Even if an adequate nutritional status were achieved in adolescent girls and women before their first pregnancy, this would never eliminate the need for good medical care in pregnancy and childbirth. But some day it may help reduce the tragic burden of maternal mortality and the need for certain medical interventions. Some of the connections between nutrition and maternal mortality suggested below are not yet definitively demonstrated or part of programme activities, but they hold great promise for the future. A few are especially worth mentioning:
Even given the many known benefits of good vitamin A status, it is nonetheless remarkable to find that improving the vitamin A status of pregnant women whose intake of the vitamin is low also dramatically reduces maternal mortality (Panel 1). Deadly infections in pregnancy, as in childhood, find a formidable adversary in vitamin A. The use of low-cost, low-dose vitamin A capsules as well as improvements in diet make it highly probable that this new research will be easily incorporated into programmes.
Zinc deficiency, increasingly recognized as widespread among women in developing countries, is associated with long labour, which increases the risk of death. Severe zinc deficiency is also believed to impair foetal development in a number of ways. Zinc is important for the synthesis of hormones and enzymes essential to childbirth -- especially estrogen-dependent functions such as expulsion of the placenta and proper contraction of uterine muscles during birth -- as well as for immune-system development. A number of studies around the world have found that zinc supplementation has reduced complications of pregnancy. Several studies are under way that will soon help define the impact of improved zinc status on pregnant women.
It has long been known that iodine deficiency in women increases the risk of stillbirths and miscarriages. And there is evidence that, in highly iodine-deficient areas, another result of this deficiency may be increased maternal mortality through severe hypothyroidism.
A recent study in the United States showed that calcium supplementation did not reduce the risk of hypertension in pregnancy that could result in death, but a number of experts have suggested that supplementation might reduce this risk in areas where women are especially calcium deficient.
Folate deficiency, now well known to induce neural-tube birth defects if it is present during the first month of pregnancy, may also represent a risk for maternal morbidity and mortality, as well as increase the risk of low birthweight.
The clear message emerging from these connections is that improving women's nutritional status -- by increasing their intake of micronutrients as well as their overall food consumption, and by taking steps to reduce their workload and improve their access to health care -- may offer considerable, low-cost benefits in reducing maternal deaths. But there is still no international consensus on the benefits to be gained by supplementation during pregnancy with nutrients other than iron and folate.
The real challenge is to reach women well before they become pregnant -- indeed, to help adolescent girls achieve the best nutritional status possible before they enter their reproductive years. This would not only help reduce maternal mortality but would also reduce the prevalence of low birthweight, the risk of birth defects and the rates of stillbirths and early infant mortality. All of these remain scientific and programmatic challenges, along with the imperative of ensuring that women's health is positioned high on the health and development agendas of all countries.
Breastfeeding: Good for mothers' health too
In addition to the nutritional status of adolescent girls and women, there is another important connection between nutrition and maternal mortality. A number of studies have shown a strong link between the early initiation of breastfeeding and reduced risk of postpartum haemorrhage.
Initiating breastfeeding immediately following birth, as most women do in baby-friendly hospitals, stimulates the contraction of the uterus and reduces blood loss. For this reason, the continuing spread of the Baby-Friendly Hospital Initiative should also contribute to the reduction of maternal mortality.
Photo: Interaction and stimulation are essential to sound nutrition as well as intellectual and emotional development. In China, a boy delights in his meal and the attention of his aunt.
In recent years, research has also demonstrated that this immediate post-partum benefit is by no means the only way in which breastfeeding can improve women's health. A recent large-sample study in the United States demonstrated that women who breastfed their children had a lower risk of breast cancer in the pre-menopausal period, and the longer they breastfed, the lower the risk.8 These results show that protecting, promoting and supporting breastfeeding has benefits for women that go beyond the remarkable effects, already well understood, that protect their children from illness and death.
Prevention of chronic diseases
Chronic degenerative diseases are largely regarded as diseases of affluence. In industrialized countries, improvements in living standards and health care have led to increased life expectancy, allowing people to live long enough to develop such chronic illnesses. Chronic diseases are also associated with the sedentary lifestyle and over-abundant diet prevalent in many industrialized nations.
Arguments are being made, however, that these chronic diseases in large measure may also be diseases of poverty -- particularly poverty early in life and during foetal development. The hypothesis is particularly intriguing in light of the fact that ischaemic heart disease is projected to be the world's leading cause of death and disability in the year 2020.9
Professor David Barker and his colleagues at the Medical Research Council (MRC) Environmental Epidemiology Unit in Southampton (UK), first raised the "foetal origins of adult disease" hypothesis over a decade ago, noting a link between low birthweight and the incidence of cardiovascular disease among middle-aged men and women born in the United Kingdom.10
Since then, over 30 studies around the world have indicated that low-birthweight babies who were not born prematurely have a higher incidence of hypertension later in life than those with a normal birthweight,11 independent of their social class and such adult risk factors as smoking, drinking and overeating.
Professor Barker and his colleagues speculate that maternal dietary imbalances at critical periods of devel opment in the womb can trigger a redistribution of foetal resources, affecting a foetus's structure and metabolism in ways that predispose the individual to later cardiovascular and endocrine diseases. The correlation between low birthweight and later cardiovascular disease and diabetes may arise from the fact that nutritional deprivation in utero 'programmes' a newborn for a life of scarcity. The problems arise when the child's system is later confronted by a world of plenty.14
In central India, an ambitious study has been funded by UK Welhome Trust and coordinated by Dr. Ranjan Yajnik at the King Edward Memorial Hospital Research Centre in Pune (India) and Dr. Caroline Fall at the MRC Environmental Epidemiology Unit. It is exploring the impact that a mother's nutrition may have on the development of diabetes, high blood pressure and coronary heart disease in her offspring when they reach adulthood. The results could resolve some of the uncertainties about causation of chronic illness, offering nutritional information relevant to both developing and industrialized countries.
The study has followed over 800 women through pregnancy, monitoring foetal growth, maternal weight gain and biochemical indicators of nu tritional status.15 The nutritional value of the women's daily food intake -- including calorie, protein and micro nutrient content - was measured and recorded. Within 24 hours of birth, both infant and placenta were weighed and other body measurements made.16 Almost one third of the nearly 800 infants born during the study were classified as low birthweight, under 2.5 kg.17 An interesting early finding suggests that birthweights are most strongly associated with the size of the mother -- not just her weight gain during pregnancy, a well-known determinant of newborn size, but also her weight, height, percentage of body fat and head circumference before conception. The weight and body mass index of many of the women before pregnancy suggested chronic undernutrition. The study also suggested that women's diet during pregnancy did not appear to have influenced foetal size substantially, although regular con sumption of two particular items -- green leafy vegetables and dairy products -- was associated with larger birth size. These early findings lend support to the premise that building a sturdy baby depends on good nutrition for the expectant mother throughout her life.
The children from the Pune study are growing up in a society of increasing urbanization and prosperity. Urban dwellers in India are already five times more likely to develop diabetes than their rural relatives,18 and those who have migrated to industrialized countries like the United Kingdom die in significantly larger numbers from coronary heart disease than their indigenous white counterparts.19
In 1999, the first of the children in the study will be tested for signs of glucose intolerance and insulin resistance; these are early hints of diabetes that have already been noted in children of low birthweight in Pune.20 Soon after, blood pressure monitoring will begin in an effort to look for initial signs of hypertension. As the study progresses, findings can be related back to birth size, foetal growth and maternal diet before and during pregnancy. From an undertaking of this magnitude, clear evidence may emerge about the importance of improving maternal nutrition as a means of preventing chronic later-life disease in children - before these children have children of their own.
New ways to reduce malnutrition deaths in emergencies
The sheer extent of mild and moderate malnutrition makes these conditions responsible for much more sickness and death globally than does severe malnutrition. But a severely malnourished child -- usually defined as under 70 per cent of the median weight-for-height reference or having oedema (water retention and swelling) at least in the feet -- is at very high risk of death, and requires prompt and intensive care in a health facility.
Until recently, health professionals dealing with severe malnutrition in emergency situations or in large hospitals in poor countries had been using an approach practised for years. The protocol was to treat infectious conditions, correct rehydration and feed, at least in the early stages, with high-energy milk -- usually a combination of dried skim milk, vegetable oil and sugar. In the last few years, however, with the help of WHO and the benefit of the experience of a number of NGOs specializing in this field, the new protocol is improving the treatment of severe malnutrition.
While the new protocol retains some elements of former standard practices, there are significant changes. The milk now recommended for the early stages of therapeutic feeding, for example, is enhanced by the addition of both oil and a vitamin and mineral mix, which addresses the special micronutrient imbalance that accompanies severe malnutrition. Called F-100 because it gives 100 kilocalories per 100 grammes, the milk optimizes the chance for rapid weight gain and the eventual recovery of a severely malnourished child.
Another important change is a new recommendation calling for modification of the standard oral rehydration salts (ORS) to address the special electrolyte needs of severely malnourished children. The use of standard ORS has been known to increase risk of heart failure and sudden death among certain severely malnourished children. The revised ORS reduces that risk. Known as ReSoMal (rehydration solution for malnutrition), it contains more potassium and different concentrations of elements from those in standard ORS.
The new protocol for the care of the severely malnourished also emphasizes elements that have been known by nutrition workers for some time, but perhaps not well enough to be integrated into regular practice. These include the need for rapid attention to clinical factors, such as low body temperature (hypothermia) and low body sugar (hypoglycaemia), as well as to less strictly medical factors such as meeting malnourished children's great needs for emotional support, intellectual stimulation and play. Experienced emergency nutrition personnel working in places such as the Great Lakes region of Central Africa and the Democratic People's Re public of Korea have adopted this method and noted how quickly it helps reduce mortality. One challenge is to ensure that supplies of the appropriate high-energy milk and rehydration solution are steady and sufficient (Panel 19).
New ways to measure malnutrition
Much of the new knowledge described above will contribute to effective actions to reduce malnutrition and related conditions. But even when actions are effective, assessing their impact is often difficult. Measuring malnutrition initially can also pose problems -- and make it difficult to place the issue on the policy and programme agenda.
There is thus a need for assessment and analysis techniques that are low in cost, produce rapid results and are easy to use and understand. Here are some of the promising new tools:
A simplified way to look for vitamin A: Population-level surveys of vitamin A status have been a particular challenge. In the past, when it was thought that the main impact of vitamin A deficiency was damaged eyes and blindness, population surveys of vitamin A status involved examining children's eyes for early signs of damage. Now that it is understood that this deficiency has lethal consequences on a subclinical level -- that is, at levels of deficiency that do not yet show up as damage to the eye -- more sensitive methods of detecting its presence are needed.
Most of the national or regional vitamin A surveys that have been conducted in recent years have used blood retinol as the principal indicator of vitamin A status. There are some diffi culties with the interpretation of this indicator, and it is expensive and difficult to collect and analyse the venous blood samples needed for these surveys.
A new technique that promises to be easier, cheaper and less invasive is 'dark adaptometry'. This method, which has been tested and found effective in several field situations,21 takes advantage of the fact that in very early stages of vitamin A deficiency the ability of the pupil of the eye to constrict under illumination is impaired. By flashing a simple hand-held light at one pupil and covering the other, the degree of impairment of the pupillary reflex can be estimated. It is hoped that this simple method, which is non-invasive, will become widely available soon.
'Dipsticks' for iodine deficiency: Iodine deficiency disorders (IDD) can be assessed in populations by palpating goitres, but this method requires a high level of training and is less useful as goitres begin to disappear with better access to iodized salt.
Since iodine excreted in the urine is a good indicator of iodine consumed, IDD can be reliably detected by analysing urine samples. Many countries have undertaken urinary iodine surveys, which involve collecting samples, preserving them carefully and sending them to a laboratory for analysis in a central location.
A new technique may eliminate some of those steps and much of the cost. A reagent-treated testing strip or 'dipstick' now being developed will simplify the procedure by allowing the iodine content of urine to be analysed and read directly on the spot without transporting samples to a laboratory. It is hoped that this tool will soon be available for field surveys.
Improved test kits for iodized salt: Simple iodized salt test kits have helped make salt-testing a community affair. Anyone can use the small plastic bottles of test solution that cause salt to turn blue if it is iodized, and some countries have distributed these kits to schoolchildren, teachers and community workers. The test kits, however, have a limited shelf life, and they do not distinguish very sensitively among levels of salt iodization. Work is now under way to improve the test kit in both these respects and make it an even more useful assessment tool.
Computerizing anaemia surveys: Thanks to computer chips, assessment of anaemia at the population level is becoming easier. There have been methods for some time to assess peripheral blood (from a fingertip, for example) without sending the samples to a laboratory, but some of them are slow and inaccurate.
Portable electronic haemoglobinometers are now available, however, that enable blood to be drawn easily from a finger into a small cuvette that is inserted directly into a machine that gives a digital read-out of the precise haemoglobin level in a few seconds. The wider use of these machines in population surveys will help to raise awareness of the enormous magnitude of the anaemia problem.
The importance of good nutrition for girls and women is affirmed by a mid-1980's study of pregnant Guatamalan women, which found that the risk of having an intrapartum Caesaren delivery was 2.5 times higher in short mothers than in tall mothers. Short stature in women is often a consequence of poor growth in early childhood.
Source: Kathleen M. Merchant and Jose Villar, "How do material and newborn sixe affect risk of foetal ditress and intrapartum Caesarean delivery?" (draft).
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