|Food and Nutrition Bulletin Volume 04, Number 3, 1982 (UNU, 1982, 64 p.)|
The term "maternal nutrition" focuses attention on women as mothers, on their nutritional status as it relates to the bearing and nurturing of children. At the same time, women also play vital, if often unacknowledged, roles in their families, communities, and societies. However, the poor nutritional status of many women in the world today compromises their capacity to meet the vigorous demands of their multiple roles as mothers and productive workers. Lack of sufficient food or the deficiency of a specific nutrient, such as iron, is clearly implicated in contemporary maternal malnutrition. Often, however, a heavy work-load, made yet more difficult by limited access to basic resources (e.g., water and fuel), pushes a woman with marginally adequate food intake into a state of undernutrition. Thus, it is necessary to look at maternal nutrition in the broad context of the women's life circumstances.
When a woman begins life as an undernourished infant, with frequent illness and poor nutrition during childhood, she arrives at maturity in a less than optimal state to undertake pregnancy and lactation. As the conditions that produce malnutrition continue to affect her, both she and her offspring, as well as the larger community, are further disadvantaged through a vicious intergenerational cycle of poverty and undernutrition.
Figure 1 illustrates some of the main influences on, and the outcomes of, maternal nutritional status. From it can be deduced the main problems in any particular situation, the possible remedial measures, and the gaps in our knowledge that hinder progress. In dealing with these topics no attempt is made to go into technical detail, rather the intention is to highlight areas on which we must concentrate in the future.
MATERNAL NUTRITIONAL NEEDS AND PROBLEMS IN DEPRIVED POPULATIONS
The needs during pregnancy for such nutrients as calcium, vitamin A, thiamine, niacin, riboflavin, ascorbic acid, vitamin D, vitamin B. folate, iron, protein, and energy have been assessed by various FAD/WHO expert groups. The requirements for energy and protein are in the process of being re-examined.
Currently, estimates of nutrient requirements are based on healthy, mature women, who arrive at conception adequately nourished and who are only moderately active during their pregnancy. They are frequently applied to poorly nourished mothers of a smaller body size, who perhaps have not even completed their own growth. Their nutritional status and stores may already be inadequate; they must bear the drain of parasitism plus the stress of frequent infections; and rarely is there any reduction in their heavy physical workload.
Thus, published figures of additional nutritional requirements in a normal pregnancy bear little relation to the needs of many Third World mothers. Indeed, perhaps the most surprising thing is not that such women grow old before their time and have a reduced life expectancy, but rather that they are able to survive so long, cope with many tasks, and continue to bear and nurse children. However, it is interesting to note that, other than measuring weight gain or subcutaneous fat during pregnancy, a large proportion of the studies of maternal nutrition focus mainly on the mother's ability to produce a live child of sufficient size and her capacity to produce sufficient milk to feed it. There has been too little attention given to the impact of malnutrition before and during pregnancy on the mother herself.
The primary maternal nutritional deficiencies found in deprived populations can be summarized as follows:
a. Energy deficiency-primarily occasioned by poor availability of food but also conditioned by anorexia and stress of infections plus the high requirements of physical labour.
b. Iron-deficiency anaemia-coupled with folate deficiency in some areas. Again the main cause is too low an intake of foods containing iron/folate, exacerbated by the increased needs of pregnancy. In hostile environments there is the added burden of reduced absorption, defective haemopoeisis, and increased blood loss.
c. Vitamin A deficiency-occasioned by low intake. As carotene is the main source for Third World mothers, vegetable consumption habits and seasonal availability are crucial. The most striking adverse effects are usually seen in the offspring of deficient mothers after the infants are weaned.
d. Iodine deficiency-leading to endemic goitre occurs in areas where the iodine content of the soil, water, and plants is low, especially in the presence of goitrogens, and where foods from outside the area are not consumed. Adverse effects on the mental performance of the offspring is a main concern.
e. Deficiency of other micro-nutrients, such as thiamine, niacin, and zinc, may still occur in certain geographic areas.
ACTIONS TO IMPROVE MATERNAL NUTRITIONAL STATUS
In general, intervention strategies employed in developing countries have not yielded the benefits expected. Partly this is because of the many interrelated factors that influence a mother's nutritional status, ranging from her physiological utilization of food and nutrients during pregnancy and lactation, through the socio-economic influences on food availability and her energy expenditure, to the cultural and educational conditions that affect her ability to utilize available resources. On the other hand, severely limited resources have usually permitted only restricted coverage by any intervention and necessitated a fairly narrow approach.
On the basis of present knowledge, both long-term and short-term interventions can be envisaged. The former are by far the more important, but short-term measures must be taken simultaneously to alleviate the current situation.
The cause of poor nutrition and ill health in many countries is poverty. It is the responsibility of all development workers, including those in the field of nutrition, to participate in the decision-making process in whatever way they can to ensure that development results in a more equitable distribution of available resources, especially as these affect the nutrition and health of women. The particular long-term interventions selected must be based on local priorities and feasibility. Some examples follow.
With legislation it is important to recognize two aspects: the development of legislation per se and the infrastructure to enforce these laws. Legislative action in the following areas would ultimately affect the nutritional status of women and hence have impact on problems of maternal nutrition.
Equal rights and opportunities: There must be equal rights under law for both sexes, enabling women to seek and obtain work for equal pay and so to improve income and nutrition.
Marriage and family laws need to deal with the following two areas, among others:
- Age of marriage: There are countries where more than half of first pregnancies occur in girls below 18 years of age, before the adolescent has reached her full physical, mental, and social maturity, with deleterious effects on the mother and child. Legislation should be formulated setting the minimum age of marriage at an age compatible with local rates of maturation. Attention must be paid to enforcement in the many countries that already have such laws but do not apply them.
- Dissolution of marriage: Women should have equal right to divorce and share the common property, so that their nutritional and social security are not endangered by the changed social situation.
Child labour laws should ensure that young girls are not exposed to undue demands likely to stunt their growth, impair their health, or affect their reproductive capacity.
Conditions of work and employment for women must include:
- the right to gainful employment;
- flexibility in the work situation to allow for changes in her physiological status;
- the right to paid maternity leave, benefits, and child allowances; maternity leave should be sufficiently long to ensure that the infant is breast-fed at least during the early months;
- provision of time and facilities to allow continuation of breast-feeding and infant care after the mother's return to work.
Family planning: There should be access to services for child-spacing. In view of the high rate of illegal abortions and their deleterious effect on women's health and reproductive capacity, the formulation and enforcement of abortion laws is necessary.
Social toxicants (drugs and stimulants): Legislation is needed to protect women from the adverse effects of social toxicants, particularly during pregnancy and lactation.
Women who receive even a minimal basic education are generally more aware than those who are illiterate of the need to utilize available resources for the improvement of the health (particularly the nutritional status) of themselves and their families. It is therefore imperative that young girls be enrolled into compulsory primary school education. Opportunities should also be given to adult women to take part in non-formal education. Health and nutrition education should form an integral part of the education process for both boys and girls. In areas where cultural and religious beliefs seriously affect the mother's intake of food and or nutrients, every educational effort should be made to overcome these adverse practices. Special consideration must be given to ensure that intrafamilial food distribution safeguards the mother's nutritional status.
National agricultural policy should ensure a sufficiency of food production and an efficient system of storage and distribution. Inflationary trends tend to erode the purchasing power of the poorer families. Measures are therefore especially necessary to ensure that the poorer families are able to obtain their basic food requirements.
Appropriate Technology to Reduce Material Work- load
Poor access to water, fuel, and other basic household necessities encroach on the mother's energy, time, and health. Employment of traditional and modern appropriate technology should be implemented to reduce women's energy expenditure and release time for self-improvement, child care, and community participation.
Implementation of internationally advocated approaches to ensure the accessibility of health care through the primary health-care approach will have a major impact on the nutrition and health status of the mother. Of particular importance are:
- the nutritional education and training of the traditional birth attendant and primary health-care workers;
- access to MCH services to ensure a long interbirth interval, providing time for the woman to build up her nutrient stores and care for the child; also by immunization and early treatment reduce mortality and morbidity among women and children;
- provision of environmental sanitation to reduce some of the endemic diseases such as hookworm infestation that lead to severe anaemia in women.
While the effect of long-term interventions is awaited, it is important that immediate action be taken to alleviate the acute nutrition-related problems. Each country will have to make its own analysis to determine which problems are the most urgent and the most feasible methods of ameliorating conditions.
Adequacy of the Energy Supply
To date, food supplementation for pregnant and lactating women, outside of experimental settings, has not achieved the objectives of increasing infant birth weight and lactation performance. Nevertheless, in view of the documented energy deficits in the diets of pregnant and lactating women, short-term efforts should be made to increase their intake by the following means:
- Encouraging redistribution of available food within the family. The feasibility of such efforts will vary from culture to culture and depend greatly on the effectiveness of the health or other social worker in the community's setting, as will overcoming negative attitudes and practices that lead to food restriction.
- Making it a prime national and local policy objective to ensure that the poorest in any community have the ability to obtain an adequate entitlement of food. Inputs will vary from encouragement of local production in a subsistence economy to control of the commercial market in more developed circumstances.
- Introducing appropriate technology to reduce the mother's workload and investigating whether this might be more feasible than increasing her intake.
Where a deficit exists despite the implementation of the above, food supplementation may be employed, directed only to the at-risk mother, taking into account the possibility of food leakage and the displacement of existing family foods. Supplementation assumes an adequate health infrastructure for its delivery.
Nutrition education should emphasize the maximum utilization of foods that prevent anaemia, and primary health-care service should provide simple protection or treatment of other causes of anaemia such as hookworm. Provision of iron and folate preparations is effective in preventing and treating the deficiencies, but requires an efficient, well-utilized service and long treatment periods.
Vitamin A Deficiency
Vitamin A levels in breast milk can be improved by the postpartum administration of a single massive oral dose of vitamin A that can be given by the traditional birth attendant (or community health worker). Massive doses during pregnancy are not recommended, although smaller therapeutic doses can be used to correct any deficiency. In areas where it is feasible, encouraging the growth of green leafy vegetables in kitchen and community gardens will provide a source of carotene-rich foods. iodine Deficiency
Where goitre and cretinism are prevalent, every effort must be made to introduce the iodization of salt. In circumstances where this is not possible, or where the iodized salt does not reach segments of the population, injections of a depot iodine should be given to all women of reproductive age before conception. This will provide protection for four or five years. However, this procedure requires a basic health infrastructure to implement it effectively.
Other Vitamin and Mineral Deficiencies
In certain geographic areas beri-beri, rickets, osteomalacia, or other deficiencies still afflict women. While an improved and varied diet will remove these hazards, in the short-term, where food fortification is impractical, it may be necessary to resort to the provision of supplements through the health service, particularly during pregnancy and lactation.
GAPS IN OUR KNOWLEDGE CONCERNING MATERNAL NUTRITION
Despite the amount of investigation that has been conducted in the nutrition field, it is astonishing to discover the extent of our ignorance about different facets of maternal nutrition. The gaps in our knowledge are sufficiently numerous to seriously inhibit the design, conduct, and assessment of measures to remedy maternal malnutrition. Below are listed some of the principal areas of concern at different stages of pregnancy and lactation and their practical implications.
The Ability to Assess Maternal Nutritional Status
Currently, there are no widely accepted field-applicable methods for measuring relative states of nutrition and their functional effects in adults, irrespective of gender. Consequently, we lack an adequate basis for assessing the prepregnancy state of nutrition against which change can be measured during pregnancy (anthropometric measures are non-specific). This problem limits the possibility of identifying women who could benefit from intervention programmes, and it also seriously affects our ability to evaluate the physiological and social effect of such programmes on the mother and the conceptus.
Nutritional Requirements for Pregnancy
Considerable information is available on nutrient requirements necessary to support pregnancy under ideal conditions, but knowledge is lacking on how different consumption and preparation practices affect availability of nutrients and their utilization by the pregnant women living in conditions of deprivation. Homeostatic adjustments are known to occur during pregnancy, but the limits of adaptability for various nutrients and the relationship to genetic and/or other biologic and environmental factors are not clear. Hence, it is not possible to establish with confidence guidelines for nutrient needs of individuals from different ethnic groups, living in varied environments with different degrees of activity. Without precise knowledge of the limits of adaptability, it is not possible to evaluate homeostatic adjustments that may occur in various conditions, nor to assess the consequences for the quality of maternal life, including future pregnancies.
Effect on Mother of Dietary Supplementation during Pregnancy
Evaluation of the effectiveness of maternal supplementation programmes have focused on their influence on birth weight and lactation performance, neglecting possible benefits to the mother's health and quality of life, in both the short and the long term. The benefits evaluated in these terms appear to have been minimal or difficult to demonstrate, thus the physiological and public health significance of supplementation has been questioned. In view of their costs, there is need for better information on how these programmes may benefit the mother directly and improve her ability to perform many roles, such as family and child care, participation in social, educational, and community activities, and performance in the labour force.
Feasibility of Improving Maternal Diet without Improving Total Family Diet
Previous programmes have established that it is possible to improve maternal diets with respect to certain specific nutrients such as iron, vitamin A, and iodine, without improving the total family diet. Present experience suggests that in food distribution programmes it is difficult to reach the mother as a specific target without improving the diet of the whole family. We lack knowledge of how to design broad-based intervention programmes that will specifically reach the mother and be cost effective.
Efficiency of Maternal Replenishment at Different Levels of Intake
Pregnancy and lactation place added demands for energy and nutrients that, if not met, will deplete the maternal body. Frequent repetition of this cycle without an adequate interval and diet in between is likely to have cumulative effects deleterious to both the mother and her future children. We lack knowledge of the extra food needs and the optimal interval between births that would allow full recovery. This hinders the formulation of a rational policy for family planning on the basis of health considerations.
The Timing of Supplementary Feeding
Information is lacking on the critical periods before and during pregnancy at which supplementation will maximally affect the mother's own health status and the development of new maternal tissue to support reproductive functions, including foetal development and future lactation performance. Identification of an optimal period could influence the design and cost-effectiveness of programmes for mothers.
Role of the Placenta in Nutrient Utilization
The human foetus enjoys a large measure of protection against the effects of a poor maternal diet. An explanation for this protective effect may be found in the altered maternal hormonal environment, brought about by the endocrine function of the developing foeto-placental unit, which seems to regulate the utilization of energy and the nutrients. Although this is of more immediate scientific than applied interest, there is need to:
- elucidate the transfer mechanisms of nutrients through the foeto-placental unit;
- determine the impact of variations in size of placenta, development of villi, infection, and anomalies of the transfer mechanisms;
- determine the effects of improved energy and nutrient utilization by the foeto-placental unit on the health and nutritional state of mothers with poor dietary intakes.
Effects of Dietary Supplementation on the Foetus
Supplementation of malnourished mothers during pregnancy does influence birth weight, although the magnitude of the effect is limited. Insufficient information is available on the influence of supplementation during pregnancy on functional performance of the new-born, including developmental status such as immune competence, biochemical maturation, and neurological function. The few studies that have shown some benefits are confounded by supplementation of the babies after birth. Consequently, the cost-effectiveness of maternal supplementation for subsequent benefit to their infants cannot be estimated.
Insufficient Milk Syndrome
Failure to lactate or milk insufficiency is the most common reason given for artificially feeding a baby, especially in industrial societies. Yet, in many parts of the world it is important for the health of babies and the nutritional needs of mothers to be able, before the onset of lactation, to assess the potential capacity to produce breast milk. This would allow the design of appropriate counselling or educational programmes and the planning of supplementary feeding. Therefore, there is a need to:
- determine the proportion of mothers who have a physiological or anatomical impediment to breast-feeding;
-clarify mothers' perceptions of breast-milk sufficiency (or insufficiency) and the factors that influence them; this would need to include psychological, physiological, socio-economic, and environmental factors and the linkages among them;
- identify simple but reliable indicators that can predict lactational performance. These could range from the family history of breast-feeding, through a personality profile, to the physical appearance or changes in the breast.
Influence of Long-Term Lactation
Prolonged breast-feeding is characteristic of many population groups. Durations of up to two and three years are not unknown. On the other hand, elsewhere recommendations are being proposed that breast-feeding be continued as long as possible, with appropriate introduction of supplementary foods. Little is known, however, about the effect of prolonged lactation on the health and nutrition of the mother. This is extremely important in the case of populations where malnutrition or undernutrition is endemic. Nutritional depletion of the mother can occur in prolonged lactation, while conversely this may lengthen the birth intervals and delay the drain of the next pregnancy. There is a need to determine where the most favourable balance lies, as this may influence policy.
Lactation while Pregnant
Mothers in some parts of the world continue breast-feeding while pregnant. Given the increased nutritional needs as a result of pregnancy and simultaneous lactation, more research needs to be undertaken to identify any possible adverse effects on the health of the mother and on foetal development. This is not regarded as an urgent problem, save in some localities.
Lactation and Menstruation
Although prolonged lactation can usually be expected to delay the return of menstruation, many mothers continue to lactate after menstruation recommences. Especially in populations where anaemia is common, the combined loss of nutrients through menstrual loss and breast-feeding may have an adverse impact on the health and well-being of the mother. Study of the possible interrelationships among menstruation, lactation, maternal debilitation, and the quality or quantity of breast-milk would be of considerable scientific interest.
The side-effects of hormonal contraceptives on the quantity and quality of breast milk are increasingly causing concern, as is their impact on amenorrhoea, infertility, and the growth of teenage mothers. Clarification is required on the secretion of these hormones or their metabolites in breast milk, their effects on the suckling infant, and their influence on the absorption or utilization of specific nutrients in the lactating mother's diet.
Frequent suckling and intensity of suckling have been identified as important factors in maintaining high levels of prolactin, continued lactation capacity, and much better child spacing.
Both frequency and intensity, however, may be associated with the nutritional status of the mother, i.e., mothers whose volume of milk is low at any one feed will possibly not satisfy the infant and compensate by more frequent feeding, which, in turn, is accompanied by vigorous suckling. Alternatively, they may give complementary feeds that may also influence suckling vigour and frequency. From a programmatic point of view, it is important to know whether frequent suckling is independent of suckling vigour and also whether improved nutritional status in the mother will result in less frequent suckling. It is also important to identify the effects on prolactin levels of suckling hunger (i.e., desire to nibble on the breast) as opposed to feeding hunger (i.e., suckling on the breast primarily as a source of food).
Evidence is rapidly accumulating on the adverse effect of alcohol and smoking on foetal growth development. There is a need to focus more attention on their influence on the mother's health and capacity to lactate. Studies should be extended to cover the effects of potentially toxic substances widely used in many parts of the world-e.g., quat or khat in the Horn of Africa, or pan in Asia. Virtually no information is available on their effect on the mother, foetus, or neonate.
The Intergenerational Effect
In subjective terms, much has been said about the cumulative effect of childbearing in adverse circumstances. Indeed, a summation of the foregoing gaps in knowledge could be said to contribute to the "intergenerational effect." Yet it is justifiable to emphasize the result of immature arrival at pregnancy in unfavourable conditions, the poor start this gives to the offspring, and the burden carried over to the next generation. It is important to attempt to quantify this intergenerational effect if only to emphasize the importance of ascertaining, in both preventive and remedial teems, the needs of the immature or nutritionally deficient female who becomes pregnant.
Utilization of Risk Factors
While actions to improve nutrition should be foreseen at any time in the reproductive life of a women, it is important to be able to identify those at risk of malnutrition as early as possible.
In the case of individuals, anthropometric and other clinical methods need to be complemented by other tools. The use of risk factors in identifying pre-disposition to malnutrition and related complications could be particularly suitable for the primary health-care approach. Too little is known about the validity, as indicators of risk, of previous pregnancy experience, demographic background, socio-economic profile, work behaviour, and other such characteristics.
From the point of view of public health planning and early identification of at-risk populations, little work has been done to systematize the use of social and other risk indicators that do not require clinical examination. Such characteristics as socio-economic profile, access to and types of foods, seasonal availability of foods, work patterns, fertility patterns, educational levels, access to and work involved in obtaining water and fuel, or environmental characteristics such as waste-disposal facilities and practices and infectious diseases patterns deserve consideration. Controlled testing of the validity of these and other characteristics as indicators of predisposition to malnutrition are urgently required.
ACC Sub-committee on Nutrition
STATEMENT ON INFANT FEEDING
At its eighth meeting, held in Bangkok, Thailand, 15-19 February 1982, the ACC/SCN noted with satisfaction the very intense efforts being made to protect and promote breast-feeding worldwide. It wishes to reaffirm that satisfactory growth and development of the infant and young child depend on good maternal nutrition, adequate breast-feeding, timely complementary feeding, and appropriate weaning. These are universal goals applicable to all countries and to all social groups.