Improving prenatal nutrition in developing countries: strategies, prospects, and challenges

In developing countries, the health and nutrition of females throughout their entire life is affected by complex and highly interrelated biological, social, cultural, and health service-related factors. Rather than focusing exclusively on the prenatal period, we describe a life cycle approach to improving maternal nutrition, which goes beyond the traditional provision of nutrition services during pregnancy, by addressing risk factors that are present well before pregnancy, even before childbearing age. This approach involves specific policy initiatives and a "minimum package" program that is targeted at females. Policy actions and the components for effective implementation of the program are described. The prospects and challenges to be overcome-which include translating scientific knowledge into action, removing conceptual and implementational constraints, identifying biologically meaningful indicators for problem identification, and improving understanding of physiologic and social adaptation mechanisms-are discussed, as are persistent problems with health care delivery systems.

Undernutrition among Honduran children 12-71 months old

In 1996, the Ministry of Health of Honduras conducted a national micronutrient survey that included anthropometric measurements to determine the nutrition status of children 12-71 months old. Among the 1,744 children who participated, 38% of them were stunted, including 14% who were severely stunted; 24% were underweight, of which 4% were severely underweight; and 1% were wasted, of which 0.1% were severely wasted. The country can be divided into three groupings based on the level of stunting and underweight: 1) lowest prevalence: Tegucigalpa, San Pedro Sula, and medium cities; 2) medium prevalence: other urban areas, the rural north, and the rural south; and 3) highest prevalence: the rural west. Using logistic regression analysis, the important determinants of stunting were found to be: mother/caretaker's and father's schooling, source of water, the dominion (geographic location and strata) in which the child lived, and the "possession score" for ownership of such items as a radio, television, refrigerator, stereo system, and electric iron. The predictors for underweight were micronutrient status, diarrhea, maternal/caretaker's schooling, type of toilet, and possession score. Historical data indicate that the national prevalence of chronic undernutrition has changed little over the last 10 years despite the number of national food and nutrition plans implemented and the significant improvements in health services. It is possible that these positive interventions have been offset by the slow progress in economic development. Future nutrition interventions should take into account household-level perceived needs and priorities in order to set realistic nutrition targets.

Vitamin A deficiency and anemia among children 12-71 months old in Honduras

Vitamin A deficiency (VAD) and iron deficiency anemia (IDA) have been recognized as public health problems in Honduras for over 30 years. This paper, based on the 1996 National Micronutrient Survey on 1678 children 12-71 months of age, presents the results for vitamin A status and anemia prevalence, as well as the level of vitamin A in sugar at the household level. The results showed that 14% of the children were subclinically vitamin A deficient (plasma retinol < 20 micrograms/dL) and 32% were at risk of VAD (plasma retinol 20-30 micrograms/dL). These data indicate that VAD is a moderate public health problem in Honduras. Logistic regression analysis showed that children 12-23 months old living in areas other than the rural south of the country were at greatest risk of subclinical VAD. Infection, indicated by an elevated alpha-1-acid-glycoprotein level, increased the risk of subclinical VAD more than three-fold. Children from households that obtained water from a river, stream, or lake were at twice the risk of subclinical VAD compared with other children. That same doubled risk was found for children from a household with an outside toilet. VAD can be controlled by fortifying sugar. Retinol levels in sugar at the household level were about 50% of those mandated by Honduran law. There appears to be significant leakage of unfortified sugar into the market. This is particularly true in the rural north, where 33% of samples contained no retinol. Overall, 30% of children were anemic (Hb < 11 g/dL). Logistic regression analysis showed that children whose fathers lived with them but who had not attended at least grade 4 of primary school were at 33% greater risk of being anemic. Infection and being underweight increased the risk of being anemic by 51% and 21%, respectively. Many of the anemic children had not been given iron supplements, suggesting health care providers may not be aware that anemia is widespread among young children and/or know how to diagnose it.

Nutrition of Honduran mothers/caretakers

In 1996, the Honduran Ministry of Health conducted a national micronutrient survey of children 12-71 months old, which also included an assessment of the nutrition status of their mothers/caretakers. The 1,126 mothers/caretakers who participated in the survey tended to be short and plump. About 15% of them were at obstetric risk by virtue of their short stature and/or low body weight. About 9% had chronic energy deficiency (CED), but 27% were at least 20% overweight. CED was associated with socioeconomic indicators of poverty. Risk factors for being at least 20% overweight included being over 30 years old, not breast-feeding, having attended no higher than grade 4, 5, or 6 of primary school, coming from a wealthier household, and living in San Pedro Sula or medium-sized cities. Among the women surveyed, 26% of nonpregnant and 32% of pregnant mothers/caretakers were anemic. The likely principal cause of anemia was the low intake of bioavailable iron from food and, in some cases, excessive iron loss associated with intestinal parasites, especially hookworm. Only 50% of the mothers/caretakers participating in this study had received iron during their last pregnancy, and just 13% had received postpartum vitamin A. The results highlight the need to develop and implement an effective program to control iron deficiency anemia in women of reproductive age, including by fortifying such widely consumed foods as processed wheat and maize flour and by routinely administering iron supplements to high-risk groups. Postpartum vitamin A supplementation should be encouraged to protect both the mother and newborn infant against vitamin A deficiency.

Iron and folate fortification in the Americas to prevent and control micronutrient malnutrition: an analysis

Although there has been a remarkable decline in the proportion of malnourished children in Latin America, micronutrient deficiencies, especially iron deficiency anemia, remain significant public health problems. A substantial reduction in the prevalence of iron deficiency anemia is an important goal for the end of the decade. Interest in fortifying wheat flour and dry-milled maize flour is thus growing, and significant experience in the fortification of flours with iron and the B vitamins, including folate, is emerging. It is necessary to ensure that fortification levels and standards, legislation, and quality assurance and control measures are in place nationally and harmonized regionally.

Vitamin A deficiency in Latin America and the Caribbean: an overview

Vitamin A deficiency (VAD) has been known to exist in Latin America and the Caribbean since the mid-1960s; however, except for pioneering work by the Institute of Nutrition of Central America and Panama/Pan American Health Organization on sugar fortification in Central America, there was little interest in controlling it because of the low frequency of clinical findings. More recently, implications of the effect of subclinical VAD on child health and survival has generated increased interest in assessing the problem and a greater commitment to controlling it. The information available by mid-1997 on the magnitude of VAD in countries of the Region was extensively reviewed. Internationally accepted methods and cutoff points for prevalence estimations were used to compile information from relevant dietary, biochemical, and clinical studies carried out between 1985 and 1997 in samples of at least 100 individuals. VAD in the Region of Latin America and the Caribbean is mostly subclinical. The national prevalence of subclinical VAD (serum retinol < 20 micrograms/dl) in children under 5 years of age ranges between 6% in Panama and 36% in El Salvador. The problem is severe in five countries, moderate in six, and mild in four. There are no recent data from Chile, Haiti, Paraguay, Uruguay, Venezuela, and the English-speaking Caribbean. The population affected amounts to about 14.5 million children under 5 years of age (25% of that age group). Schoolchildren and adult women may also have significant VAD. Actions currently implemented to control VAD include (a) universal or targeted supplementation, with sustained high coverage rates through national immunization days in some countries; (b) sugar fortification, which is well established in El Salvador, Guatemala, and Honduras (a significant effect has been documented in Guatemala and Honduras) and is under negotiation in Bolivia, Colombia, Costa Rica (to be resumed), Ecuador, Nicaragua, and Peru; and (c) limited dietary diversification activities.

A packaged rice-based oral rehydration solution for acute diarrhea

In a 12-month community study in Ecuadorian preschool children, we compared a packaged rice-based oral rehydration solution (R-ORS) that contained 160 g of rice flour and 12 g of sucrose per liter as well as electrolytes and alpha-amylase, and required cooking before consumption, to the standard glucose-electrolyte oral rehydration solution (G-ORS) for the treatment of acute noncholera diarrhea. The reconstituted R-ORS had energy and protein contents of 620 kcal/L and 12g/L, respectively, and an osmolarity of 230 mosm/L. In all, 156 cases were treated with the R-ORS and 144 with the standard G-ORS. Cases treated with R-ORS had a significantly shorter duration of diarrhea (p < 0.0001; median; 34 h versus 48 h), a lower number of stools (p < 0.001; median; four versus seven), and a greater weight gain after 4 days of treatment (p < 0.05; mean; 1.6% versus-0.2%) than those treated with G-ORS. ORS and total liquid intakes tended to be higher with the R-ORS. The two ORS were equivalent for the correction of mild dehydration and the maintenance of normal hydration status.

[Vitamin A deficiency and actions for its prevention and control in Latin America and the Caribbean, 1994]

Since the 1970s, the prevalence of protein-energy malnutrition has declined in the countries of Latin America and the Caribbean. However, micronutrient deficiencies, especially of iodine, iron, and vitamin A, have not diminished to the same extent. Based on clinical criteria, vitamin A deficiency continues to be a public health problem in Brazil, the Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, and Nicaragua. This deficiency is also common in poor communities in Bolivia, in some parts of Mexico and Peru, and among indigenous groups in Panama. Trends in general health and nutrition indicators in Colombia, Cuba, Guyana, Paraguay, and Venezuela suggest the need to update information on vitamin A deficiency in those countries. At the close of the 1980s, increasing interest was manifested in reducing vitamin A deficiency in the Region of the Americas; this interest has led to epidemiologic studies, national and regional meetings, and the implementation of plans and interventions at the local, national, and regional levels. In the medium and long term, a permanent solution to the problem of vitamin A deficiency can be attained through sustained economic and social development, accompanied by specific actions to diversify diets in order to increase consumption of foods rich in vitamin A, fortification of popular foods, and nutritional education. In the short term, temporary measures--such as periodic administration of vitamin A supplements to high-risk groups--can be applied.

Age-specific responsiveness of weight and length to nutritional supplementation

Evaluation of the responsiveness of weight and length to supplementary feeding shows that the two periods of greatest response coincide with weaning (ages 3-6 mo) and peak incidence and duration of diarrheal disease (ages 9-12 mo). Analyses were done for seven consecutive nonoverlapping intervals comparing children randomly assigned to receive supplemental feeding from birth to age 36 mo or to serve as control subjects. Absolute responsiveness was greatest between ages 3-6 mo; supplemented infants grew 0.61 cm more and gained 162 g more than did unsupplemented infants (p less than 0.005). Relative to rates of growth, responsiveness was greatest between ages 9 and 12 mo (the period of peak diarrheal prevalence), followed by ages 3-6 mo (the period of weaning). Responsiveness to supplementation is thus directly related to age-dependent risk patterns for malnutrition. Targeting supplementation programs to coincide with periods of high nutritional risk should maximize their effectiveness in reducing malnutrition, though caution should be exercised to avoid disruption of breast-feeding.

Long-term effects of food supplementation and psychosocial intervention on the physical growth of Colombian infants at risk of malnutrition

280 Colombian infants at risk of malnutrition were randomly assigned to 1 of 4 experimental groups formed by the presence/absence of 2 interventions: (1) food supplementation for the entire family, from mid-pregnancy until the target child was 3 years old, and (2) a twice-weekly home-visiting program to promote cognitive development, from birth until age 3. All families received free medical care and were studied prospectively. At 3 years of age, children who had received food supplementation averaged 2.6 cm and 642 grams larger than controls. Home visiting and supplementation together reduced the number of children with severe growth retardation. 3 years after intervention (age 6), supplementation effects remained. Children in the home visit condition had become larger than controls, by 1.7 cm and 448 grams. The interactive effect to reduce stunting was marginally significant at this age, and the overall distribution of scores was improved. Other results suggest that changes in family functioning as well as biological mechanisms account for the observed pattern of results.

Nutritional supplementation: effects on child stunting because of diarrhea

Research has shown that the positive effect of nutritional supplementation on child growth in malnourished populations is small relative to the large negative effect of diarrheal disease. To test the hypothesis that the effects of supplementation and diarrhea are synergistic in that supplementation modifies the negative effect of diarrhea on linear growth, length and diarrheal morbidity were compared at 36 mo of age for two cohorts of Colombian children: supplemented from birth and unsupplemented. Among unsupplemented children diarrhea was negatively associated with length. Among supplemented children diarrhea had no effect on length and differed from that of unsupplemented children. Thus, supplementation completely offset the negative effect of diarrheal disease on length. Targeting supplementation programs to the critical period of high diarrheal prevalence among infants and young children should increase the effectiveness of such programs in preventing growth retardation associated with diarrhea.

A new method for estimating a standardized prevalence of child malnutrition from anthropometric indicators

Although anthropometric indicators are widely used for assessing the nutritional status of children, lack of consensus on the cut-off points for prevalence estimates has precluded the use of standard analytical methods in population surveys. A simple method for estimating a standardized prevalence of child malnutrition from anthropometric indicators is presented. The method is based on comparing the distribution of the indicator with that of the normalized NCHS reference population, the underlying assumption being that both distributions are nearly normal. Standardized prevalence is defined as the proportion of cases in the observed population that is outside the normal distribution of the reference values, which can be estimated from the mean and standard deviation of the standardized Z-scores of the population, by using a formula based on the mathematical properties of the normal probability curve. A reference table is included which provides computer-estimated prevalence rates for different mean Z-scores and standard deviations of normally distributed anthropometric indicators.

The effects of nutritional supplementation on the diets of low-income families at risk of malnutrition

Protein-energy malnutrition in synergism with infection is a major problem for most developing countries, and inadequate food consumption is a critical factor in its development. Food supplementation programs can improve nutrient consumption but may also have unintended consequences. Changes in consumption of foods as well as nutrients need to be identified and evaluated. The effects of a food supplementation program on family diet patterns and protein-energy intake were investigated using data from nutritionally at risk families in Bogota, Colombia. Because food supplements are income transfers they need to substitute for purchases of similar food items. However, the results of our investigation reveal that food supplementation based on familiar foods that are part of the usual family diet are consumed in substantial quantities and result in net nutrient consumption increases. The food supplementation program increases consumption of preferred food items and introduces greater diversity into the family diet. These effects are enhanced when combined with a home education program.

Sex related effects of nutritional supplementation during pregnancy on fetal growth

Nutritional supplementation of low income women during pregnancy increased birth weight significantly only in the male offspring. No differences by sex were apparent in the amount of supplementation, length of gestation or maternal characteristics known to be associated with birth weight. Regression analysis revealed a significant supplementation by sex interaction. The fetal growth curve of the supplemented males was higher and roughly parallel to the curve of females, and showed an effect of supplementation prior to 35 weeks of gestation. These findings and those of other authors support the hypothesis that fetal growth of males towards the end of pregnancy is more rapid and hence more susceptible to adverse environmental influences than that of females. This is reflected in a reduction of the difference in birth weight in favor of males observed in well-nourished populations. It is postulated that male subjects therefore exhibit sensitivity to nutritional supplementation of their mothers during pregnancy.

Nutritional supplementation, maternal education, and cognitive development of infants at risk of malnutrition

Infants born to families at risk of malnutrition were studied prospectively from the beginning of the 3rd trimester of the mother's pregnancy until the child reached 3 yr of age to ascertain the effects of nutritional supplementation and/or a maternal education program on their cognitive development. Four hundred thirty-three families were assigned randomly to six groups: group A served as a control; group B received the supplement from the age of 6 months to 3 yr; group C received the supplement during the 3rd trimester of pregnancy and the first 6 months of the child's life; and group D received the supplement throughout the entire study period. In addition, group A1 was enrolled in a maternal education program but received no nutritional supplement and group B1 received both treatments. The Griffiths test of infant development was administered at 4, 6, 12, 18, 24, and 36 months of age, and the Corman-Escalona Einstein scale was administered at each age up to 18 months. Children who received food supplementation performed better than those who did not, especially on subtests that were primarily motoric. The effect of food supplementation on behavior appeared to be contemporaneous. In addition, the treatment effects were more pronounced for girls than for boys in this sample. Although these interventions reduced the gap in cognitive performance between lower and upper socioeconomic classes, a disparity nevertheless remained by the end of the study.

Food supplementation of pregnant women at risk of malnutrition and their newborns' responsiveness to stimulation

Pregnant women at risk of malnutrition were enrolled in a health care programme in Colombia, South America, and were randomly assigned to a group receiving supplementary food or to a control group at the beginning of the third trimester of pregnancy. There were no differences between the groups in social or nutritional variables. Supplementary food was found to have an effect on infants' reactions to mild aversive stimulation and their degree of irritability. Infants born to non-supplemented mothers generally responded more irritably to removal of a nipple and to the application of a cold disc to the abdomen. Female infants of non-supplemented mothers also recovered more slowly than the supplemented group from crying in response to both removal of nipple and the cold disc. The findings are believed to show a maturational effect of maternal diet during the last trimester of pregnancy.

Nutritional supplementation and the outcome of pregnancy. II. Visual habituation at 15 days

Colombian women at risk of mild-to-moderate malnutrition were enrolled in a health care program and randomly assigned into nutritional supplementation and control groups at the beginning of the third trimester of preganancy. One hundred unsupplemented and 144 supplemented infants were tested at 15 days of age: a 2X2 checkerboard was presented eight times followed by a single presentation of a 6X6 checkerboard. Unsupplemented infants showed less initial attention followed by slower habituation and higher levels of movement than the supplemented infants. The observed effect of maternal nutritional supplementation during the last trimester of pregnancy on new-born attention was interpreted to be maturational in nature.

Nutritional supplementation and the outcome of pregnancy. I. Birth weight

Colombian women at risk of malnutrition were enrolled in a health care program and randomly assigned to supplementation and control groups at the beginning of the third trimester of pregnancy. The net dietary intake increments resulting from supplementation amounted to 155 cal and 20 g of protein per day. Supplementation had a significant effect on the mean birth weight of male infants, but not that of female infants; the mechanisms responsible for the sex differences remain to be elucidated. The randomized trial design of the experiment and the documented similarity between the experimental and control groups at the onset permit the conclusion that the observed differences were caused by the food supplementation program. The effect of supplementation on maternal weight gain and the association of the latter with birth weight strongly suggest that improved maternal nutrition mediated the effect on birth weight.