Hernán L Delgado

Maternal Nutrition and Fetal Growth in Developing Countries

The incidence of low birth weight ( ≤ 2.5 kg [5.5 lb]) is excessive in rural and urban low socioeconomic groups in preindustrialized countries (Fig 1). Since the large part of the population in these countries is in this socioeconomic stratum, low-birth-weight infants constitute a large proportion of the total newborn population. About 3 million infants born in Latin America alone during 1973 were of low birth weight. Since most of them presumably were full-term newborns, their low weights reflected fetal growth retardation. Low-birth-weight infants have a higher mortality during the first year of life than do infants of normal birth weight. 1,2 In addition, they show impaired mental development. 3,4 It is possible that this impairment influences their ability to develop into functioning adults. Influence of Maternal Nutrition on the Proportion of Low-Birth-Weight Babies Experiments in animals have shown that severe caloric or protein malnutrition in the mother delays fe

The Use of Arm Circumference in Simplified Screening for Acute Malnutrition by Minimally Trained Health Workers

The most commonly used measures for detecting protein energy malnutrition (PEM) in children are difficult for functionally illiterate personnel to make on a routine basis in poor rural households. Consequently arm circumference (AC) has been suggested as a simplified tool for field screening of PEM by minimally trained health workers. This study was designed to investigate the observer reliability of AC with respect to conventionally used indices of weight for height and weight for age. The project was set in 4 Indian villages in Guatemala where public health conditions are similar to those found in poor rural areas in many developing countries; 127 children ages 12 to 60 months were screened. A plastic measuring tape was used to obtain AC in centimeters and all measurements were taken on the same day. The principal implication is that under field conditions minimally trained workers make fewer and smaller errors in screening children with AC than with either weight for age or for height. The difference between community workers (promoter) and trained anthropometrists measurements as well as the variability between promoters suggest that training and follow-up of promoters are necessary for AC to be used effectively. In addition the analysis presented in this paper indicates that for this population AC was as reliable as weight for age and more reliable than the compounded weight for height measures. It is recommended that AC be used in nutrition surveillance and in programs of extension of coverage of public health services.

Relationship between family land availability and nutritional status

A study of the relationship between occupation, land owned and/or rented by the family and nutritional status of two‐ and three‐year‐old children was conducted in four rural Guatemalan villages. Families were divided into three occupational groups: salaried agricultural workers, farmers, and skilled workers and merchants. Nutritional status was defined in terms of weight for age. There was a tendency for the children of skilled workers and merchants to have the lowest prevalence of moderate malnutrition. It was found that 76 percent of families classified as farmers controlled less than five manzanas (one manzana = 0.7 hectares). The relative risk of having moderate malnutrition was 2.3 times greater in the two‐ and three‐year‐old children of families with access to less than two manzanas than in those with access to more than five manzanas.

Effect of moderate maternal malnutrition on the placenta.

The results of two studies of the influence of moderate maternal malnutrition on the weight and chemical characteristics of the placenta are discussed. In the first study, two groups of pregnant women of high and low socioeconomic status from Guatemala City were studied. Socioeconomic status was defined by family income, educational level of the mother, and environmental sanitary conditions. Both groups were very similar with respect to age, parity, gestational age, and absence of severe disease during pregnancy. The average placental weight in the low socioeconomic group was 15 per cent below that of the high socioeconomic group and there was a consistent association between the postpartum maternal weight and placental weight. There were no differences between the two groups regarding placental concentration of fat, protein, water, ash, hemoglobin, and DNA; hydroxyproline and fat concentration were significantly lower in the low socioeconomic group. The hypothesis that the difference in placental weight observed between the two groups was primarily due to maternal nutritional status was tested in the second study by means of nutritional intervention in four rural villages in Guatemala. Two of the villages received a protein-calorie preparation while the other two received a calorie supplement. Placental weight was higher among women with high levels of supplemented calories during pregnancy, independently of the type of food supplement ingested. On the average, the groups with low caloric supplementation (smaller than 20,000 calories) had placental weight 11 per cent below those with high caloric supplementation (larger than or equal to 20,000 calories), In contrast to placental weight, the concentration of placental chemical components studied was not associated with caloric supplementation. It was concluded that moderate protein-calorie malnutrition during pregnancy leads to lower placental weight without significantly changing the concentration of the biochemical components studied. The reduction of placental weight may be the mechanism by which maternal malnutrition is associated with high prevalence of low-birth-weight babies in these populations.

Differences in the epidemiology of prematurity and intrauterine growth retardation

Although both preterm (PT) and intrauterine growth retarded (IUGR) infants can have similar birth weights, they are known to show different neonatal and post-neonatal features. Newborns (n = 623) from the Guatemalan longitudinal study of nutritional supplementation during pregnancy were studied. There were 61 PT (less than or equal to 37 wk) and 173 IUGR (less than or equal to 10th percentile) infants. Simultaneous adjustment using the long-linear model showed that calorie and/or protein supplementation during pregnancy lowered the risk of PT (adjusted odd ratios (OR) = 0.52, 95%, CI = 0.40-0.77, and 0.43 CI = 0.36-0.59, respectively), but did not affect the incidence of IUGR. Low maternal head circumference and weight increased the risk of IUGR only (OR = 1.4, CI = 1.02-1.8 and 2.3 CI = 1.8-2.7, respectively). Male fetuses were at higher risk of both PT and IUGR. These data confirm the differential effect of maternal characteristics and nutritional supplementation during pregnancy on both PT and IUGR, and strongly suggest the need to include both gestational age and birth weight as outcome measures in epidemiological studies, thus avoiding the exclusive use of LBW (less than or equal to 2500 g).

Relationship of maternal and infant nutrition to infant growth.

A cohort of all infants born between January 1, 1969 and February 28, 1977 in four rural villages in Eastern Guatemala which were participating in a longitudinal project of nutrition and mental development was studied. As part of the study, prospective information on anthropometric measurements, morbidity, dietary intake and socioeconomic and cultural characteristics was collected. In addition, two types of food supplements were distributed: calorie and protein-calorie. Attendance at the feeding centers in each village and the amount of supplements consumed by children and pregnant and lactating mothers were recorded daily. We studied the effect of the supplements consumed by the mother during pregnancy and lactation and by the infant on trimestral infant weight and length changes during the first year of life. The data indicate that infant calorie supplementation before three months of age is significantly and negatively associated with infant growth; after three months of age, supplemental calories consumed by the infant are significantly and positively associated with infant weight and length gains. In addition, a small positive association was found between maternal caloric supplementation during lactation and infant growth during the first two trimesters of life, after controlling for potentially confounding factors for which data are available in this study.

Genetic-environmental interactions in physical growth.

Abstract. Variability in stature among young children is often ascribed to health and nutrition differences in malnourished populations and to genetic differences in well‐nourished populations. Hence, it was hypothesized that parent‐child correlations in malnourished Guatemalan populations would be markedly lower than those reported for European samples. Instead, it was found that parent‐child and sibling correlations were similar in both kinds of populations. The simplest interpretation of these results is that variability in stature among malnourished children is as much a reflection of genetic differences as in developed nations. However, explanations can also be advanced which would attribute the higher than expected correlations to the environment. For instance, it could be that socioeconomic and nutritional status is correlated across generations. In other words, parents who had relatively better conditions as children are more likely to provide a better environment for their children. Consequently, the relative contribution of genetics and environment to variability in height is still unsettled. Nonetheless, it appears that variability in body size in malnourished populations, regardless of the relative importance of its causes, is a useful indicator of health and nutrition.

A simple assessment of the risk of low birth weight to select women for nutritional intervention

There is growing evidence that the high prevalence of low-birth-weight (LBW) babies, a characteristic of many poor societies, can be significantly reduced through nutritional intervention programs. In order to increase the efficiency of these programs, pregnant women at risk of delivering LBW babies must be identified. Several risk scales have been extensively used in urban populations of developed countries. However, these indicators are of little use in poor communities, since most of them require expensive laboratory techniques, a long interview, at least two visits to a health center, and a precise estimation of gestational age. The present paper proposes several risk indicators of LBW, appropriate for use in areas with inadequate health resources. In a four-year longitudinal study of pregnant women from poor rural villages in Guatemala, mothers of LBW babies were found to be typically small in stature and head circumference. In addition, their houses tended to be of relatively poor quality. The proportion of LBW babies found among women at risk, as defined by these indicators, was significantly lower among women with similar characteristics receiving adequate food supplementation during pregnancy. Categories of high risk were based on maternal height, head circumference, and house quality. It is concluded that use of these categories will increase the efficiency of these programs without decreasing significantly their effectiveness.

Effect of Maternal Nutrition on Infant Mortality

High infant mortality is a major health problem in many countries of the world. In these countries the infant mortality rate (IMR) remains a major determinant of life expectancy at birth and the first year of life is the single most important risk period that a person has to face. Maternal malnutrition has been implicated as an important cause of the high IMR reported in many developing nations. The objective of this paper is to review the published data on the relationship between maternal nutrition and infant mortality.

NUTRITION AND LENGTH OF GESTATION

Abstract This paper examines whether a food supplementation program carried out in Guatemala affected the length of gestation (n=830 singleton births). Women who consumed more of a protein-energy or an energy supplement had significantly longer lengths of gestation. Regression slopes of energy on length of gestation were statistically significant and similar for both types of supplements, suggesting a role for energy but not for protein. The earlier calories were provided in pregnancy the greater their effect on gestation length. Women in the upper tercile of the distribution of energy intakes in the first trimester of pregnancy had a mean length of gestation 1.42 weeks longer than women in the lower tercile of the distribution. The percent of preterm deliveries (