Search PubMed⌕ Search

Biomedical subjects

R Martorell

Publications and source records attributed to R Martorell.

At least 127 records · Page 7Linked to original sources

The indentification and evaluation of measurement variability in the anthropometry of preschool children.

Measurement variability estimates for 18 different anthropometric dimensions were collected within the context of an ongoing longitudinal in vestigation of preschool Guatemalan children. Estimates of total measurement variance, intra-observer variance, and short-term intra-subject variance are presented for each variable. A simple procedure for the evaluation of measurement variance in cross-sectional and longitudinal investigations is described in which the total measurement variance is expressed as a percentage of the appropriate inter-subject variance. This statistic serves as an index of the relative reproducibility of anthropometric variables.

Anthropometry↗

Influence of maternal nutrition on birth weight.

This paper discusses some conditions necessary to detect an effect of maternal nutrition on birth weight and the relative contribution of calories and protein to such an effect. The expected dose- and time-response relationships for nutritional interventions aimed at the improvement of birth weight are also discussed. There appears to be a minimal level of nutrients which must be available in order to obtain adequate birth weight. However, above this minimum level, pregnant women can adapt themselves to a wide variety of food intake, both in quantity and quality, without affecting birth weight. The relative contribution of calories and protein to an increase in birth weight depends on the limiting nutrients of the home diet in the population under study. Other factors like physical activity, prevalence of disease and magnitude of the maternal nutritional stores before pregnancy are also important determinants of the relative contribution of calories and protein to birth weight. The anticipated input of a nutritional intervention on birth weight should range between 25 and 84 g of birth weight/10,000 kcal ingested during pregnancy. This estimate was computed from analyses based on four sources of published data: weight gain during pregnancy, prepregnant weight, fetomaternal body composition, and food intake during pregnancy. The expected reduction in proportion of low birth weight (LBW less than 2.5 kg) babies following a nutritional intervention will depend not only on the estimated range of fetal weight increase but also on the total amount of supplemented calories ingested during pregnancy as well as on the existent proportion of low birth weight babies prior to the intervention. The offspring of women who have low prepregnant weight, poor diet, low level of replacement of the home diet by the supplement, low physical activity during pregnancy and good health status will show larger increase in birth weight per unit of supplemented calories. Finally, nutritional interventions during pregnancy as opposed to earlier in the life of the mother, should have the higher impact on birth weight. In consequence, interventions as of pregnancy are recommended.

Adaptation, Physiological↗

Nutritional status and the timing of deciduous tooth eruption.

The number of deciduous teeth in a sample of rural Ladino Guatemalan children was counted every 3 months through 24 months of age, and at 6-month intervals from 24 to 36 months. Nutritional status at birth, whether expressed as full-term birth weight or as maternal caloric supplementation during pregnancy, influences the timing of deciduous tooth eruption. Furthermore, the timing of deciduous tooth eruption seems more closely associated with postnatal weight than with birth weight. Although indices of nutritional deficiencies are associated with retarded tooth eruption, the use of mean number of deciduous teeth erupted as an estimate of mean chronological age in populations living under conditions of mild-to-moderate malnutrition is relatively accurate because errors of age estimation based on mean values for the present sample only vary between 1 and 2 months.

Birth Weight↗

Head and chest circumferences in rural Guatemalan Ladino children, birth to seven years of age.

Growth patterns in head and chest circumferences are reported for a mixed-longitudinal sample of rural Guatemalan Ladino children from birth to 7 years of age. The sample is representative of a population with suboptimal nutrition. Both circumferences show similar rapid growth from birth through 9 months, after which chest circumference continues to increase more rapidly, while head circumference increases at a slower rate. Chest circumference provides nutritional information apparently not contained in length and weight. Compared to a sample of well-nourished children from Denver, the head circumferences of Guatemalan children are consistently smaller. Differences are relatively small at birth, are well established by 6 months, and become progressively greater through 24 months. After 2 years the mean smaller head circumference of the Guatemalan children also reflects stunted growth during the first 2 years of life. Similarly, among 5-year-old Guatemalan children of similar stature, head circumference at 5 years of age indicates which of these children were more stunted in stature at 2 years of age.

Age Factors↗

Effect of food supplementation during pregnancy on birthweight.

The high prevalence of low-birthweight (less than or equal to 2,500 gm) babies in many poor communities is a major public health problem. Studies in humans in situations of acute starvation suggest an effect of maternal nutrition on birthweight, but less clear results appear under situations of moderate maternal malnutrition. We studied the effects of food supplementation during pregnancy on birthweight in four rural villages of Guatemala, in which two types of supplements were distributed: protein-caloric and caloric. The caloric supplementation increased the total caloric intake during pregnancy. In both supplements, the amount of calories supplemented during pregnancy showed a consistent association with birthweight. In the combined sample the proportion of low-birthweight babies in the high-supplement group (G greater than or equal to 20,000 supplemented calories during pregnancy) was 9% compared with 19% in the low-supplement group (less than 20,000 supplemented calories during pregnancy). The relationship between caloric supplementation and birthweight (29 gm of birthweight per 10,000 supplemented calories) was basically unchanged after controlling for the maternal home diet, height, head circumference, parity, gestational age, duration of disease during pregnancy, socioeconomic status, and different rates of missing data. Moreover, a similar association was found in consecutive pregnancies of the same mother. We concluded that caloric supplementation during pregnancy produced the observed increase in birthweight.

Age Factors↗