Parental childhood growth and offspring birthweight: pooled analyses from four birth cohorts in low and middle income countries.

OBJECTIVE: Associations between parental and offspring size at birth are well established, but the relative importance of parental growth at different ages as predictors of offspring birthweight is less certain. Here we model parental birthweight and postnatal conditional growth in specific age periods as predictors of offspring birthweight. METHODS: We analyzed data from 3,392 adults participating in four prospective birth cohorts and 5,506 of their offspring. RESULTS: There was no significant heterogeneity by study site or offspring sex. 1SD increase in maternal birthweight was associated with offspring birthweight increases of 102 g, 1SD in maternal length growth 0-2 year with 46 g, and 1SD in maternal height growth Mid-childhood (MC)-adulthood with 27 g. Maternal relative weight measures were associated with 24 g offspring birth weight increases (2 year- MC) and 49 g for MC-adulthood period but not with earlier relative weight 0-2 year. For fathers, birthweight, and linear/length growth from 0-2 year were associated with increases of 57 and 56 g in offspring birthweight, respectively but not thereafter. CONCLUSIONS: Maternal and paternal birthweight and growth from birth to 2 year each predict offspring birthweight. Maternal growth from MC-adulthood, relative weight from 2-MC and MC-adulthood also predict offspring birthweight. These findings suggest that shared genes and/or adequate nutrition during early life for both parents may confer benefits to the next generation, and highlight the importance of maternal height and weight prior to conception. The stronger matrilineal than patrilineal relationships with offspring birth weight are consistent with the hypothesis that improving the early growth conditions of young females can improve birth outcomes in the next generation.

Differential influences of early growth and social factors on young children's cognitive performance in four low-and-middle-income birth cohorts (Brazil, Guatemala, Philippines, and South Africa).

BACKGROUND: Studies relating childhood cognitive development to poor linear growth seldom take adequate account of social conditions related to both, leading to a focus on nutrition interventions. We aimed to assess the roles of both biological and social conditions in determining early childhood cognition, mediated by birthweight and early linear growth. METHODS: After exploratory structural equation modelling to identify determining factors, we tested direct and indirect paths to cognitive performance through birthweight and child height-for-age at 2 years, assessed between 4 and 8.5 years of age among 2448 children in four birth cohort studies in low-and-middle-income countries (Brazil, Guatemala, Philippines and South Africa). Determinants were compared across the cohorts. FINDINGS: Three factors yielded excellent fit, comprising birth endowment (primarily maternal age and birth order), household resources (crowding, dependency) and parental capacity (parental education). We estimated their strength together with maternal height in determining cognitive performance. Percentage shares of total effects of the four determinants show a marked transition from mainly biological determinants of birth weight (birth endowment 34%) and maternal height (30%) compared to household resources (25%) and parental capacity (11%), through largely economic determinants of height at 2 years (household resources (60%) to cognitive performance being predominantly determined by parental capacity (64%) followed by household resources (29%). The largely biological factor, birth endowment (maternal age and birth order) contributed only 7% to childhood cognitive performance and maternal height was insignificant. In summary, the combined share of social total effects (household resources and parental capacity) rises from 36∙2% on birth weight, to 78∙2% on height for age at 24 m, and 93∙4% on cognitive functioning. INTERPRETATION: Across four low- and middle-income contexts, cognition in childhood is influenced more by the parental capacity of families and their economic resources than by birth weight and early linear growth. Improving children's cognitive functioning requires multi-sectoral interventions to improve parental education and enhance their economic wellbeing, interventions that are known to improve also early childhood growth.

Size at birth, infant, early and later childhood growth and adult body composition: a prospective study in a stunted population.

BACKGROUND: Pre-natal and post-natal growth are associated with adult body composition, but the relative importance of growth in different periods of childhood is still unclear, particularly in stunted populations. METHODS: We studied 358 women and 352 men measured as children in 1969-77 in four villages in Guatemala, and re-measured as adults in 2002-04 (mean age 32.7 years). We determined the associations of body mass index (BMI) and length at birth, and changes in BMI and length during infancy (0-1.0 year) and early (1.0-3.0 years) and later (3.0-7.0 years) childhood, with adult BMI ((a)BMI), percentage of body fat ((a)PBF), abdominal circumference ((a)AC) and fat-free mass ((a)FFM). RESULTS: Prevalence of stunting was high (64% at 3 years; HAZ < -2SD). Obesity (WHZ > 2SD) prevalence in childhood was <2%, while overweight prevalence in adulthood was 52%. BMI at birth was positively associated with (a)BMI and (a)FFM while length at birth was positively associated with (a)AC and (a)FFM. Increased BMI in infancy and later childhood were positively associated with all four adult body composition measures; associations in later childhood with fatness and abdominal fatness were stronger than those with (a)FFM. Change in length during infancy and early childhood was positively associated with all four adult body composition outcomes; the associations with (a)FFM were stronger than those with fat mass. CONCLUSIONS: Increases in BMI between 3.0 and 7.0 years had stronger associations with adult fat mass and abdominal fat than with (a)FFM; increases in length prior to age 3.0 years were most strongly associated with increases in (a)FFM.

Multicausal etiology of anemia among women of reproductive age in Vietnam.

BACKGROUND/OBJECTIVES: Anemia is a significant public health concern, especially among women and young children. An improved understanding of the complex etiology of anemia is crucial for developing appropriate prevention strategies. This paper examines the determinants of anemia in a large sample of Vietnamese women of reproductive age (WRA). METHODS: We included baseline data from 4986 WRA participating in a randomized controlled trial (PRECONCEPT). Hemoglobin (Hb) concentrations were measured with Hemocue. Plasma ferritin (Fe), retinol binding protein (RBP) and markers of inflammation were assessed using the ELISA technique. We used multivariate logistic regression to describe associations with anemia and structural equation modeling (SEM) to characterize direct and indirect pathways influencing Hb concentrations. RESULTS: Prevalence of anemia, iron deficiency (Fe <12 µg/l), insufficient iron stores (Fe<30 µg/l) and iron deficiency anemia was 19.7, 3.5, 14.4 and 1.9%, respectively. Ferritin concentration (0.29 per log-mg/dl), being an ethnic minority (-0.24 compared with Kinh), number of children (-0.17) and socioeconomic status (0.09) were directly associated with Hb concentration (P<0.05). Similarly, RBP was directly (0.27 per mg/dl) associated with Hb and also indirectly (0.09 mg/dl) with ferritin. Hookworm infection was indirectly associated with Hb (-0.11) through RBP and ferritin. CONCLUSION: These findings illustrate the complex etiology of anemia and provide a useful framework for designing, targeting and evaluating appropriate strategies for the prevention and control of anemia. Contrary to expectations, iron deficiency accounted for a very small proportion of anemia in Northern Vietnam.

Maternal and fetal responses to the stresses of lactation concurrent with pregnancy and of short recuperative intervals.

In many regions of the world, women breastfeed one child while pregnant with the next. Among rural Guatemalan women participating in a nutrition-supplementation trial, lactation overlapped with pregnancy in 253 of 504 (50.2%) of the pregnancies. For cases where overlap occurred, 41.4% continued to breast-feed into the second trimester and 3.2%, in the third trimester. The maternal and fetal responses to the energetic stresses of overlap and of the duration of the recuperative (nonpregnant, nonlactating) interval were assessed. Overlap resulted in increased supplement intake. Short recuperative periods (less than 6 mo) resulted in increased supplement intake and reduced maternal fat stores. The energetic stresses of overlap and short recuperative periods did not significantly affect fetal growth. The mother appears to buffer the energetic stress, protecting fetal growth. This research demonstrates that evidence of depletion of maternal nutrient stores caused by a demanding reproductive history is found when reproductive stress is characterized adequately.

Incidence and duration of breast-feeding in Mexican-American infants, 1970-1982.

The Mexican-American component of the Hispanic Health and Nutrition Examination Survey (HHANES-MA) was used to examine the breast-feeding behavior of 2402 infants born between 1970 and 1982. The proportion of infants ever breast-fed increased substantially in recent years. Weighted proportions were 30.7% for 1970-1974, 38.1% for 1975-1978, and 47.6% for 1979-1982. By use of logistic regression models, children born into households with a college-educated head were shown to be more likely to be breast-fed than were other children; breast-feeding was also positively associated with birth weight. Infants in households for which the preferred interview language was Spanish were more likely to be breast-fed than were infants living in households for which the interview was conducted in English. Analysis of the factors influencing the distribution of weaning times among infants was less definitive because reported weaning times are heaped on multiples of 3 mo. The gathering of current-status, or status quo, information on infant feeding is urged for data collection in future studies.

Prevalence of overweight and obesity in US Hispanic populations.

Previous studies showed that Hispanics have higher levels of overweight and obesity than do US whites. The Hispanic Health and Nutritional Examination Survey (1982-1984) provides the basis for examining the physical characteristics of this population on a wider scale than previously possible. Data for body mass index (BMI; weight/height2) and triceps and subscapular skinfold thicknesses were examined for the 7052 Mexican Americans, 1307 Cubans, and 2690 Puerto Ricans for whom each of these measurements were available. Prevalence of obesity and overweight was defined as BMI in excess of the 95th and 85th percentiles, respectively, of US reference standards. In male adults prevalence values were, respectively, 10.6% and 33.5% for Mexican Americans, 9.6% and 31.3% for Puerto Ricans, and 9.0% and 34.0% for Cubans. In female adults prevalence values were, respectively, 15.1% and 42.3% for Mexican Americans, 7.8% and 40.7% for Puerto Ricans, and 15.0% and 38.2% for Cubans. Skinfold-thickness data for these populations indicate a centralized distribution of adipose tissue, especially in males, and increased subscapular skinfold thicknesses in older women.

Characteristics and determinants of child nutritional status in Nepal.

Herein, we examine characteristics and determinants of child malnutrition in the districts of Bara and Rautahat of the Terai region of Nepal. The sample studied consists of 510 rural children ranging in age from 3 to 10 yr. The Nepali children were found to have one of the highest reported prevalences of stunting (65% were less than 90% National study for Health Statistics median height for age). The study children were also 1 to 1.5 kg lighter when compared to US children of the same height. Fat deposits, as measured by anthropometric variables and Hb levels were also very low. Multiple regression analysis showed that age, district of residence, household income, breast-feeding, and several specific food items were significant predictors of nutritional status. Association with other factors such as caste and parental schooling, were not evident in multiple regressions. Boys were as likely to be malnourished as girls. Prolonged breast-feeding was associated with greater fat stores, but with reduced stature and low Hb values. Both landholdings and household income were found to be positively and significantly associated with almost all measures of nutritional status.

PIP: This paper examines the characteristics and determinants of child malnutrition in the districts of Bara and Rautahat of the Teriae region of Nepal. The sample studied consists of 510 rural children ranging in age from 3 to 10 years. The Nepali children were found to have 1 of the highest reported prevalences of stunting (65% were 90% National study for Health Statistics median height for age). The study children were also 1 to 1.5 kg lighter when compared to US children of the same height. Fat deposits, as measured by anthropometric variables and Hb levels were very low. Multiple regression analysis showed that age, district of residence, household income, breastfeeding, and several specific food items were significant predictors of nutritional status. Association with other factors such as caste and parental schooling, were not evident in the analysis. Boys were as likely to be malnourished as girls. Prolonged breastfeeding was associated with greater fat stores, but with reduced stature and low Hb values. Both landholdings and household income were found to be positively and significantly associated with almost all measures of nutritional status.

Nutrition, lactation, and birth interval components in rural Guatemala.

The effects of maternal nutritional status and food supplementation ingested by the infant on the duration of postpartum amenorrhea and on the duration of the menstruating interval was examined. A significant negative association was found between the nutritional status of the mother during the 3rd trimester of pregnancy and infant supplementation, on the one hand, and the length of postpartum amenorrhea on the other hand. These associations remained significant after controlling for each other and for other potentially confounding factors for which data wee collected. These results support the hypothesis that maternal nutritional status, by determining the amount of breast milk available, hence the frequency, duration, and intensity of suckling, is indirectly, negatively associated to the length of postpartum amenorrhea. Furthermore, no association between maternal nutritional status and the length of the menstruating interval was found.

Consequences for maternal nutrition of reproductive stress across consecutive pregnancies.

Frequent cycles of reproduction increase the risk that lactation will overlap with pregnancy and shorten the duration of the recuperative interval (nonpregnant and nonlactating portion) within the reproductive cycle, thereby increasing the risk of maternal nutritional depletion. Nutritional responses to these stresses have been demonstrated by contrasting groups of women with different experiences; however, these relationships may be spurious and the result of third factors. In this study, responses to changing stress over consecutive pregnancies were studied and contrasted within individual Guatemalan women; biases caused by factors constant to women were eliminated. Stress was assessed by examining responses in maternal supplement intake, maternal fat stores, and birth weight. Overlap and short recuperative intervals were found to be stressful (in that order) for mothers as shown by increased supplement intake and reduced fat stores. Birth weight in term gestations was not affected, indicating that fetal growth is being protected at the cost of maternal nutritional status.

Screening for nutrition interventions: the risk or the differential-benefit approach?

The risk approach has been promoted to improve screening for nutrition interventions on the premise that indicators of risk also predict greater response to interventions. This study tested whether the determinants of the risk of poor growth (eg, low length-for-age) at 36 mo of age were the same as the determinants of differential benefit from food supplementation. The sample included 460 Guatemalan children who were exposed to either a high-energy, high-protein drink (atole) or a low-energy, no-protein drink (fresco) during their first 36 mo of life [INCAP (Institute of Nutrition of Central America and Panama) supplementation trial]. Low maternal stature, poor socioeconomic status, inadequate home diet, high diarrhea rates, and low anthropometry scores at 3 or 6 mo were all determinants of the risk of poor growth. Only indicators of child's thinness at 3 or 6 mo of age (low weight-for-age, weight-for-length, or midupper arm circumference) were determinants of differential benefit from supplementation. Thus, the development of screening indicators should be based on analyses of the predictors of differential benefit, not on conventional risk-factor analysis.

The impact of ordinary illnesses on the dietary intakes of malnourished children.

The effect of respiratory infections, diarrhea, illness-induced apathy, and of a summary variable of selected common symptoms on food intake was estimated from data collected on preschool children from rural Guatemala. The presence of selected common symptoms was associated with an average reduction in daily intake of nearly 20%, equivalent to 175 kcal and 4.8 g of protein. Effects were of similar magnitude for diarrhea and for apathy but lower for respiratory infections, namely 61 kcal and 1.0 g of protein. It is concluded that common illnesses are an important cause of low dietary intakes in children from Guatemama.

Upper arm anthropometric indicators of nutritional status.

The growth in arm muscle area and arm fat area of preschool children from rural Guatemala is compared to that of a standard from the U.S.A. It was found that although the Guatemalan children have reduced arm muscle and fat areas, the relative reduction in arm fat area was greater than in arm muscle area. Further, the upper arm cross-sectional area of Guatemalan children had proportionately more muscle than fat when compared to that of U.S.A. children. Lastly, for the same body weight, Guatemalan children had a similar arm muscle area but a clearly smaller arm fat area than North American children. It is concluded that these findings suggest that energy rather than protein is the main nutritional problem in these Guatemalan children.

Predicting body composition from anthropometry and bioimpedance in marginally undernourished adolescents and young adults.

Body-composition prediction equations were developed using data from a sample of 201 female and male Guatemalan ladinos (ie, people of Amerindian-European descent) aged 11-25 y. Fat-free mass (FFM) values were estimated from body density by using the two-component model and age- and sex-specific values for the density of FFM. The root-mean-square error (RMSE) of the best model predicting FFM from a set of simple anthropometric variables was 1.59 kg for females and 1.90 kg for males. The addition of more extensive anthropometry to the set of candidate predictors reduced the RMSE to 1.42 kg for females and 1.88 kg for males. The subsequent addition of a bioelectrical impedance measure (Ht2/R) further reduced the RMSE to 1.32 kg for females and 1.82 kg for males. These results suggest that for a marginally undernourished population with relatively little body fat, simple anthropometrics are as useful as more sophisticated measures for the prediction of body composition.

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.

PIP: This paper discusses some conditions necessary to detect an effect of maternal nutrition on birthweight 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 birthweight are also discussed. There appears to be a minimal level of nutrients which must be available in order to obtain adequate birthweight. However, above this minimum level, pregnant women can adapt themselves to a wide variety of food intake, both in quantity and quality, without affecting birthweight. The relative contribution of calories and protein to an increase in birthweight depends on 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 prior to pregnancy are also important determinants of the relative contribution of calories and protein to birthweight. The anticipated input of a nutritional intervention on birthweight should range between 25-84 g of birthweight/10,000 kcal ingested during pregnancy. This estimate was computed from analyses based on 4 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 birthweight (LBW or= 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 birthweight babies prior to the intervention. The offspring of women who have low prepregnant weight, poor diet, low level of replacement of home diet by the supplement, low physical activity during pregnancy, and good health status will show larger increase in birthweight/unit of supplemented calories. Finally, nutritional interventions during pregnancy as opposed to earlier in the life of the mother, should have the highest impact on birthweight. Consequently, interventions as of pregnancy are recommended.

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.

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.

Therapeutic effects of oral zinc in acute and persistent diarrhea in children in developing countries: pooled analysis of randomized controlled trials.

BACKGROUND: Zinc deficiency is prevalent in children in developing countries. Supplemental zinc provides therapeutic benefits in diarrhea. OBJECTIVE: We sought to measure the effect of supplemental zinc given with oral rehydration therapy during recovery from acute or persistent diarrhea. DESIGN: We conducted pooled analyses including all available published and unpublished randomized controlled trials of the effects of supplementary oral zinc in children aged <5 y with acute or persistent diarrhea. We used Cox survival regression analysis to evaluate the overall effect of zinc on continuation of diarrhea and possible differential effects in subgroups divided by sex, age, weight-for-height, and initial plasma zinc concentration. Dichotomous outcomes were analyzed by logistic regression. To assess the effects of excluding studies without original data from the pooled analyses, effect-size was estimated for all studies by using random-effects models. RESULTS: Zinc-supplemented children had a 15% lower probability of continuing diarrhea on a given day (95% CI: 5%, 24%) in the acute-diarrhea trials and a 24% lower probability of continuing diarrhea (95% CI: 9%, 37%) and a 42% lower rate of treatment failure or death (95% CI: 10%, 63%) in the persistent-diarrhea trials. In none of the subgroup analyses were the 2 subgroups of each pair significantly different from each other; however, in persistent diarrhea there tended to be a greater effect in subjects aged <12 mo, who were male, or who had wasting or lower baseline plasma zinc concentrations. CONCLUSION: Zinc supplementation reduces the duration and severity of acute and persistent diarrhea.

Genetic and environmental determinants of growth in Mexican-Americans.

Height and weight data from the Mexican-American portion of the Hispanic Health and Nutrition Examination Survey (HHANES) are shown for children of ages 2 to 17 years and compared with data for non-Hispanic white children from the second National Health and Nutrition Examination Survey and with the National Center for Health Statistics (NCHS) reference curves. Differences in stature between the Hispanic Health and Nutrition Examination Survey and the reference populations were minor prior to adolescence and could be entirely attributed to the greater poverty of Mexican-Americans. However, differences increased during adolescence (ie, median stature was less than the 25th percentile of the NCHS reference population at 17 years of age) and, in contrast with earlier ages, were independent of poverty. Similar growth patterns were observed in samples of upper-class subjects from Mexico and Guatemala. Nonetheless, the extent to which the short stature of Mexican-American adolescents is genetic is unclear because there is an apparent time trend toward greater stature in the Mexican-American population. In conclusion, the NCHS reference curves are appropriate growth standards for preadolescent Mexican-American children. Whether they are valid for Mexican-American adolescents remains unclear.

Heterogeneous growth and mental development of intrauterine growth-retarded infants during the first 3 years of life.

Postnatal growth and development were studied in two groups of term infants with intrauterine growth retardation (IUGR) and one group of infants with normal birth weight up to 3 years of age (total sample, 205 infants). Infants with IUGR were classified as having low ponderal index (IUGR-LPI) or adequate ponderal index (IUGR-API). At birth, the two groups of infants with IUGR had similar birth weight, but length and head circumference measurements were significantly different. Overall, the IUGR-API infants remained lighter and shorter and had smaller head circumferences up to 30 months of age. The IUGR-LPI infants experienced catch-up growth in weight during the first months, because of greater fat deposition. At 24 months of age, the IUGR-API infants scored below the others on mental items. At 3 years of age the IUGR-API infants had the lowest values on seven of eight developmental measures and on the composite score; at these two time periods, the group with normal birth weight scored the highest, and the IUGR-LPI infants obtained intermediate values. It is concluded that infants with IUGR tend to follow postnatal growth and developmental patterns that are associated with their physical characteristics at birth.