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The current international growth reference, the National Center for Health Statistics (NCHS) reference, is widely used to compare the nutritional status of populations and to assess the growth of individual children throughout the world. Recently, concerns were raised regarding the adequacy of this reference for assessing the growth of breast-fed infants. We used the NCHS reference to evaluate infant growth in one of the most developed areas of Brazil. Infants who were exclusively or predominantly breast-fed for the first 4-6 mo, and partially breast-fed thereafter, grew more rapidly than the NCHS reference in weight and length during the first 3 mo, but appeared to falter thereafter. The average growth of all infants, regardless of feeding pattern, was faster than the NCHS reference until approximately 6 mo, after which their growth became slower than that of the NCHS sample. To substantiate this finding, the NCHS growth curves were then compared with growth data of breast-fed infants in developed countries from pooled published studies, formula-fed North American and European infants and predominantly bottle-fed U.S. infants monitored by the Centers for Disease Control and Prevention (CDC) Pediatric Surveillance System. In all three cases, weights showed the same pattern as the Brazilian infants-higher than NCHS in the early months but an apparent decline thereafter. The pattern for length gain was similar but less marked. Breast-fed infants showed more pronounced declines than those who were predominantly bottle-fed. These findings suggest that the infancy portion of the NCHS reference does not adequately reflect the growth of either breast-fed or artificially fed infants. This probably results from characteristics of the original sample and from inadequate curve-fitting procedures. The development of an improved international growth reference that reflects the normal infant growth pattern is indicated.

PIP: The National Center for Health Statistics (NCHS) reference is the international standard widely used to compare the nutritional status of populations and to assess the growth of individual children around the world. There has, however, recently been concern over the adequacy of this reference for assessing the growth of breast-fed infants. Findings are presented from an evaluation of infant growth using the NCHS reference in the city of Pelotas, Brazil, one of the most developed areas of the country. The 5304 children enrolled in the study comprised all but 0.3% of all hospital births occurring in the city in 1993. Infants who were either exclusively or mainly breast-fed for the first 4-6 months, and partially breast-fed thereafter, grew faster than the NCHS reference in weight and length during the first 3 months, but appeared to falter thereafter. The average growth of all infants, regardless of feeding pattern, was faster than the NCHS reference until approximately age 6 months, after which they grew slower than did the NCHS sample. A comparison of NCHS growth curves with growth data on breast-fed infants in developed countries from pooled published studies, formula-fed North American and European infants, and mainly bottle-fed US infants monitored by the Centers for Disease Control and Prevention (CDC) Pediatric Surveillance System found infant weights in all cases to exhibit the same pattern as that of the Brazilian infants. The pattern for length gain was similar, but less marked. Breast-fed infants showed more pronounced declines than those who were mainly bottle-fed. An improved international growth reference should be developed and used.

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INTRODUCTION: Anthropometry is frequently used for evaluating nutritional status of individuals and populations. In recent years, community surveys have been conducted by health professionals in various regions of Brazil with the objective of complementing the data obtained through nutritional surveillance programs. One important difficulty in conducting these assessments has been measuring height during visits to the homes of survey participants. METHODS: Thirty-eight anthropometric surveys of Brazilian children aged up to 5 years using the National Center for Health Statistics (NCHS) reference were identified. The percentage of children with a Z-score below standard deviations was used to define deficits of weight for age and height for age. RESULTS: Correlation between prevalences of height for age and weight for age deficits were examined. Due to the low prevalence of deficits in weight for height in all surveys, there was a strong correlation between weight for age and height for age at the population level. Approximately 90% of the height for age (H/A) variation was accounted for by that of weight for age (W/A). CONCLUSIONS: Using the equation, (Prevalence H/A) = 0.74 + 2.34 (Prevalence W/A) -0.03 (Prevalence W/A)2 it is possible to estimate the prevalence of height deficits on the basis of prevalence of weight deficits. These results suggest that anthropometric surveys as conducted in Brazil, in the context of health services, can be simplified by measuring weight only, instead of both weight and height.

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The effect on birth outcome of work requiring different degrees of physical exertion was examined among 15,786 pregnant women who were followed through the Guatemalan Social Security Institute's hospital. Work inside and outside the home was ascertained through a questionnaire administered to each women before delivery. Odds ratios were adjusted for household income, maternal height and age, and birthweight of previous infant. Women with three or more children and no household help were at increased risk for small-for-gestational-age (SGA) births compared with women with family (odds ratio (OR) 1.79; 95% confidence interval (CI) 1.31, 2.47) or hired help (OR 2.0; 95% CI 1.16 to 3.33). Compared with office work, manual work increased the risk for an SGA (OR 1.32; 95% CI 1.12 to 1.56) and SGA/preterm birth (OR 2.56; 95% CI 1.10 to 5.96). Work in a standing compared with sitting position significantly increased the risk for a preterm birth (OR 1.56; 95% CI 1.04 to 2.60). There was a significant positive trend in frequency of SGA and SGA/preterm birth with an increase in the physical demands at work, as measured by an activity score. These data suggest that interventions to reduce physical exertion among pregnant women could improve birth outcome.

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