Mortality Risk in US Neonatal Intensive Care Unit Infants by Birth Size Classifications Comparing Three Growth Curves

INTRODUCTION

Three widely referenced growth curves classify infant birth anthropometric measurements as small (SGA), appropriate (AGA), or large (LGA) for gestational age (GA) differently. We assessed how these differences in assignment affect the identification and prediction of neonatal intensive care unit (NICU) mortality risk in US preterm infants.

METHODS

Birth data of infants admitted to NICUs from the Pediatrix Clinical Data Warehouse (2013-2018) were analyzed. Birth weight, length, and head circumference of 46,724 singleton infants (24-32 weeks GA) were classified as SGA, AGA, or LGA using the Olsen, Fenton, and INTERGROWTH-21st curves. NICU mortality risk based on birth size classification was analyzed using unadjusted and adjusted logistic regression stratified by GA.

RESULTS

Odds of mortality were increased with SGA classification at all GAs, size measurements, and curve sets, compared with AGA infants. LGA classification for weight was associated with lower mortality risk at 24 weeks GA and higher risk at 30 weeks GA. Odds of mortality did not differ significantly across curve sets. Classification of size at birth alone had relatively low predictive ability to identify mortality risk, with unadjusted AUCs near 0.5 for all analyses.

CONCLUSION

There were no significant differences across curve sets in predicting mortality. Classification of size at birth is a relatively imprecise method to identify infants at risk for NICU mortality.

Validation of growth standards and growth references: A review of literature

The World Health Organization (WHO) growth standards provide the most recognized and widely accepted way of assessing child growth. To ensure its applicability, accuracy, and reliability, studies have validated WHO growth standards against local populations and other internationally recognized growth references. We reviewed outcomes of evaluations done on WHO growth standards and assess the appropriateness of using these growth standards on a global level. We undertook a systematic quantitative review of studies published from 2011 to 2020 from multiple databases. Studies were included if they considered children aged 59 months and below and reported on validation of growth standards. There was an agreement in studies that validated WHO growth standards against international growth references of its superiority in identifying stunted, overweight, and obese children. However, they were less likely to identify underweight children. None of the studies reviewed reported similar growth trajectories to WHO standards in all indicators considered. Regional differences in child growth were observed in comparison to WHO growth standards. Adoption of regional-specific standards increases the sensitivity of identifying children with adverse nutrition outcomes.

Is the World Health Organization’s multicentre child growth standard an appropriate growth reference for assessing optimal growth of South African mixed-ancestry children?

In South Africa (SA), it has been estimated that one-third of boys and 25% of girls under the age of 5 years are stunted, according to the World Health Organization (WHO) Multicentre Growth Reference Study. During the past decade, research in developed and developing countries has shown that the international growth standard overestimates stunting and/or wasting when compared with population-specific growth references. Population-specific growth references typically incorporate genetic and environmental factors and can therefore better inform public health by identifying children who may be at risk for malnutrition, or who may be ill. Using the universal growth standard in SA may not be accurately assessing growth. In this article, environmental and genetic factors, and their influence on growth, are reviewed. These points are illustrated through a brief history of the peopling of SA, with an understanding of the socioeconomic and political climate – past and present. We discuss the uniqueness of certain population groups in SA, with contributions regarding some of the shortest peoples in the world and a history of sociopolitical inequities, which may mean that children from certain population groups who are perfectly healthy would underperform using the universal growth standard. Therefore, we suggest that a local population-specific growth reference would serve to better inform public health policies, and address childhood health equity and physical developmental pathways to adult health risk status.  

Screening of hydrocephalus in infants using either WHO or population-based head circumference reference charts

AIM

The aim was to compare the performances of the World Health Organization (WHO) and population-based (PB) references in the screening for hydrocephalus in infants aged <2 years.

METHODS

We collected 341 longitudinal head circumference (HC) measurements of hydrocephalic infants and 120 181 measurements of 15 145 healthy infants from primary care. The measurements were converted into z-scores, and a new screening parameter, change in HC standard deviation score (SDS) over time (ΔHC SDS), was calculated. Comparisons were made using receiver operating characteristics analysis and linear mixed models.

RESULTS

The mean HC SDS_WHO was 3.5 and the mean HC SDS_PB was 2.9 in the hydrocephalic infants, and in healthy children, those numbers were 1.0 SDS_WHO and 0 SDS_PB , respectively. The best screening accuracy was obtained with the PB reference in combination with the ΔHC SDS parameter (AUC 0.89). The accuracy of the WHO standard could be improved to a similar level by customising the screening cut-offs of HC SDS according to the population and combining screening parameters.

CONCLUSIONS

Auxology alone was not sufficient for the screening of hydrocephalus. The WHO standard should be validated in the population, and population-specific cut-offs for normality defined before its introduction.

Differences between WHO Growth Standards and China Growth Standards in Assessing the Nutritional Status of Children Aged 0-36 Months Old

Background: At present, whether to use the World Health Organization’s (WHO) growth standards or native growth standards to assess the nutritional status in a given population is unclear. This study aimed to compare the differences between the WHO’s growth standards and China’s growth standards in assessing the nutritional status of children aged 0~36 months. Methods: We used z-scores to evaluate the nutritional status of children. The weight-for-age z-scores (WAZs), length/height-for-age z-scores (LAZ/HAZs), and weight-for-length/height z-scores (WLZ/WHZs) were calculated using the WHO’s growth standards and China’s growth standards. MeNemar’s test was used to compare the nutritional status of children. Results: The results in this study showed that there were differences between the WHO’s standards and China’s standards in assessing children’s nutritional status except for stunting and obesity. The prevalence of underweight assessed using China’s standards was higher than when using the WHO’s standards (except when 3 and 36 months old). The prevalence of wasting was significantly higher when assessed using China’s standards than when using the WHO’s standards from 12 to 36 months. The prevalence of overweight was higher when assessed using the WHO’s standards from 3 to 8 months. Conclusions: Both the WHO’s and China’s growth standards are useful measures in assessing children’s nutritional status but with key significant differences. Therefore, caution should be taken in selecting appropriate measures in a given population.

The Low Prevalence of Overweight and Obesity in Czech Breastfed Infants and Young Children: An Anthropological Survey

The aim of this study is to evaluate the prevalence of overweight and obesity in a sample of children who were exclusively or predominantly breastfed for at least 6 months compared to Czech references that were constructed based on a representative sample of children, regardless of their mode of feeding. Between 2008 and 2011, a longitudinal study on the growth of breastfed infants was carried out in the Czech Republic. Forty-three GP pediatricians addressed parents at 18-month preventive examinations and collected data on the families' socio-economic conditions and the infants' feeding conditions. The children were measured (length, weight, and head circumference), and anthropometric measurements from 10 previous preventive examinations were obtained from the health records. Out of the collected 1775 questionnaires, 960 children were selected according to the criteria of the WHO Multicentre Growth Reference Study. For the purpose of this study, 799 children who were exclusively or predominantly breastfed for at least 6 months were selected. We found that the proportions of children who were classified as overweight (>90th percentile) or obese (>97th percentile) at 6, 12, and 18-month examinations were far below the proportions of the Czech references. An update of the Czech references and growth charts is highly recommended by GP pediatricians for the valid assessment of growth and nutritional status, including a screening of overweight and obesity in primary preventive health care.

Body parameters of Czech breastfed children compared to the Czech references and WHO growth standards

BACKGROUND

The study concerns the comparison of percentile curves of Czech breastfed children with Czech national references from 1991 and 2001 and WHO growth standards. Growth charts of breastfed children demonstrate different curve shapes, especially in the first months of life. Incorrect interpretation of the growth curve could lead to premature introduction of complementary foods or infant formula.

AIM

The comparison of four body parameters of Czech breastfed children with currently used Czech national references and WHO standards in order to recommend that Czech paediatricians use either Czech references or WHO standards in their practice.

SUBJECTS AND METHODS

Nine hundred and sixty breastfed children were included in the study of length-for-age, head circumference-for-age, weight-for-age and weight-for-length parameters. All percentile curves were compared. Values of the 50th percentile expressed in z-scores based on both Czech references and WHO standards were tested.

RESULTS

The study confirmed results of previous surveys documenting that growth of breastfed children is specific. Nevertheless, percentile curves of growth parameters of Czech breastfed children are closer to Czech references than WHO standards.

CONCLUSIONS

The Czech national references fulfil the needs of Czech paediatricians (with pointing to specifics of breastfed child growth) and WHO standards are suitable, especially for international comparison.

The 5th national survey on the physical growth and development of children in the nine cities of China: Anthropometric measurements of Chinese children under 7 years in 2015

OBJECTIVES

To describe the physical growth of healthy children under 7 years in China based on the latest national survey and provide more data for revising growth reference and monitoring the impact of social development on children's health and growth.

METHODS

In the cross-sectional survey, 161,774 healthy children under 7 years were selected by multistage stratified cluster sampling method in nine cities of China. According to the geographical location, the nine cities were divided into northern, central and southern regions, and each city included urban and suburban areas. Anthropometric measurements were obtained on the spots and other related information was collected with questionnaires.

RESULTS

There were slight urban-suburban difference and obvious regional difference in anthropometric measurements in China. Comparison with the 4th NSPGDC in 2005, measurements increased 0.1-1.1 kg in weight, 0.5-1.8 cm in height in urban areas (except children under 3 years) and 0.1-2.5 kg in weight, 0.2-3.8 cm in height in suburban areas. The urban-suburban difference of those measurements became smaller than 10 years ago, but their regional difference persistently exist. Chinese children were 0.36 SD in weight, 0.43 SD in height in urban areas and 0.30 SD in weight, 0.30 SD in height in suburban areas higher than WHO standards.

CONCLUSIONS

Physical growth of children under 7 years old was undergoing a slowly positive secular trend during the latest decade in more economically developed regions of China. Urban-suburban difference of those measurements became smaller, while their regional difference persistently exist. Chinese healthy children under 7 years in nine cities was taller and heavier than WHO standards.

Growth monitoring as an early detection tool: a systematic review

Growth monitoring of apparently healthy children aims at early detection of serious underlying disorders. However, existing growth-monitoring practices are mainly based on suboptimal methods, which can result in delayed diagnosis of severe diseases and inappropriate referrals. We did a systematic review to address two key and interconnected questions underlying growth monitoring: which conditions should be targeted, and how should abnormal growth be defined? We systematically searched for studies reporting algorithms for growth monitoring in children and studies comparing the performance of new WHO growth charts with that of other growth charts. Among 1556 identified citations, 69 met the inclusion criteria. Six target conditions have mainly been studied: Turner syndrome, coeliac disease, cystic fibrosis, growth hormone deficiency, renal tubular acidosis, and small for gestational age with no catch-up after 2 or 3 years. Seven algorithms to define abnormal growth have been proposed in the past 20 years, but their level of validation is low, and their overall sensitivities and specificities vary substantially; however, the Grote and Saari clinical decision rules seem the most promising. Two studies reported that WHO growth charts had poorer performance compared with other existing growth charts for early detection of target conditions. Available data suggest a large gap between the widespread implementation of growth monitoring and its level of evidence or the clinical implications of early detection of serious disorders in children. Further investigations are needed to standardise the practice of growth monitoring, with a consensus on a few priority target conditions and with internationally validated clinical decision rules to define abnormal growth, including the selection of appropriate growth charts.