Algorithms to Define Abnormal Growth in Children: External Validation and Head-To-Head Comparison

Expected and Desirable Preterm and Small Infant Growth Patterns

Adequate nutrition is necessary for achieving optimal growth and neurodevelopment. Growth is a natural and expected process that happens concomitantly with rapid advancements in neurodevelopment. Serial weight, length, and head circumference growth measures are essential for monitoring development, although identifying pathological deviations from normal growth can pose challenges. Appropriate growth assessments require considerations that a range of sizes for length, head circumference, and weight are expected and appropriate. Because of genetic differences and morbidities, there is a considerable overlap between the growth of healthy infants and those with growth alterations. Parents tend to be over-concerned about children who plot low on growth charts and often need reassurance. Thus, the use of terms such as "poor" growth or growth "failure" are discouraged when growth is approximately parallel to growth chart curves even if their size is smaller than specific percentiles. No specific percentile should be set as a growth goal; individual variability should be expected. An infant's size at birth is important information that goes beyond the common use of prognostic predictions of appropriate compared with small or large for gestational age. The lower the birthweight, the lower the nutrient stores and the more important the need for nutrition support. Compared to term infants, preterm infants at term-equivalent age have a higher percentage of body fat, but this diminishes over the next months. Current research findings support expert recommendations that preterm infants should grow, after early postnatal weight loss, similar to the fetus and then term-born infants, which translates to growth approximately parallel to growth chart curves. There is no need for a trade-off between optimum cognition and optimum future health. Each high-risk infant needs individualized nutrition and growth assessments. This review aims to examine infant growth expectations and messaging for parents of preterm and term-born infants within the broader causal framework.

Comparison of WHO 2006 Growth Standards and Synthetic Indian References in Assessing Growth in Normal Children and Children with Growth-Related Disorders

Introduction

A good screening tool, such as a growth chart, should distinguish between children with normal growth and those with perturbed growth. Suitability of synthetic Indian growth references for diagnosing growth-related disorders for under-five children has not been evaluated. To assess the validity of World Health Organization (WHO) 2006 standards vs synthetic Indian references (2019) (by comparing weight, height, body mass index (BMI), standard deviation scores (SDS) and the composite index of anthropometric failure (CIAF)) in differentiating normal children and children with growth-related disorders.

Methods

Records of 2188 children (0-60 months) attending a tertiary centre paediatric outpatient department (OPD) were retrospectively studied; 1854 children were healthy and 334 were diagnosed with growth-related disorders as per the European Society for Paediatric Endocrinology (ESPE) classification. The anthropometric parameters converted to Z-scores for weight-for-age (WAZ), height-for-age (HAZ), BMI-for-age (BAZ) and a CIAF were computed using WHO and synthetic charts; Student's t-test was used for assessing differences and Youden's index for validity.

Results

Disease status of children and anthropometric failure on WAZ, HAZ, BAZ and CIAF on both WHO and synthetic charts had a significant association (P-value <0.05). WAZ, HAZ on both charts and CIAF on synthetic chart had a fair to moderate agreement (Kappa statistics) with disease status as per diagnosis (P-value <0.05). The sensitivity and negative predictive value for all anthropometric parameters were higher for synthetic charts.

Conclusion

Indian charts were more sensitive for diagnosing growth-related disorders from birth to 60 months of age when compared to WHO growth standards.

Age at diagnosis in patients with chronic congenital endocrine conditions: a regional cohort study from a reference center for rare diseases

BACKGROUND

For chronic congenital endocrine conditions, age at diagnosis is a key issue with implications for optimal management and psychological concerns. These conditions are associated with an increase in the risk of comorbid conditions, particularly as  it concerns growth, pubertal development and fertility potential. Clinical presentation and severity depend on the disorder and the patient's age, but diagnosis is often late.

OBJECTIVE

To evaluate age at diagnosis for the most frequent congenital endocrine diseases affecting growth and/or development.

PATIENTS AND METHODS

This observational cohort study included all patients (n = 4379) with well-defined chronic congenital endocrine diseases-non-acquired isolated growth hormone deficiency (IGHD), isolated congenital hypogonadotropic hypogonadism (ICHH), ectopic neurohypophysis (NH), Turner syndrome (TS), McCune-Albright syndrome (MAS), complete androgen insensitivity syndrome (CAIS) and gonadal dysgenesis (GD)-included in the database of a single multisite reference center for rare endocrine growth and developmental disorders, over a period of 14 years. Patients with congenital hypothyroidism and adrenal hyperplasia were excluded as they are generally identified during neonatal screening.

RESULTS

Median age at diagnosis depended on the disease: first year of life for GD, before the age of five years for ectopic NH and MAS, 8-10 years for IGHD, TS (11% diagnosed antenatally) and CAIS and 17.4 years for ICHH. One third of the patients were diagnosed before the age of five years. Diagnosis occurred in adulthood in 22% of cases for CAIS, 11.6% for TS, 8.8% for GD, 0.8% for ectopic NH, and 0.4% for IGHD. A male predominance (2/3) was observed for IGHD, ectopic NH, ICHH and GD.

CONCLUSION

The early recognition of growth/developmental failure during childhood is essential, to reduce time-to-diagnosis and improve outcomes.

Head circumference from birth to five years in France: New national reference charts and comparison to WHO standards

Background

The monitoring of head circumference (HC) is essential to early detect any conditions affecting its growth in early childhood. A positive secular trend and regional specificities in HC suggested the need to provide updated national HC reference growth charts.

Methods

We extracted all growth data collected from 42 primary-care physicians from across the French metropolitan territory who used the same electronic medical-records software. We selected HC measurements up to age five years for all children who were born after 1990 with birth weight > 2500 g. We derived new HC growth charts by using Generalized Additive Models for Location, Scale and Shape, then externally validated them until 30 months of age by comparison with the national population-based Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort and compared them to previous French and WHO growth charts.

Findings

With 973,869 HC measurements from 157,762 children, new calibrated HC growth charts from birth to age five years were generated. The new HC growth charts showed good external fit by comparison with the ELFE birth cohort. As compared with the new HC growth charts, the previous French and WHO growth charts mean HC z-scores were, respectively, -0.4 and -0.6 SD for girls and -0.2 and -0.6 SD for boys.

Interpretation

We produced and validated national calibrated HC growth charts by using a novel big-data approach applied to data routinely collected in clinical practice. Comparison with previous French and WHO growth charts confirmed a positive secular trend since the 1960s and regional specificities.

Funding

The French Ministry of Health; Laboratoires Guigoz—General Pediatrics section of the French Society of Pediatrics—Paediatric Epidemiological Research Group; the French Association of Ambulatory Pediatrics; and educational grant from the Regional Health Agency of Ile-de-France.

Diagnosing Growth Hormone Deficiency: Can a Combined Arginine and Clonidine Stimulation Test Replace 2 Separate Tests?

OBJECTIVE

Given the large number of false-positive growth hormone deficiency (GHD) diagnoses from a single growth hormone (GH) stimulation test in children, 2 different pharmacologic tests, performed on separate days or sequentially, are required. This study aimed to assess the reliability and safety of a combined arginine-clonidine stimulation test (CACST).

METHODS

This was a retrospective, single-center, observational study. During 2017-2019, 515 children aged >8 years underwent GH stimulation tests (CACST: n = 362 or clonidine stimulation test [CST]: n = 153). The main outcome measures used to compare the tests were GH response (sufficiency/deficiency) and amplitude and timing of peak GH and safety parameters.

RESULTS

Population characteristics were as follows: median age of 12.2 years (interquartile range [IQR]: 10.7, 13.4), 331 boys (64%), and 282 prepubertal children (54.8%). The GHD rate was comparable with 12.7% for CACST and 14.4% for CST followed by a confirmatory test (glucagon or arginine) (P = .609). Peak GH was higher and occurred later in response to CACST compared with CST (14.6 ng/mL [IQR: 10.6, 19.4] vs 11.4 ng/mL [IQR: 7.0, 15.8], respectively, P < .001; 90 minutes [IQR: 60, 90] vs 60 minutes [IQR: 60, 90], respectively, P < .001). No serious adverse events occurred following CACST.

CONCLUSION

Our findings demonstrate the reliability and safety of CACST in detecting GHD in late childhood and adolescence, suggesting that it may replace separate or sequential GH stimulation tests. By diminishing the need for the second GH stimulation test, CACST saves time, is more cost-effective, and reduces discomfort for children, caregivers, and medical staff.

Important Tools for Use by Pediatric Endocrinologists in the Assessment of Short Stature

Assessment and management of children with growth failure has improved greatly over recent years. However, there remains a strong potential for further improvements by using novel digital techniques. A panel of experts discussed developments in digitalization of a number of important tools used by pediatric endocrinologists at the third 360° European Meeting on Growth and Endocrine Disorders, funded by Merck KGaA, Germany, and this review is based on those discussions. It was reported that electronic monitoring and new algorithms have been devised that are providing more sensitive referral for short stature. In addition, computer programs have improved ways in which diagnoses are coded for use by various groups including healthcare providers and government health systems. Innovative cranial imaging techniques have been devised that are considered safer than using gadolinium contrast agents and are also more sensitive and accurate. Deep-learning neural networks are changing the way that bone age and bone health are assessed, which are more objective than standard methodologies. Models for prediction of growth response to growth hormone (GH) treatment are being improved by applying novel artificial intelligence methods that can identify non-linear and linear factors that relate to response, providing more accurate predictions. Determination and interpretation of insulin-like growth factor-1 (IGF-1) levels are becoming more standardized and consistent, for evaluation across different patient groups, and computer-learning models indicate that baseline IGF-1 standard deviation score is among the most important indicators of GH therapy response. While physicians involved in child growth and treatment of disorders resulting in growth failure need to be aware of, and keep abreast of, these latest developments, treatment decisions and management should continue to be based on clinical decisions. New digital technologies and advancements in the field should be aimed at improving clinical decisions, making greater standardization of assessment and facilitating patient-centered approaches.

Guideline for referring short or tall children in preventive child health care

AIM

To develop a guideline for preventive child healthcare professionals in order to improve early detection of pathological disorders associated with short stature (or growth faltering) or tall stature (or accelerated growth).

METHODS

We updated the previous Dutch guideline for short stature in children aged 0-9 years and extended it to adolescents (10-17 years), and added a guideline for tall stature, based on literature and input from an expert committee. Specificities were calculated in a cohort of healthy Dutch children aged 0-9 years (n = 970). We investigated the impact of a late onset of puberty on height standard deviation score based on the Dutch growth charts.

RESULTS

Growth parameters of the guideline include height, the distance between height and target height and change of height over time. Other parameters include diagnostic clues from medical history and physical examination, for example behavioural problems, precocious or delayed puberty, body disproportion and dysmorphic features.

CONCLUSION

Preventive child healthcare professionals now have an updated guideline for referring short or tall children to specialist care. Further research is needed on the diagnostic yield after referral and specificity at field level.

Early Detection of Abnormal Growth Associated with Juvenile Acquired Hypothyroidism

CONTEXT

Development of the typical growth phenotype in juvenile acquired hypothyroidism (JHT), the faltering linear growth with increasing weight, has not been thoroughly characterized.

OBJECTIVE

To describe longitudinal growth pattern in children developing JHT and investigate how their growth differs from the general population in systematic growth monitoring.

DESIGN

Retrospective case-control study.

SETTING

JHT cases from 3 Finnish University Hospitals and healthy matched controls from primary health care.

PATIENTS

A total of 109 JHT patients aged 1.2 to 15.6 years (born 1983-2010) with 554 height and weight measurements obtained for 5 years preceding JHT diagnosis. Each patient was paired with 100 healthy controls (born 1983-2008) by sex and age. Longitudinal growth pattern was evaluated in mixed linear models. Growth monitoring parameters were evaluated using receiver operating characteristics analysis.

RESULTS

At diagnosis, JHT patients were heavier (mean adjusted body mass index-for-age [BMISDS] difference, 0.65 [95% CI, 0.46-0.84]) and shorter (mean adjusted height-for-age deviation from the target height [THDEVSDS] difference, -0.34 [95% CI, -0.57 to -0.10]) than healthy controls. However, 5 years before diagnosis, patients were heavier (mean BMISDS difference, 0.33 [95% CI, 0.12-0.54]) and taller (mean THDEVSDS difference, 0.29 [95% CI, 0.06-0.52]) than controls. JHT could be detected with good accuracy when several growth parameters were used simultaneously in screening (area under the curve, 0.83 [95% CI, 0.78-0.89]).

CONCLUSIONS

Abnormal growth pattern of patients with JHT evolves years before diagnosis. Systematic growth monitoring would detect abnormal growth at an early phase of JHT and facilitate timely diagnosis of JHT.

Towards a Rational and Efficient Diagnostic Approach in Children Referred for Growth Failure to the General Paediatrician

Based on a recent Dutch national guideline, we propose a structured stepwise diagnostic approach for children with growth failure (short stature and/or growth faltering), aiming at high sensitivity for pathologic causes at acceptable specificity. The first step is a detailed clinical assessment, aiming at obtaining relevant clinical clues from the medical history (including family history), physical examination (emphasising head circumference, body proportions and dysmorphic features) and assessment of the growth curve. The second step consists of screening: a radiograph of the hand and wrist (for bone age and assessment of anatomical abnormalities suggestive for a skeletal dysplasia) and laboratory tests aiming at detecting disorders that can present as isolated short stature (anaemia, growth hormone deficiency, hypothyroidism, coeliac disease, renal failure, metabolic bone diseases, renal tubular acidosis, inflammatory bowel disease, Turner syndrome [TS]). We advise molecular array analysis rather than conventional karyotyping for short girls because this detects not only TS but also copy number variants and uniparental isodisomy, increasing diagnostic yield at a lower cost. Third, in case of diagnostic clues for primary growth disorders, further specific testing for candidate genes or a hypothesis-free approach is indicated; suspicion of a secondary growth disorder warrants adequate further targeted testing.

A big-data approach to producing descriptive anthropometric references: a feasibility and validation study of paediatric growth charts

BACKGROUND

Both national and WHO growth charts have been found to be poorly calibrated with the physical growth of children in many countries. We aimed to generate new national growth charts for French children in the context of huge datasets of physical growth measurements routinely collected by office-based health practitioners.

METHODS

We recruited 32 randomly sampled primary care paediatricians and ten volunteer general practitioners from across the French metropolitan territory who used the same electronic medical records software, from which we extracted all physical growth data for the paediatric patients, with anonymisation. We included measurements from all children born from Jan 1, 1990, and aged 1 month to 18 years by Feb 8, 2018, with birthweight greater than 2500 g, to which an automated process of data cleaning developed to detect and delete measurement or transcription errors was applied. Growth charts for weight and height were derived by using generalised additive models for location, scale, and shape with the Box-Cox power exponential distribution. We compared the new charts to WHO growth charts and existing French national growth charts, and validated our charts using growth data from recent national cross-sectional surveys.

FINDINGS

After data cleaning, we included 1 458 468 height and 1 690 340 weight measurements from 238 102 children. When compared with the existing French national and WHO growth charts, all height SD and weight percentile curves for the new growth charts were distinctly above those for the existing French national growth charts, as early as age 1 month, with an average difference of -0·75 SD for height and -0·50 SD for weight for both sexes. Comparison with national cross-sectional surveys showed satisfactory calibration, with generally good fit for children aged 5-6 years and 10-11 years in height and weight and small differences at age 14-15 years.

INTERPRETATION

We successfully produced calibrated paediatric growth charts by using a novel big-data approach applied to data routinely collected in clinical practice that could be used in many fields other than anthropometry.

FUNDING

The French Ministry of Health; Laboratoires Guigoz-General Pediatrics section of the French Society of Pediatrics-Pediatric Epidemiological Research Group; and the French Association for Ambulatory Pediatrics.