An index for proportion of head size to body mass during infancy

Impact of Neonatal Body (Dis)Proportionality Determined by the Cephalization Index (CI) on Gross Motor Development in Children with Down Syndrome: A Prospective Cohort Study

Background: Children with Down syndrome (DS) lag behind typical children in the acquisition of developmental milestones, which could differ depending on body proportionality. We aimed to determine the difference in the acquisition of developmental milestones in children with DS with a disproportionate cephalization index (CI) compared to a proportionate CI. We created a motor development model that predicted milestone acquisition times. Methods: In this 20-year prospective cohort study, 47 children with DS aged 3 months to 5 years, followed up to 2020, were grouped according to the ratio of head circumference to birth weight (HC/BW) or CI into proportionate (CI < 1.1) and disproportionate (CI ≥ 1.1). We used a modified Munich Functional Developmental Diagnostic Scale that was assessed for reliability and content validity (Levene’s test and discriminant analysis) to determine 28 motor milestones. Linear regression was used to predict time to milestone acquisition, controlling for sex, maternal age, and birth weight. Results: Compared to proportionate CI, children with disproportionate CI were delayed in the milestone acquisition of a prone position by 2.81 months, standing before walking by 1.29 months, and a supine position by 1.61 months. Both groups required more time to reach standing after the acquisition of independent walking, but children with disproportionate CI reached those milestones later (4.50 vs. 4.09 months, p < 0.001). Conclusion: Children with disproportionate CI acquired milestones in a predictable order but slower than those with a proportionate CI. Our findings support the need to classify the degree of motor developmental delay in children with DS into unique functional groups rather than rely on clinicians’ arbitrary descriptions of the timing of developmental delays in children with DS.

The Challenge of Assessing Microcephaly in the Context of the Zika Virus Epidemic

The present article examines the impact of the current limitations of the microcephaly definition in the context of the Zika virus outbreak. It highlights its dependence on the method used for determining gestational age and other anthropometric parameters, and includes original results of prevalence of microcephaly in four countries from two different continents (Mozambique, Brazil, Guatemala and Colombia). Alternative definitions of microcephaly are proposed to allow the identification of true cases of microcephaly in a more accurate manner.

The phenotypic spectrum of congenital Zika syndrome

In October 2015, Zika virus (ZIKV) outbreak the Brazilian Ministry of Health (MoH). In response, the Brazilian Society of Medical Genetics established a task force (SBGM-ZETF) to study the phenotype of infants born with microcephaly due to ZIKV congenital infection and delineate the phenotypic spectrum of this newly recognized teratogen. This study was based on the clinical evaluation and neuroimaging of 83 infants born during the period from July, 2015 to March, 2016 and registered by the SBGM-ZETF. All 83 infants had significant findings on neuroimaging consistent with ZIKV congenital infection and 12 had confirmed ZIKV IgM in CSF. A recognizable phenotype of microcephaly, anomalies of the shape of skull and redundancy of the scalp consistent with the Fetal Brain Disruption Sequence (FBDS) was present in 70% of infants, but was most often subtle. In addition, features consistent with fetal immobility, ranging from dimples (30.1%), distal hand/finger contractures (20.5%), and feet malpositions (15.7%), to generalized arthrogryposis (9.6%), were present in these infants. Some cases had milder microcephaly or even a normal head circumference (HC), and other less distinctive findings. The detailed observation of the dysmorphic and neurologic features in these infants provides insight into the mechanisms and timings of the brain disruption and the sequence of developmental anomalies that may occur after prenatal infection by the ZIKV.

Decreased head circumference velocity as related to developmental deficit in infancy

We evaluated the significance of head circumference growth velocity as related to developmental deficits during infancy. Head circumferences, lengths, and developmental diagnoses were retrieved in a standard manner at ≥ 2 time points from 437 infants with developmental deficits, and 3909 normally developing infants. Infants' ages ranged from 1-24 months, with final diagnoses ascertained at age 24 months. Increased velocity during the first 2 months in typical infants was evident in the study group during the period 2-4 months. A differential head circumference growth velocity was observed, and infants diagnosed with motor delay presented decreased velocity between ages 2-4 months, compared with infants receiving other nonmotor developmental diagnoses. These differences remained after controlling for birth weight and length. No significant sex effect was evident. Infants with developmental deficits demonstrate delayed acceleration of head circumference velocity, compared with typical infants in the first 2 months. Infants with motor delay manifest decreased velocity, compared with infants presenting other developmental deficits. These differences may be related to delayed white matter maturation.

Head growth evaluation in early childhood, from the Japan Children's Study

BACKGROUND

Head circumference (HC) trajectories are held to reflect neurological development and the acquirement of intelligence. It is important to assess HC growth accurately because atypical HC growth is an indicator of various developmental disorders. HC growth is determined by both familial and physical factors but, hitherto, no one has considered both factors together. The aim of the present study was thus to investigate the relationship between HC, physical growth, and parental HC.

METHODS

The study group in the Japan Children's Study consisted of 192 healthy full-term Japanese children. HC (maximum occiptofrontal circumference), height and bodyweight were measured at the ages of 4, 9 and 18 months. Multiple regression analysis were conducted predicting the HC from the body measurements and mid-parental HC (defined as the average of standardized paternal and maternal HC).

RESULTS

Adjusted multiple R(2) were 0.336, 0.307 and 0.259, measured at the aforementioned three stages. Bodyweight and mid-parental HC predicted the HC on each occasion (P < 0.01). Bodyweight was more relevant than mid-parental HC.

CONCLUSIONS

HC growth is influenced by physical growth and parental HC; therefore, it is important to consider both physical and familial factors. A formula is herein proposed to assess HC using bodyweight and mid-parental HC.

Assessment of head size adjusted for height: an anthropometric tool for clinical use based on Argentinian data

BACKGROUND

Relative macrocephaly describes a large head in relation to stature, and this indicator could be helpful in depicting syndromes with large heads and short stature, providing the existence of some relationship between both measurements in normal children.

OBJECTIVE

The aims of this study were (1) to evaluate the existence of a relationship between head circumference (HC), height and weight, (2) to build an instrument for evaluating it and validate its clinical utility.

SUBJECTS AND METHODS

Relationship between HC, height and weight was explored in a national sample of 3571 healthy, well nourished boys and girls aged 0-5.99 years. Age-adjusted correlation coefficients calculated were: HC and height, 0.30; HC and weight, 0.37; and height and weight, 0.60. A growth standard of HC to height ratio was constructed using the LMS method with both sexes pooled, and selected centiles and SD scores of HC to height ratio for each age were estimated. Z-scores of HC for age, and HC to height ratio were calculated for 13 children with hypochondroplasia, and 90 with achondroplasia, both conditions associated with macrocephaly.

RESULTS

Only four children with hypochondroplasia had HC for age above 2.00 SD, whereas all of them showed SD scores above 2.00 when the HC to height ratio was evaluated. Results suggest that the prepared standard may be of clinical utility.

CONCLUSIONS

A new standard is proposed, capable of pinpointing children with relative macrocephaly.