A review of environmental contributions to childhood motor skills

Infants of mothers with early remitted clinical depression and mothers with no postpartum depression: Adaptive functioning in the second year of life

Whether and how remitted clinical depression in postpartum motherhood contributes to poor infant adaptive functioning is inconclusive. The present longitudinal study examines adaptive functioning in infants of mothers diagnosed as clinically depressed at 5 months but remitted at 15 and 24 months. Fifty-five U. S. mothers with early, remitted clinical depression and 132 mothers without postpartum depression completed the Vineland Adaptive Behavior Scales about their infants at 15 and 24 months. Between groups, mothers were equivalent in age, ethnicity, marital status, and receptive vocabulary (a proxy for verbal intelligence), and infants were equivalent in age and distribution of gender. Controlling for maternal education and parity, mothers with early, remitted clinical depression and mothers with no postpartum depression rated their infants similarly on communication, daily living skills, and socialization. Mothers with early, remitted clinical depression rated their infants poorer in motor skills. Girls were rated more advanced than boys in communication at 24 months and daily living skills at 15 and 24 months. Rated infant adaptive behavior skills increased from 15 to 24 months. With exceptions, adaptive functioning in infants may be robust to early, remitted maternal depression, and adaptive functioning presents a domain to promote positive development in this otherwise vulnerable population.

Individual differences in children's movement variability in a virtual reality playground task

Children's movements are highly complex, and thus require measurements that capture various gross motor strategies. This study examined whether aspects of individual differences in children's gross motor movement patterns could be captured in virtual reality (VR) and how motor movements could be conceptualized through freezing-freeing patterns of degrees of freedom. To this end, a three-minute VR scenario was developed for children to freely explore, play, and move around without further instructions, and their movement strategies were simultaneously captured by a non-invasive inertial motion capture system. Sixty-four children aged 7-10 (boys: n = 37, girls: n = 27) participated. The results of correlational and principal component analysis (PCA) on measures of variability of upper extremities indicated significant relationships between nearly all measures (r = 0.31-0.69, p < 0.05). Similarly, a PCA on variability from joint movements in the lower extremities indicated relatively high intercorrelations (r = 0.31-0.71, p < 0.01). A pattern of four different variability profiles was indicated in the interrelationship between the upper and lower body. These findings emphasize the value of using innovative measurements and whole-body motion capture to disentangle individual differences in children's movement variability in product- and process-oriented assessments of gross motor competence.

DNA methylation at birth and fine motor ability in childhood: an epigenome-wide association study with replication

Lower fine motor performance in childhood has been associated with poorer cognitive development and neurodevelopmental conditions such as autism spectrum disorder, yet, biological underpinnings remain unclear. DNA methylation (DNAm), an essential process for healthy neurodevelopment, is a key molecular system of interest. In this study, we conducted the first epigenome-wide association study of neonatal DNAm with childhood fine motor ability and further examined the replicability of epigenetic markers in an independent cohort. The discovery study was embedded in Generation R, a large population-based prospective cohort, including a subsample of 924 ~ 1026 European-ancestry singletons with available data on DNAm in cord blood and fine motor ability at a mean (SD) age of 9.8 (0.4) years. Fine motor ability was measured using a finger-tapping test (3 subtests including left-, right-hand and bimanual), one of the most frequently used neuropsychological instruments of fine motor function. The replication study comprised 326 children with a mean (SD) age of 6.8 (0.4) years from an independent cohort, the INfancia Medio Ambiente (INMA) study. Four CpG sites at birth were prospectively associated with childhood fine motor ability after genome-wide correction. Of these, one CpG (cg07783800 in GNG4) was replicated in INMA, showing that lower levels of methylation at this site were associated with lower fine motor performance in both cohorts. GNG4 is highly expressed in the brain and has been implicated in cognitive decline. Our findings support a prospective, reproducible association between DNAm at birth and fine motor ability in childhood, pointing to GNG4 methylation at birth as a potential biomarker of fine motor ability.

Distinct clusters of movement entropy in children's exploration of a virtual reality balance beam

Although assessing motor competence is vital to advancing current understandings of motor development and its significance in various fields, no consensus exists on how the construct should be operationalised and measured. Existing approaches to assessing motor competence in children typically involve applying qualitative and/or quantitative scoring procedures in which children's performance is evaluated according to certain levels of assessment-specific task performance dependent upon predefined sets of instructions and procedures. Building upon ecological dynamics as a framework, different levels of motor competence can be identified in children's attempts to coordinate their degrees of freedom while trying to complete the interactive task and environmental constraints. Given the dynamic, nonlinear features of that coordinating process, assessments need to consider the inherit structure of inter- and intra-individual variability in patterns of movement. Against that background, we investigated 7-10-year-old children's (n = 58) whole-body joint kinematics as they freely explored a balance beam in a virtual reality playground. Specifically, we used exploratory cluster analysis to examine the discriminatory capability of utilising joint-specific sample entropy as a window into individual differences in movement coordination that emerged from children's exploration of the constraints embedded in the virtual task. Among the results, three clusters of children with distinct profiles of movement variability emerged, all of which showed heterogeneous levels of repeatability in joint movements in combination with the level of spatiotemporal exploration on the balance beam that could not be explained by between-cluster differences in age and gender distributions. Those findings suggest that entropy from whole-body movements can be used to cluster children into distinct groups with different profiles regarding the structure of movement variability, which can inform new understandings and the development of gross motor competence assessments for children.

Early Motor Developmental Milestones and Personality Traits in Midlife: A 50-Year Follow-Up Study

Background The purpose of this study was to investigate if infants' age at attaining motor developmental milestones is associated with the big five personality traits 50 years later. Methods Mothers of 8395 infants from the Copenhagen Perinatal Cohort recorded a total of 12 motor developmental milestones during the first year of their infant's life. Information on at least one milestone was available for 1307 singletons with adult follow-up scores on the NEO-Five-Factor Inventory. The mean age at personality testing was 50.1 years. Results Slower attainment of motor milestones was associated with increased neuroticism and lower conscientiousness in midlife. All 12 motor developmental milestones explained a total of 2.4% of the variance in neuroticism, while they explained 3.2% of the variance in conscientiousness. These results remained significant after adjustment for the included family and perinatal covariates, as well as adult intelligence. Discussion The personality trait of neuroticism is a general risk factor for psychopathology and has in young adulthood been found to be associated with early motor development. However, evidence on associations of motor developmental milestones with other personality traits has been non-existent. These findings suggest that delays in early motor development may not only characterise individuals with later psychopathology, including schizophrenia, but may also be associated with personality traits such as neuroticism and conscientiousness through the life course.

Modeling gross motor developmental curves of extremely and very preterm infants using the AIMS home-video method

BACKGROUND

Motor development is one of the first signals to identify whether an infant is developing well. For very preterm (VPT) infants without severe perinatal complications, little is known about their motor developmental curves.

AIMS

Explore gross motor developmental curves from 3 until 18 months corrected age (CA) of VPT infants, and related factors. Explore whether separate profiles can be distinguished and compare these to profiles of Dutch term-born infants.

STUDY DESIGN

Prospective cohort study with parents repeatedly recording their infant, using the Alberta Infant Motor Scale (AIMS) home-video method, from 3 to 18 months CA.

SUBJECTS

Forty-two Dutch infants born ≤32.0 weeks gestational age and/or with a birthweight (BW) of <1500 g without severe perinatal complications.

OUTCOME MEASURES

Gross motor development measured with the AIMS.

RESULTS

In total 208 assessments were analyzed, with 27 infants ≥five assessments, 12 with <four, and three with one assessment. Sigmoid-shaped gross motor curves show unidirectional growth and variability. No infant or parental factors significantly influenced motor development, although a trend was seen for the model where lower BW, five-minute Apgar score <7, and Dutch native-speaking parents were associated with slower motor development. Three motor developmental profiles of VPT infants were identified, early developers, gradual developers, and late bloomers, which until 12 months CA are comparable in shape and speed to profiles of Dutch term-born infants.

CONCLUSIONS

VPT infants show great intra- and interindividual variability in gross motor development, with three motor profiles being distinguished. From 12 months CA onwards, VPT infants appear to develop at a slower pace. With some caution, classifying infants into motor developmental profiles may assist clinical decision-making.

Factors Associated with Motor Competence in Preschoolers from a Brazilian Urban Area

Background

Preschool is a crucial period for developing motor skills.

Objective

This study evaluated factors associated with motor competence in preschoolers from a Brazilian urban area.

Methods

A total of 211 preschoolers (51.2% girls and 48.8% boys) were evaluated. Body mass index was calculated; the Brazilian Economic Research Criterion, the Mini-Mental Scale (MMC) and the Early Childhood Environment Rating Scale®, Revised (ECERS-R™) were applied; the Habitual Physical Activity time was recorded; the Test of Gross Motor Development (TGMD-2) was performed. Univariate analysis was performed using simple linear regression for the independent variables, considering the motor test subscales as dependent variables. Variables with p < 0.20 in the univariate analysis were considered for the multiple linear regression model and were entered into the stepwise method.

Results

The independent variables remaining in the Standard Score Locomotor model were BMI, presence of park at school, and MMC (R2 = 0.16). The independent variables remaining in the Standard Object Control score were MMC and gender (R2 = 0.03). The variables associated with the highest scores of Gross Motor Quotient were MMC, body mass index, and presence of a park at school, respectively (R2 = 0.11).

Conclusion

Male eutrophic preschoolers who are physically active and attend schools with parks or courtyards in a Brazilian urban area have the highest scores for global cognitive function and motor competence.

Movement Difficulties at Age Five Among Extremely Preterm Infants

BACKGROUND AND OBJECTIVES

Children born extremely preterm (EPT), <28 weeks' gestational age, face higher risks of movement difficulties than their term-born peers. Studies report varying prevalence estimates and prognostic factors identifying children who could benefit from early intervention are inconsistent. This study investigated the prevalence of movement difficulties in children born EPT and associated risk factors.

METHODS

Data come from a population-based EPT birth cohort in 2011 and 2012 in 11 European countries. Children without cerebral palsy were assessed at 5 years of age (N = 772) with the Movement Assessment Battery for Children-Second Edition, which classifies movement difficulties as none (>15th percentile), at risk (6th-15th percentile) and significant (≤5th percentile). Associations with sociodemographic, perinatal, and neonatal characteristics collected from obstetric and neonatal medical records and parental questionnaires were estimated using multinomial logistic regression.

RESULTS

We found 23.2% (n = 179) of children were at risk for movement difficulties and 31.7% (n = 244) had significant movement difficulties. Lower gestational age, severe brain lesions, and receipt of postnatal corticosteroids were associated with significant movement difficulties, whereas male sex and bronchopulmonary dysplasia were associated with being at risk and having significant movement difficulties. Children with younger, primiparous, less educated, and non-European-born mothers were more likely to have significant movement difficulties. Differences in prevalence between countries remained after population case-mix adjustments.

CONCLUSIONS

This study confirms a high prevalence of movement difficulties among EPT children without cerebral palsy, which are associated with perinatal and neonatal risk factors as well as sociodemographic characteristics and country.

Impact of the COVID-19 Pandemic on the Motor Development of Schoolchildren in Rural and Urban Environments

Social and school closures during the COVID-19 pandemic may have led to significant stagnation in children's motor development, but precise data on this are lacking. We aimed to examine the impact of the pandemic and society closure on motor development of school children and to find differences between rural and urban environments. From the SLOfit database, we obtained anonymous results from 756 6^th grade children before the pandemic (11.3 ± 0.5 years, 52.5% boys) who performed physical fitness measurements in 2017 and 2019 in 8th grade and from 853 6^th grade children (11.4 ± 0.5 years, 51% boys) who performed measurements in 2019 and 2021, after 3 pandemic waves. The results of eight physical activity tests and the overall physical fitness index were compared between the prepandemic and the pandemic generation. We divided the sample into four groups (rural and urban prepandemic group and rural and urban pandemic group) and compared the changes in test scores between 6th and 8th grade. We found a statistically significant decrease in the physical fitness index of the pandemic generation (from 51.6 ± 29.6 to 45.8 ± 30.3) compared to the prepandemic generation (from 50.4 ± 30.5 to 50.5 ± 29.7), p < 0.001. The greatest effects of pandemic closure were found in the 600-meter run, in polygon course backwards test, in the number of sit-ups in 60 seconds, and in the 60-meter sprint. Children from rural areas showed worse decrement in physical fitness index compared to urban areas, except for 600-meter run. We conclude that the pandemic closure has had a significant inhibitory effect on the motor development of schoolchildren and has reduced their overall physical fitness with worse decline in rural areas. The pandemic generation of children needs more physical education in schools and other systemic interventions to mitigate these consequences.

Effects of Indoor Air Pollution on the Development of Children under Five Years of Age in Sri Lanka

Air pollution is a multifaceted environmental toxin affecting the Central Nervous System (CNS) through diverse pathways. The CNS of young children is particularly susceptible to the detrimental effects of toxins, as brain development continues postnatally with the formation of interneuronal connections, glial cell proliferation and myelination of axons. Indoor air pollution (IAP) from solid fuel combustion is more harmful than outdoor air pollution. Numerous air pollutants hazardous to health are released during the burning of unprocessed biomass. The primary source of fuel in Sri Lanka for cooking is biomass, mainly wood. In this study, we evaluated the influence of IAP resulting from biomass combustion on the neurodevelopment of children. In a cohort of children under five years living in a semi-urban area of Sri Lanka, neurodevelopment was assessed using Denver II developmental screening test. Air quality levels were measured (Carbon Monoxide (CO) and Particulate Matter 2.5 (PM2.5)) in a subsample. There were significantly high levels of CO and PM2.5 in the ambient air of households using biomass as the primary fuel for cooking. Children living in these households had a significantly higher number of children with ‘suspect’ developmental assessment scores in the language, social behavior and play and gross motor development domains.

Early life exposure to residential green space impacts cognitive functioning in children aged 4 to 6 years

INTRODUCTION

During early childhood, neuronal networks are highly susceptible to environmental factors. Previous research suggests that green space exposure is beneficial for cognitive functioning. Here, we investigate the associations between residential green space exposure and behavioral problems and cognitive development in children aged four to six years.

METHOD

We included children participating in the ENVIRONAGE birth cohort. Residential green spaces were calculated based on high-resolution land cover data within several buffers (50-1,000 m) around the residence. The children's behavior was assessed with the Strengths and Difficulties Questionnaire (SDQ) among 411 children. In addition, to evaluate cognitive function, 456 children completed four tasks of the Cambridge Neuropsychological Test Automated Battery (CANTAB). We used multivariate logistic and linear regression models while accounting for potential confounders and covariables.

RESULTS

An interquartile (IQR) increase of residential green space within 50 m was associated with a 38% (95% CI: 56;14) lower odds of a child having hyperactivity problems. Additionally, we found a beneficial influence of residential green space in close proximity (50-100 m) on the attention and psychomotor speed, represented by the Motor Screening Task. For example, we found a decrease of 0.45 (95% CI: -0.82;-0.09) pixel units from target center with an IQR increase of residential green space in a 50 m buffer. In addition, we observed an improved visual recognition/working memory, represented by the Delayed Matching to Sample Task within all included buffers (50-1000 m). For example, we observed a decrease of 4.91% (95 %CI: -7.46;-2.36) probability of an error occurring if the previous trial was correct and a 2.02% (95 %CI: 0.08; 3.97) increase of correct trials with an IQR increase of green space within a 100 m buffer.

CONCLUSION

This study provides additional indications for a beneficial influence of green space exposure on the development of behavioral problems and cognitive function as young as four years of age.

Household pesticide exposures and infant gross motor development in the MADRES cohort

BACKGROUND

The development of motor skills in infancy is a vital neurodevelopmental milestone. Although previous studies have explored the neurotoxic effects of agricultural pesticides on infants' motor development, limited research has examined early postnatal household pesticide use on infants' motor development, particularly among urban communities.

OBJECTIVE

This study examined the association between early postnatal household pesticide use and infants' gross and fine motor development at 6 months of age.

METHODS

Questionnaires were administered via telephone to 296 mother-infant dyads in the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) pregnancy cohort. Early life household pesticide use was assessed via questionnaire administered when infants turned 3 months old and gross and fine motor development was assessed by the Ages and Stages Questionnaire (ASQ-3) at 6 months old. Infant gross motor scores were reverse coded so that higher scores indicated lower gross motor performance. Negative binomial regressions were performed to assess the relationship between household pesticide use and infant gross motor development.

RESULTS

Infants were predominantly Hispanic (78.7%) and full term (gestational age at birth: 39.0 ± 1.9 weeks), with 22.3% of maternal participants reporting household use of rodent and insect pesticides. Adjusting for recruitment site, maternal age, ethnicity, household income, education, infant corrected age, infant sex, and home type, infants with maternal-reported household use of rodent and insect pesticides had 1.30 times higher expected gross motor scores (95% confiidence interval 1.05, 1.61) than infants with no reported use of household pesticides, with higher scores indicating reduced gross motor performance.

CONCLUSIONS

Our results suggest household use of rodent and insect pesticides may harm infants' gross motor development in early childhood. Future research should evaluate the impact of specific household chemicals in infant biospecimens and their associations with infant motor development to confirm these findings.

A Ten-Week Motor Skills Training Program Increases Motor Competence in Children with Developmental Coordination Disorder

The present study aimed to investigate the effect of a motor skills training program in children with DCD considering their gender. The Movement Assessment Battery for Children (MABC-2) classified the children and assessed their skill changes over time. The study was implemented at four kindergartens in the Khorezm region of Uzbekistan. In the study, all the children suffered from DCD (5.17 ± 0.70 years; 10 girls), and all the indicators of MABC-2 were less than 16%. The participants were divided into an experimental group (n = 17), receiving ten weeks of motor skills training program for 45 min twice per week; and a control group (n = 7), which proceeded with exercises of everyday living. The ANCOVA showed differences between the groups in the post-test concerning each domain: manual dexterity (F _(1, 20) = 18.703, p < 0.001; η² = 0.471); aiming and catching (F _(1, 20) = 9.734, p = 0.005; η² = 0.317); balance (F _(1, 20) = 35.140, p = 0.000; η² = 0.626); and total MABC-2 test score (F _(1, 20) = 66.093, p < 0.001; η² = 0.759), with all the children in the EG exhibiting better results. The Wilcoxon test revealed statistically significant differences for the EG between moments for all the variables (p < 0.001) but not for the CG (p > 0.050). The effectiveness of the intervention program was similar across both genders. The study suggests that a 10 week motor skills training program can increase the quality of children’s motor competence and represent a valuable procedure for physical education specialists to enhance motor competence for children with DCD.

The Relationship between Social Environmental Factors and Motor Performance in 3- to 12-Year-Old Typically Developing Children: A Systematic Review

Motor performance during childhood is important for prosperity in life, and the social environment may contain potentially important and modifiable factors associated with motor performance. Therefore, the aim of this systematic review was to identify social environmental factors associated with motor performance in 3- to 12-year-old typically developing children. Four electronic databases were searched, which resulted in 31 included studies. The methodological quality was determined using the Quality of Prognosis Studies in Systematic Reviews tool. Most studies were conducted in 3-6-year-old children. In the home environment, parental beliefs in the importance of physical activity and parental behaviors matching these beliefs were related to better motor performance of children, although these relationships were often sex-dependent. The school and sports environments were investigated much less, but some preliminary evidence was found that being better liked by peers, attending a classroom with a smaller age range, having more interaction with the teacher and classmates, and having a higher educated teacher was related to better motor performance. Further research is required to further unravel the relationship between the social environment and motor skills, with a specific focus on 6-12-year-old children and environments outside of the home environment.

Factors associated with gross motor development from birth to independent walking: A systematic review of longitudinal research

AIM

The aim of this study is to gain more insight into child and environmental factors that influence gross motor development (GMD) of healthy infants from birth until reaching the milestone of independent walking, based on longitudinal research.

BACKGROUND

A systematic search was conducted using Scopus, PsycINFO, MEDLINE and CINAHL to identify studies from inception to February 2020. Studies that investigated the association between child or environmental factors and infant GMD using longitudinal measurements of infant GMD were eligible. Two independent reviewers extracted key information and assessed risk of bias of the selected studies, using the Quality in Prognostic Studies tool (QUIPS). Strength of evidence (strong, moderate, limited, conflicting and no evidence) for the factors identified was described according to a previously established classification.

RESULTS

In 36 studies, six children and 11 environmental factors were identified. Five studies were categorized as having low risk of bias. Strong evidence was found for the association between birthweight and GMD in healthy full-term and preterm infants. Moderate evidence was found for associations between gestational age and GMD, and sleeping position and GMD. There was conflicting evidence for associations between twinning and GMD, and breastfeeding and GMD. No evidence was found for an association between maternal postpartum depression and GMD. Evidence for the association of other factors with GMD was classified as 'limited' because each of these factors was examined in only one longitudinal study.

CONCLUSION

Infant GMD appears associated with two child factors (birthweight and gestational age) and one environmental factor (sleeping position). For the other factors identified in this review, insufficient evidence for an association with GMD was found. For those factors that were examined in only one longitudinal study, and are therefore classified as having limited evidence, more research would be needed to reach a conclusion.

Modeling a gross motor curve of typically developing Dutch infants from 3.5 to 15.5 months based on the Alberta Infant Motor Scale

BACKGROUND

Interindividual variability in gross motor development of infants is substantial and challenges the interpretation of motor assessments. Longitudinal research can provide insight into variability in individual gross motor trajectories.

PURPOSE

To model a gross motor growth curve of healthy term-born infants from 3.5 to 15.5 months with the Alberta Infant Motor Scale (AIMS) and to explore groups of infants with different patterns of development.

METHODS

A prospective longitudinal study including six assessments with the AIMS. A Linear Mixed Model analysis (LMM) was applied to model motor growth, controlled for covariates. Cluster analysis was used to explore groups with different pathways. Growth curves for the subgroups were modelled and differences in the covariates between the groups were described and tested.

RESULTS

In total, data of 103 infants was included in the LMM which showed that a cubic function (F(1,571) = 89.68, p < 0.001) fitted the data best. None of the covariates remained in the model. Cluster analysis delineated three clinically relevant groups: 1) Early developers (32%), 2) Gradual developers (46%), and 3) Late bloomers (22%). Significant differences in covariates between the groups were found for birth order, maternal education and maternal employment.

CONCLUSION

The current study contributes to knowledge about gross motor trajectories of healthy term born infants. Cluster analysis identified three groups with different gross motor trajectories. The motor growth curve provides a starting point for future research on motor trajectories of infants at risk and can contribute to accurate screening.

Is Quarter of Birth a Risk Factor for Developmental Coordinator Disorder in Preschool Children?

The purpose of this study was to determine the probability that preschool children have severe motor difficulties or are at risk of motor difficulties, according to quarter of birth and gender. Five hundred and eighty-eight preschool-age children were evaluated, of which 318 (54.08%) were boys and 270 (45.92%) were girls, with a mean age of 4.66 years (SD = 0.53). The Movement Assessment Battery for Children-2 (MABC-2) was used to collect the data. The results obtained were the following: Regarding students with severe motor difficulties: 6.7% born in quarter 1 (Q1); 13.3% born in the second quarter (Q2); 20.0% born in the third quarter (Q3); and 60.0% born in the fourth quarter (Q4). The probabilities found (OR) were: Q1 vs. Q2 (OR = 3.15; p < 0.05); Q1 vs. Q3 (OR = 4.68; p < 0.005); Q1 vs. Q4 (OR = 12.40; p < 0.001); Q2 vs. Q4 (OR = 4.04; p < 0.001); and Q3 vs. Q4 (OR = 2.65; p < 0.005). The adjusted ORs, with respect to the probabilities of having severe motor difficulties, were the following: Being born in Q4 is 13.03 times more likely than being born in Q1 (p < 0.001); those born in Q3 are 4.85 times more likely than those born in Q1 (p < 0.05); and those born in Q2 4.14 times more than those born in Q1 (p < 0.05). The conclusion is that children born in Q4 are more likely to be classified as children with severe difficulties compared to children born in the other quarters of the same year.

Is It Possible to Reduce the Relative Age Effect through an Intervention on Motor Competence in Preschool Children?

The purpose of the study was to find out whether a short 6-week intervention on motor competence can reduce the Relative Age Effect (RAE) of preschool children born in the first quarter, compared to those born in the fourth quarter of the same year. Seventy-six preschool children (5.20 ± 0.54 years) from Lugo (Spain) participated. A quasi-experimental pre-post-test design was used with an intervention group (n = 32) and a control group (n = 44). The Movement Assessment Battery for Children-2 (MABC-2) was used to collect data before and after the intervention. The data show that, before the intervention, there are significant differences between the control and the intervention group in favor of the former (born in the first quarter of the year) in manual dexterity (p = 0.011), balance (p = 0.002), total test score (p = 0.008), and total percentile score (p = 0.010). After the application of the specific intervention, statistically significant differences were found in aiming and catching (p < 0.001), balance (p = 0.022), total test score (p = 0.001), and total percentile score (p < 0.001) in favor of the intervention group (born in the last quarter of the year). The results obtained suggest that the application of a specific intervention on MC could positively influence the improvement of MC in preschool children (boys and girls) and reduce the differences produced by the RAE.

Changes in Motor Competence after a Brief Physical Education Intervention Program in 4 and 5-Year-Old Preschool Children

Low motor competence (MC) can cause low participation in physical activities in preschool children, and together with a high caloric intake, it can lead to obesity. Interventions on motor skills are effective in the short term to improve MC, therefore the objectives of this study were (1) to investigate the effect of a short six-week program on levels of motor competence in preschool children, and (2) to examine the effects of gender-based intervention. A total of 156 preschool children (5.20 ± 0.54 years old) from Lugo (Spain) participated. A quasi-experimental pre-post-test design was used with a control group of 76 students. The Movement Assessment Battery for Children-2nd Edition (MABC-2) was used to collect the data. Significant differences between the control and experimental groups were found after the intervention program in aiming and catching (p < 0.001), balance (p < 0.001), the total score of eight tests (p < 0.001), and total percentile score (p < 0.001). The results regarding gender in the experimental group showed a reduction in differences with respect to the initial results except in aiming and catching, where scores were higher in boys. The data suggest that the application of specific intervention programs in MC could positively influence the improvement of MC in preschool children, thus reducing differences between genders.

Gender Differences on Motor Competence in 5-Year-Old Preschool Children Regarding Relative Age

The aim of this study was to evaluate the differences on motor competence between 5-year-old boys and girls and to investigate the existence of Relative Age Effect (RAE) on their motor competence. A total of 232 preschool children were evaluated of whom 134 (57.8%) were boys and 98 (42.2%) were girls. The Movement Assessment Battery for Children-2 (MABC-2) was used to collect data. The data show a main effect on gender factor; there was a main effect in total score of manual dexterity (MD; p = 0.010), in total score of balance (Bal; p < 0.001), in total test score (TTS; p < 0.001), and in total percentile score (TPS, p < 0.001). In the semester of birth factor, there were differences in aiming and catching (A&C, p < 0.001), in Bal (p = 0.029) and in total percentile score (TPS, p = 0.010). Girls perform better in MD, Bal, TTS, and TPS than boys. Preschool children born in the first semester obtain, in general, a higher percentage and a higher percentile than their peers born in the second one. RAE is present in A&C, Bal, and TPS, with higher scores obtained by preschool children born in the first semester compared to those born in the second one.

A Narrative Review of Motor Competence in Children and Adolescents: What We Know and What We Need to Find Out

Lack of physical activity is a global public health problem causing not only morbidity and premature mortality, but it is also a major economic burden worldwide. One of the cornerstones of a physically active lifestyle is Motor Competence (MC). MC is a complex biocultural attribute and therefore, its study requires a multi-sectoral, multi-, inter- and transdisciplinary approach. MC is a growing area of research, especially in children and adolescents due to its positive association with a plethora of health and developmental outcomes. Many questions, however, remain to be answered in this field of research, with regard to: (i) Health and Developmental-related Associations of MC; (ii) Assessment of MC; (iii) Prevalence and Trends of MC; (iv) Correlates and Determinants of MC; (v) MC Interventions, and (vi) Translating MC Research into Practice and Policy. This paper presents a narrative review of the literature, summarizing current knowledge, identifying key research gaps and presenting questions for future investigation on MC in children and adolescents. This is a collaborative effort from the International Motor Competence Network (IMCNetwork) a network of academics and researchers aiming to promote international collaborative research and knowledge translation in the expansive field of MC. The knowledge and deliverables generated by addressing and answering the aforementioned research questions on MC presented in this review have the potential to shape the ways in which researchers and practitioners promote MC and physical activity in children and adolescents across the world.

Early environmental risk factors for neurodevelopmental disorders - a systematic review of twin and sibling studies

While neurodevelopmental disorders (NDDs) are highly heritable, several environmental risk factors have also been suggested. However, the role of familial confounding is unclear. To shed more light on this, we reviewed the evidence from twin and sibling studies. A systematic review was performed on case control and cohort studies including a twin or sibling within-pair comparison of neurodevelopmental outcomes, with environmental exposures until the sixth birthday. From 7,315 screened abstracts, 140 eligible articles were identified. After adjustment for familial confounding advanced paternal age, low birth weight, birth defects, and perinatal hypoxia and respiratory stress were associated with autism spectrum disorder (ASD), and low birth weight, gestational age and family income were associated with attention-deficit/hyperactivity disorder (ADHD), categorically and dimensionally. Several previously suspected factors, including pregnancy-related factors, were deemed due to familial confounding. Most studies were conducted in North America and Scandinavia, pointing to a global research bias. Moreover, most studies focused on ASD and ADHD. This genetically informed review showed evidence for a range of environmental factors of potential casual significance in NDDs, but also points to a critical need of more genetically informed studies of good quality in the quest of the environmental causes of NDDs.

The impact of choice of norms on classification of motor impairment for children born very preterm

BACKGROUND

The Movement Assessment Battery for Children-Second Edition (Movement ABC-2) is widely used to assess children's motor function, yet there is a lack of normative data for many countries.

AIMS

To assess the extent to which the application of different population reference norms for the Movement ABC-2 affects the classification and prevalence of motor impairment.

DESIGN

Data were obtained from two Portuguese regions participating in the Screening to Improve Health in Very Preterm Infants in Europe (SHIPS) Study, which was a five year follow-up of a cohort of children born at <32 weeks' gestation in 2011-2012 in 19 regions in 11 European countries. Perinatal data were extracted from medical records and the Movement ABC-2 was administered at five years of age.

SUBJECTS

Of 542 Portuguese children eligible for the five-year follow-up, 413 (76.2%) were evaluated.

OUTCOME MEASURES

Movement ABC-2 raw scores were converted to standardized scores using norms from four countries with national standardisations (UK, Netherlands/Belgium, France and Italy).

RESULTS

The prevalence of significant movement difficulties (total score ≤ 5th percentile) was 28.5% using Dutch/Flemish norms, 23.3% using French norms, 16.5% using UK norms and 11.4% using Italian norms; 10.8% and 68.3% of the children were consistently classified as having significant movement difficulties and as not having significant movement difficulties, respectively, according to any norms. However, for 20.9% of children there was a disagreement in motor function status using different norms.

CONCLUSION

The use of different test norms has a large impact on the proportion of children classified with significant movement difficulties, with implications for clinical referrals, healthcare costs and research. Our results underscore the importance of using appropriately validated tests with sound psychometric properties, and raise questions about the large differences in norms for the Movement ABC-2 in European countries.

Reliability, Consistency and Temporal Stability of Alberta Infant Motor Scale in Serbian Infants

Our study aimed to analyze the reliability, consistency, and temporal stability of the Alberta Infant Motor Scale (AIMS) in Serbian infants. Additionally, we aimed to present a percentile distribution of AIMS in the tested population. The prospective study included 60 infants that were divided into three age groups: 0-3 months, 4-7 months, and 8-14 months. The Serbian version of AIMS was tested by two raters on two different occasions (test/retest) with a five day period between tests. The observed inter-rater reliability (intraclass correlation coefficient (ICC)) was more than 0.75 for all AIMS scores, except for standing (ICC 0.655 = moderate) in the age group of 4-7 months on retest between raters. The observed intra-rater reliability (ICC) was more than 0.75 for all AIMS scores except standing (ICC 0.655 = moderate) in the age group 4-7 months in test-retest for Rater One, and for sitting (ICC 0.671 = moderate) and standing (ICC 0.725 = moderate) in the age group between 0-3 months on test-retest for Rater Two. The Serbian version of AIMS was shown to have high consistency and high reliability with good to high temporal stability. Thus, it can be used in the evaluation of infants' motor development in Serbia.

Association of preterm birth and intrauterine growth restriction with childhood motor development: Brisa cohort, Brazil

The present study investigated the association between preterm birth PT conditions, intrauterine growth restriction IUGR and the combination of both PT-IUGR with infant motor development. A cohort with 1006 children was monitored during prenatal, at birth, and two years of age. Bayley-III screening was used to evaluate of fine and gross motor skills. The data did not indicate an increased risk for motor delays in the PT or IUGR, composed mainly by mild cases. However, the combination of the conditions PT-IUGR increased the risk of delays in motor, which emphasizes the importance of monitoring the motor development of the group.

Persistent Organic Pollutants (POPs) in Fish Consumed by the Indigenous Peoples from Nenets Autonomous Okrug

Currently, monitoring of persistent organic pollutant (POP) content in various biological and environmental matrixes in the Arctic is an urgent task. The present study focused on the determination of POPs such as: PCB#28, PCB#52, PCB#101, PCB#105, PCB#118, PCB#123, PCB#153, PCB#128, p,p’-DDE, o,p’-DDE, p,p’-DDD, o,p’-DDD, hexachlorobenzene (HCB), cis-nonachlor, trans-nonachlor, cis-chlordane, trans-chlordane, mirex, 1,2,3,5-tetrachlorobenzene and 1,2,4,5-tetrachlorobenzene in fish consumed by the indigenous people of the Nenets Autonomous Okrug (NAO) of the Russian Arctic. Fish samples were analyzed by gas chromatography triple quadrupole mass spectrometry (GC-MS/MS) using the multiple reaction monitoring (MRM) technique. The obtained results show that the major POPs in fish were dichlorodiphenyltrichloroethane (DDT) breakdown products and polychlorinated biphenyls (PCB) congeners. The ∑PCB8 in pink salmon, Arctic char, navaga, humpback whitefish and northern pike were 1.54, 1.58, 1.24, 0.72 and 0.32 ng/g (ww), respectively. The main PCB congeners maximum average medium concentrations were 0.68 ng/g (ww) and 0.51 ng/g (ww) of PCB#153 in navaga and PCB#128 in pink salmon, respectively. The main DDT breakdown product was p,p’-DDE. In Arctic char, pink salmon, navaga, humpback whitefish and northern pike, the concentration of p,p’-DDE was 0.58, 1.61, 0.49, 0.63 and 0.08 ng/g (ww), respectively. A moderate positive relationship between ∑PCB8 and lipid content and a high positive relationship between ∑DDT and lipid content were observed. In fish samples with fat content <0.5% (northern pike, humpback whitefish), the amount of analyzed POPs was 2 or more times lower than that in fish species with fat content >1% (pink salmon, Arctic char). Despite the large number of fish in the diet of indigenous peoples from NAO, no significant risks were identified. Most legacy POP and organochlorine pesticides (OCPs) tend to decrease, which can be explained by past national and regional bans and restriction on their use and emission.

North Pacific Baleen Whales as a Potential Source of Persistent Organic Pollutants (POPs) in the Diet of the Indigenous Peoples of the Eastern Arctic Coasts

Among marine mammals, gray and bowhead whales contain large amounts of fat and thereby constitute crucial dietary components of the traditional diet of indigenous peoples of the Eastern Arctic. Despite the high nutritional and cultural value of gray and bowhead whales, there is a risk of persistent organic pollutant (POP) intake by indigenous individuals who use marine mammals as their main source of fat. POPs are lipophilic pollutants and are known to accumulate and magnify along the marine food web. Consumption of foods contaminated by POPs can perturb the endocrine, reproductive, and immune systems, and can potentially cause cancer. Moderate to relatively high concentrations of POPs have indeed been reported in the edible tissues of gray and bowhead whales consumed by indigenous peoples of the North Pacific Ocean. Even though their consumption is potentially harmful, there is no regular monitoring of eco-toxicants in the foods consumed by the indigenous peoples of the Eastern Arctic. In our view, the routine analyses of consumable parts of whales and of comparable nutritional items need to be included in the Russian Arctic Biomonitoring Programme.

Girls From Socioeconomically Disadvantaged Schools Exhibit Greater Object Control Skills Than Girls From Schools on the Upper Levels of Socioeconomic Development

This study compared fundamental movement skills (FMS) in children from schools on the lower and upper levels of socioeconomic status. Data were collected from 228 schoolchildren across five schools in Ireland. There were 147 children from schools of social disadvantage (Mage  = 7.67 [SD = 0.62] years; 55% boys) and 81 children from schools considered in the normal range for socioeconomic development (Mage  = 7.34 [SD = 0.26] years; 56% boys). FMS were assessed using the Test of Gross Motor Development–2. Mixed models were used to estimate differences in FMS, while controlling for the nested structure of the data and for sex, age, body mass index, and class size. There was a substantial sex×school interaction, with girls from schools of social disadvantage exhibiting greater object-control skills proficiency than their counterparts in schools on the upper tertiles of socioeconomic development (standardized effect size = 0.66 [±95% confidence limits, ±0.50]; p = .02). The suggestion that children from social disadvantage are delayed in FMS is unsupported in this cohort. Differences in the structure of physical education and types of sports undertaken by children in schools of social disadvantage in Ireland are considered as explanations for this departure from previous studies.

Establishing New Norms for Developmental Milestones

BACKGROUND AND OBJECTIVES

Pediatric surveillance of young children depends on providers' assessment of developmental milestones, yet normative data are sparse. Our objectives were to develop new norms for common milestones to aid in clinical interpretation of milestone attainment.

METHODS

We analyzed responses to the developmental screening form of the Survey of Well-being of Young Children from 41 465 screens across 3 states. Associations between developmental status and a range of child characteristics were analyzed, and norms for individual questions were compared to guidelines regarding attainment of critical milestones from the Centers for Disease Control and Prevention (CDC).

RESULTS

A contemporary resource of normative data for developmental milestone attainment was established. Lower developmental status was associated with child age in the presence of positive behavioral screening scores (P < .01), social determinants of health (P < .01), Medicaid (P < .01), male sex (P < .01), and child race (P < .01). Comparisons between Survey of Well-being of Young Children developmental questions and CDC guidelines reveal that a high percentage of children are reported to pass milestones by the age at which the CDC states that "most children pass" and that an even higher percentage of children are reported to pass milestones by the age at which the CDC states that parents should "act early." An interactive data visualization tool that can assist clinicians in real-time developmental screening and surveillance interpretation is also provided.

CONCLUSIONS

Detailed normative data on individual developmental milestones can help clinicians guide caregivers' expectations for milestone attainment, thereby offering greater specificity to CDC guidelines.

Establishing New Norms for Developmental Milestones

BACKGROUND AND OBJECTIVES

Pediatric surveillance of young children depends on providers' assessment of developmental milestones, yet normative data are sparse. Our objectives were to develop new norms for common milestones to aid in clinical interpretation of milestone attainment.

METHODS

We analyzed responses to the developmental screening form of the Survey of Well-being of Young Children from 41 465 screens across 3 states. Associations between developmental status and a range of child characteristics were analyzed, and norms for individual questions were compared to guidelines regarding attainment of critical milestones from the Centers for Disease Control and Prevention (CDC).

RESULTS

A contemporary resource of normative data for developmental milestone attainment was established. Lower developmental status was associated with child age in the presence of positive behavioral screening scores (P < .01), social determinants of health (P < .01), Medicaid (P < .01), male sex (P < .01), and child race (P < .01). Comparisons between Survey of Well-being of Young Children developmental questions and CDC guidelines reveal that a high percentage of children are reported to pass milestones by the age at which the CDC states that "most children pass" and that an even higher percentage of children are reported to pass milestones by the age at which the CDC states that parents should "act early." An interactive data visualization tool that can assist clinicians in real-time developmental screening and surveillance interpretation is also provided.

CONCLUSIONS

Detailed normative data on individual developmental milestones can help clinicians guide caregivers' expectations for milestone attainment, thereby offering greater specificity to CDC guidelines.

Concurrent validity and discriminative ability of Dutch performance-based motor tests in 5 to 6 years old children

Aim

To assess the concurrent validity and discriminative ability of total, gross and fine motor (TM, GM and FM) scores of Dutch performance-based motor tests, the Baecke-Fassaert Motor Test (BFMT) and the 8- and 4-Skills Scan (SkSc) with the Movement Assessment Battery (MABC) for children at age 5.

Method

116 Dutch children (40.3% boys) were included. Spearman’s rho correlations and area under the curves (AUC) were assessed.

Results

Correlations between the TM scores of the tests were strong (absolute values from 0.58 to .65); the correlations between the GM scores and the FM scores between and within tests were weaker (absolute values from 0.30 to 0.45). Related to the cut-off (15^th percentile) of the MABC, the AUC of the BFMT, 8- and 4-SkSc, the AUC was 0.853 (95% CI: 0.757–0.949), 0.905 (95% CI: 0.837–0.972) and 0.844 (95% CI: 0.730–0.957), respectively. At optimal cut-offs, the sensitivity and specificity of the BFMT, the 8- and 4-SkSc were 78.6 and 78.4%, 92.2 and 73.2%, 78.6 and 76.3%, respectively.

Conclusion

All tests had a reasonably high discriminative ability, but validation with the MABC-2 and adaptations are needed to meet the requirements for screening (i.e. sensitivity ≥80% and specificity ≥90%). The relatively weak correlation between GM and FM scores implies that tests should be normalized and validated for GM and FM ability, separately.

Prenatal and childhood exposure to phthalates and motor skills at age 11 years

BACKGROUND

Previous reports suggest that prenatal phthalate exposure is associated with lower scores on measures of motor skills in infants and toddlers. Whether these associations persist into later childhood or preadolescence has not been studied.

METHODS

In a follow up study of 209 inner-city mothers and their children the concentrations of mono-n-butyl phthalate (MnBP), monobenzyl phthalate (MBzP), monoisobutyl phthalate (MiBP), monomethyl phthalate (MEP), mono-carboxy-isooctyl phthalate (MCOP), and four di-2-ethylhexyl phthalate metabolites (ΣDEHP) were measured in spot urine sample collected from the women in late pregnancy and from their children at ages 3, 5, and 7 years. The Bruininks-Oseretsky Test of Motor Proficiency short form (BOT-2) was administered at child age 11 to assess gross and fine motor skills.

RESULTS

The total number of children included in the study was 209. Of the 209 children, 116(55.5%) were girls and 93 were (45%) boys. Among girls, prenatal MnBP(b=-2.09; 95%CI: [-3.43, -0.75]), MBzP (b=-1.14; [95%CI: -2.13, -0.14]), and MiBP(b=-1.36; 95%CI: [-2.51, -0.21] and MEP(b=-1.23 [95%CI: -2.36, -0.11]) were associated with lower total BOT-2 composite score. MnBP (b= -1.43; 95% CI: [-2.44, -0.42]) was associated with lower fine motor scores and MiBP(b = -0.56; 95% CI: [-1.12, -0.01]) and MEP (b = -0.60; 95% CI: [-1.14, -0.06])was associated with lower gross motor scores. Among boys, prenatal MBzP (b = -0.79; 95% CI: [-1.40, -0.19]) was associated with lower fine motor composite score. The associations between MEP measured at age 3 and the BOT-2 gross motor, fine motor and total motor score differed by sex. In boys, there was an inverse association between ΣDEHP metabolites measured in childhood at ages 3 (b = -1.30; 95% CI: [-2.34, -0.26]) and 7 years (b = -0.96; 95% CI: [-1.79, -0.13]), and BOT-2 fine motor composite scores.

CONCLUSIONS

Higher prenatal exposure to specific phthalates was associated with lower motor function among 11- year old girls while higher postnatal exposure to ΣDEHP metabolites was associated with lower scores among boys. As lower scores on measures of motor development have been associated with more problems in cognitive, socioemotional functioning and behavior, the findings of this study have implications related to overall child development.

Evaluation of selected polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane (DDT) in fresh root and leafy vegetables using GC-MS

Persistent organic pollutants (POPs) are dangerous and toxic pollutants that may cause adverse effects on human and animal health, including death. POPs such as polychlorinated biphenyls (PCBs) and pesticides are subtly released into the environment from industrial and agricultural use. Global circulation is due to their trans-boundary transport capacity, contingent on aerodynamic and hydrological properties. Plants have capacity to take-up POPs, and these bio-magnify along heterotrophic transfer pathways. In this study, levels of selected 6-PCB congeners and 3- DDTs in some leaf and root vegetables were investigated. Leaf and root vegetables were collected from different horticultural farms areas in Cape Town. The 6-PCBs and 3-DDTs were recovered from the samples using solid phase extraction(SPE), followed by GC-MS analysis. The ΣPCBs and ΣDDT (on-whole basis), were ranged: 90.9–234 ng/g and 38.9–66.1 ng/g respectively. The 3-PCBs and 6-DDTs levels were slightly higher in leaf vegetables compared to root vegetables. The detection of PCBs and DDTs in the vegetables suggest the probable use of PCBs containing pesticides. Although the observed concentrations were below the WHO maximum residue limits, consumption of such contaminated leaf and root vegetables portend a health risk.

The effect of Atlantic salmon consumption on the cognitive performance of preschool children - A randomized controlled trial

BACKGROUND AND AIMS

Long chain polyunsaturated n-3 fatty acids (LC-PUFA) are of functional and structural importance for brain development. Observational studies have shown positive relations between fatty fish consumption and cognitive performance in children, but Results from intervention studies using supplementary n-3 LC-PUFA are conflicting. Salmon is a good source of n-3 LC-PUFA, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We tested the hypothesis that an increased dietary salmon intake results in better cognitive outcomes than a meat based diet.

METHODS

Children (n = 205, age 4-6 years) in this trial were individually randomized to eating meals containing farmed Atlantic salmon or meat three times weekly for 16 weeks. Pre- and post-intervention a cognitive test (Wechsler Preschool and Primary Scale of Intelligence, 3rd edition, WPPSI-III) and a fine-motor coordination test (Nine Hole Peg Test, 9-HPT) were performed. Biochemical analyses included glycerophospholipid fatty acid profiles in plasma and cheek cells, serum 25-hydroxyvitamin D, and urinary iodine concentration. Dietary intake before and during the study were determined using food frequency questionnaires.

RESULTS

Intakes of EPA, DHA, vitamin D and iodine were higher in the salmon than the meat group, but on biomarker level only EPA and DHA increased significantly in the salmon group compared to the meat group (p < 0.001). In general linear models no significant differences between the intervention groups were found in the scale scores of the WPPSI-III tests and the 9-HPT. In analyses of the raw scores, the salmon group showed significantly better improvement in two of the eight raw scores compared to the meat group (symbol search p = 0.038, picture concepts p = 0.047).

CONCLUSIONS

Intake of farmed Atlantic salmon led to a greater increase of the raw scores of the picture concept and symbol search subtests, while in the six other subtests raw scores were not different between the groups. This might indicate a modest positive association of salmon intake with the performance of preschool children in some subtests evaluating fluid intelligence but does not suggest an influence on global IQ development.

CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE

ClinicalTrials.gov registration number: NCT01951937.

Prenatal lead, cadmium and mercury exposure and associations with motor skills at age 7 years in a UK observational birth cohort

BACKGROUND

Lead and mercury are freely transferred across the placenta, while cadmium tends to accumulate in the placenta. Each contributes to adverse neurological outcomes for the child. Although prenatal heavy metal exposure has been linked with an array of neurodevelopmental outcomes in childhood, its association with the development of motor skills in children has not been robustly studied.

AIMS/OBJECTIVE

The aim of the present study was to investigate the association between prenatal exposure to lead, cadmium and mercury, measured as maternal blood concentrations during pregnancy, and motor skills, measured as subtests of the Movement Assessment Battery for Children (Movement ABC) at age 7 years in a large sample of mother-child pairs enrolled in a UK observational birth cohort study (Avon Longitudinal Study of Parents and Children, ALSPAC).

METHODS

Whole blood samples from pregnant women enrolled in ALSPAC were analysed for lead, cadmium and mercury. In a complete case analysis (n = 1558), associations between prenatal blood concentrations and child motor skills assessed by Movement ABC subtests of manual dexterity, ball skills and balance at 7 years were examined in adjusted regression models. Associations with probable developmental coordination disorder (DCD) were also investigated.

RESULTS

The mean prenatal blood levels were: lead 3.66 ± 1.55 μg/dl; cadmium 0.45 ± 0.54 μg/l; mercury 2.23 ± 1.14 μg/l. There was no evidence for any adverse associations of prenatal lead, cadmium or mercury exposure with motor skills measured at age 7 years with Movement ABC subtests in adjusted regression models. Further, there were no associations with probable DCD.

CONCLUSIONS

There was no evidence to support a role of prenatal exposure to heavy metals at these levels on motor skills in the child at age 7 years measured using the Movement ABC. Early identification of symptoms of motor skills impairment is important, however, to enable investigation, assessment and treatment.

Prenatal mercury exposure and child neurodevelopment outcomes at 18 months: Results from the Mediterranean PHIME cohort

INTRODUCTION

Neurotoxicity due to acute prenatal exposure to high-dose of mercury (Hg) is well documented. However, the effect of prenatal exposure to low Hg levels on child neurodevelopment and the question about "safety" of fish-eating during pregnancy remain controversial. International comparisons of Hg concentrations in mother-child biological samples and neurodevelopmental scores embedded in birth cohort studies may provide useful evidence to explore this issue.

MATERIALS AND METHODS

The Mediterranean (Italy, Slovenia, Croatia, and Greece) cohort study included 1308 mother-child pairs enrolled in the Public Health Impact of long-term, low-level, Mixed Element exposure in a susceptible population EU Sixth Framework Programme (PHIME). Maternal hair and venous blood, cord blood and breast milk samples were collected, and total Hg (THg) levels were measured. Demographic and socioeconomic information, lifestyles and nutritional habits were collected through questionnaires at different phases of follow-up. Children at 18 months of age underwent neurodevelopmental testing using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Multivariate linear and logistic regressions were performed, for each country, to assess the association between THg and BSID-III scores, obtaining adjusted β coefficients and odds ratios (ORs). These values were used to conduct a meta-analysis, to explore possible heterogeneity among countries and to obtain combined estimates of the association between THg exposure and BSID-III scores.

RESULTS

Median THg (ng/g) was: 704 in maternal hair, 2.4 in maternal blood, 3.6 in cord blood, and 0.6 in breast milk. THg concentrations were highest in Greece and lowest in Slovenia. BSID-III neurodevelopmental scores were higher in Croatia and Slovenia. The meta-analysis of multivariate linear models found an overall positive association between language composite score and receptive communication scaled score and increasing THg in maternal hair (n = 1086; β = 0.55; 95%CI: 0.05-1.05 and n = 1075; β = 0.12; 95%CI: 0.02-0.22, respectively). The meta-analysis of logistic regression models showed that the overall adjusted OR between THg in cord blood and suboptimal gross motor score was borderline significant (n = 882; OR = 1.03; 95%CI: 1.00-1.07). Heterogeneity was found across the four sub-cohorts for language composite score in maternal blood, and for fine motor scaled score in cord blood and breast milk. Language composite score and THg concentrations in maternal venous blood were positively related (n = 58; β = 4.29; CI95% (-0.02, 8.60)) in Croatia and an increase of 1 ng/g of THg in maternal venous blood was associated with a reduced risk for children to fall in the lowest quintile of language score by 31% (n = 58; OR = 0.69; CI 95%: 0.37, 1.01). The comparison of β coefficients obtained by multiple linear regression model showed an inverse association between fine motor score and THg concentrations in cord blood for Croatia (n = 54; β = -0.53; CI 95%: -1.10, 0.04) and Slovenia (n = 225; β = -0.25; CI 95%: -0.49, -0.01). In Slovenia THg level in breast milk was associated with suboptimal fine motor performance (n = 195; OR = 5.25; CI 95%: 1.36, 21.10).

CONCLUSIONS

This study showed an inverse relation between THg levels and developmental motor scores at 18 months, although the evidence was weak and partially internally and externally inconsistent. No evidence of detrimental effects of THg was found for cognitive and language outcomes at these concentrations and age.

Evaluation of upper limb movements in children with Down's syndrome: A systematic review

The aim of the present study was to perform a review of the literature on current quantitative clinical methods for the evaluation of upper limb movements in children and adolescents with Down syndrome, with a focus on describing the variables, protocols, motor function and motor control.

METHODS

A survey of PubMed, Scielo, BVS Bireme and PEDro databases using the following key words: upper limb and EMG and Down syndrome; upper limb and kinematics and Down syndrome; upper limb and motion analysis and Down syndrome; movement and upper limb and Down syndrome; upper limb and Down syndrome; reach and Down syndrome.

RESULTS

In all, 344 articles and five were selected to compose the present systematic review. No standardization was found among the studies analyzed with regard to data collection, data processing or procedures for the evaluation of the variables.

CONCLUSION

A kinematic evaluation is effective for the discussion of the results, but methodological differences among the studies and inconsistent results exert a negative influence on clinical interpretations and the possibility of reproducibility. The standardization of an upper limb movement evaluation protocol using kinematic analysis is important, as it would provide the basis for comparable, reproducible results and facilitate the planning of treatment interventions.

Sex differences in sensitivity to prenatal and early childhood manganese exposure on neuromotor function in adolescents

INTRODUCTION

While studies have suggested that exposure to manganese (Mn) may be associated with neurodevelopment in school-age children, there is limited information on prenatal and postnatal Mn exposures and tremor or motor function in children.

METHODS

We measured Mn levels in dentine of shed teeth, representing prenatal, early postnatal, and cumulative childhood exposure windows, from 195 children (predominantly right-handed, 92%) in Italy. Pursuit Aiming, Luria Nebraska Motor Battery, as well as Tremor and Sway system from Computerized Adaptive Testing System (CATSYS) were administered at 11-14 years old. We examined the relationships of tooth Mn (ln-transformed) with motor function using multivariable linear regressions and generalized additive models, adjusting for age, sex, and socioeconomic status index. Effect modification by sex was also examined.

RESULTS

We found that higher prenatal Mn was associated with better body stability in boys in a number of sway tests (including mean sway, transversal sway, sagittal sway, sway area, and sway intensity), while Mn was associated with poorer performance in girls on all of these metrics (all p for Mn × sex interaction < 0.05). Higher prenatal Mn was also modestly associated with better hand/finger and eye-hand coordination in boys compared to girls in sex-stratified analyses, although interaction models did not reach statistical significance. For tremor, on the other hand, higher early postnatal Mn was associated with increased right-hand center frequency in girls (p for interaction < 0.01), but increased Mn level at the later postnatal period was associated with increased center frequency in boys (p for interaction = 0.01).

CONCLUSIONS

This study, which used a direct measure of prenatal and childhood Mn exposure, suggested sex-specific critical windows of early life Mn exposure in relation to neuromotor function in adolescents. The sex-specific associations might be strongest with measures of whole body stability, for which the critical exposure window was during the prenatal period.

Relationship Between Iodine Concentration in Maternal Colostrum and Neurobehavioral Development of Infants in Shanghai, China

It is well known that iodine plays an important role in the process of early growth and development of most organs, especially the brain. However, iodine concentration in the colostrum and its association with the neurobehavioral development of infants remains unclear. Colostrums from 150 women were collected, and their iodine concentrations were measured. The median colostrum iodine level was 187.8 μg/L. The Bayley Scales of Infant and Toddler Development-III test was performed when the infants were about 18 months. The mean cognitive, language, and motor composite scores were 105.3 ± 9.8, 105.2 ± 11.1, and 104.6 ± 6.7, respectively. And the mean scores of the 5 subtests were 11.1 ± 2.0, 9.3 ± 2.0, 12.4 ± 2.3, 11.1 ± 1.2, and 10.4 ± 1.2, respectively. No statistically significant difference was observed in the cognition, language, or motor development of infants across different levels of colostrum iodine. After adjusting for a range of confounding factors, colostrum iodine concentration was a predictor of motor development, specifically gross motor development.