Seasonal variations of neuromotor development by 14 months of age: Hamamatsu Birth Cohort for mothers and children (HBC Study)

The Impact of Birth Season and Sex on Motor Skills in 2-Year-Old Children: A Study in Jinhua, Eastern China

BACKGROUND

This study investigates the effects of birth season and sex on the development of gross and fine motor skills in 2-year-old children in Jinhua, Eastern China.

METHODS

Conducted in Jinhua, a city in central Zhejiang Province, Eastern China, this research involved 225 children, assessing their gross and fine motor skills using the Peabody Developmental Motor Scales, Second Edition. Scores were adjusted for age in months to avoid the relative age effect. Statistical analyses included MANOVA to evaluate the impacts of season and sex.

RESULTS

Sex had no significant impact on overall motor development scores (p > 0.05). However, the season of birth significantly affected fine motor quotient (FMQ) and total motor quotient (TMQ) (p < 0.05). Boys' motor skills were generally unaffected by season, whereas girls born in winter exhibited superior fine motor skills compared to those born in summer.

CONCLUSIONS

Seasonal environmental factors significantly influence early motor development, particularly fine motor skills in girls. These findings highlight the importance of considering seasonal variations in early childhood interventions aimed at enhancing exercise physiology and sports performance.

Vitamin D supplementation and gross motor development: A 3-year follow-up of a randomized trial

BACKGROUND

Vitamin D status during pregnancy, early childhood and season-at-birth are implicated in gross motor development (GMD).

AIM

To test whether vitamin D intake in infancy and season-at-birth affect GMD in early childhood.

STUDY DESIGN

3-year follow up study of a single-center trial.

SUBJECTS

Healthy infants (n = 116) were allocated to 400 (standard-of-care), 800 or 1200 IU/day of vitamin D3 supplementation from 1 to 12 months; n = 70 returned for follow-up at 3-years.

OUTCOME MEASURES

The main outcome was GMD using the Peabody Developmental Motor Scales-2 which includes gross motor quotient (GMQ) and stationary, locomotion and object manipulation subtests.

RESULTS

GMQ scores were normal (≥85) in 94 %. An interaction between dosage group and season-at-birth (p = 0.01) was observed for GMQ and stationary standardized score; among winter/spring born children, the 1200 IU/d scored higher vs. 400 and 800 IU/d groups. Object manipulation standardized score was higher (p = 0.04) in children in the 1200 vs. 400 IU/d group, without interaction with season-at-birth.

CONCLUSIONS

GMD in young children who received 400 IU/d of supplemental vitamin D in infancy is not influenced by season-at-birth. This dose of vitamin D of 400 IU/d as recommended in North America adequately supports GMD. The modest enhancement in GMD with 1200 IU/d in winter/spring born children requires further study.

Achievement of Developmental Milestones Recorded in Real Time: A Mobile App-Based Study

OBJECTIVE

To clarify the characteristics of milestone achievement of Japanese infants using data assessed and recorded in real time via a Web-based app by caregivers.

STUDY DESIGN

Between 2014 and 2019, the achievement of developmental milestones of 16 627 Japanese infants were recorded via the mobile app Papatto Ikuji along with pertinent information including sex, birth date, anthropometric measurements, and information on feeding. The milestones consisted of 20 items belonging to 4 domains: personal-social, fine motor-adaptative, language, and gross motor. The distribution of age at milestone achievement was compared with 4 conventional normative data. Subgroup analyses according to sex, season of birth, and feeding methods were performed with restricted mean survival time analysis.

RESULTS

Age distributions of milestone achievement were generally similar in the app-based and conventional data. The exception was "Smile responsively," for which the age at achievement seemed higher in the app-based data. Subgroup analyses showed female-dominant sex differences in the achievement of person-social and language milestones. The results also showed seasonality in achievement of gross motor milestones, with earlier achievement in infants born in winter compared with those born in summer.

CONCLUSIONS

We describe mobile app-based data on developmental milestone achievements that were recorded in real time. The app-based data were generally comparable with conventional normative data, suggesting that its potential to assess the development of children in real time. This could be used complementarily with the current well-child visits at scheduled time points.

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.

Birth month and infant gross motor development: Results from the Japan Environment and Children's Study (JECS)

The association between birth month and neurodevelopmental or psychiatric disorders has been investigated in a number of previous studies; however, the results have been inconsistent. This study investigated the association between birth month and child gross motor development at 6 and 12 months of age in a large cohort of infants (n = 72,203) participating in the Japan Environment and Children’s Study (JECS). Gross motor development was assessed using the Ages and Stages Questionnaire (ASQ-3). At 6 months and 12 months, 20.7% and 14.2%, respectively, had ASQ-3 indications of gross motor problems. Birth month was strongly associated with gross motor development at both time points, particularly at 6 months. Summer-born infants had the worst outcomes at both 6 months and 12 months of age. This outcome applied to the ASQ-3 score itself and to the adjusted Relative Risk (aRR), with the highest aRRs (relative to January-born) among August-born (aRR 2.51; 95%CI 2.27–2.78 at 6 months), and June-born (aRR 1.84; 95%CI 1.63–2.09 at 12 months). Boys had better scores than girls both at 6 and 12 months of age. We speculate that seasonal factors—such as maternal vitamin D deficiency and influenza infection—affecting the fetus in early pregnancy might account for the findings.

Sazonalidade e fatores de risco associados ao desenvolvimento motor de lactentes nascidos a termo

Resumo Introdução Diferentes fatores afetam o desenvolvimento motor no primeiro ano de vida, tendo sido pouco estudada a interferência da variação sazonal. Objetivo Investigar a influência da sazonalidade e de fatores de risco e proteção para o desenvolvimento motor de lactentes nascidos a termo, aos 7 e 10 meses de idade. Método Foram incluídos no estudo lactentes a termo (N=174) que vivenciaram os marcos de desenvolvimento referentes ao 2º e 3º trimestres no período de verão ou de inverno. Prontuários, entrevistas, e a Alberta Infant Motor Scale foram utilizados. Resultados A aquisição do sentar-se e engatinhar foi mais tardia nos grupos pós-inverno (p < 0,001). Quanto aos grupos de risco e sem risco para o desenvolvimento motor, observou-se, aos 7 meses, menor prevalência de planejamento da gravidez (p=0,015), menor tempo de aleitamento materno exclusivo (p=0,004) e de amamentação (p=0,012) no grupo com risco. Aos 10 meses, os lactentes do grupo de risco se caracterizaram pela menor idade gestacional (p=0,040), por serem filhos de mães mais velhas (p=0,020), maior número de irmãos (p=0,002), níveis mais elevados de pobreza (p=0,002) e maiores restrições de movimento (p=0,000). A regressão logística evidenciou que, aos 7 meses, o aleitamento materno foi a variável associada ao desenvolvimento motor, enquanto aos 10 meses, o número de filhos, a pobreza e a restrição de movimento do lactente explicaram a variação no desenvolvimento motor. Conclusão O clima frio não se mostrou um determinante isolado para o risco de atraso motor, variáveis ambientais foram mais influentes no modelo.

The relationship between birth season and early childhood development: Evidence from northwest rural China

OBJECTIVE

To examine the correlation between birth season and early childhood development.

BACKGROUND

Almost all previous studies that examine the effect of birth season on early childhood development were conducted in developed countries with a limited sample size. The present study was conducted in poor, rural areas of western China, a developing region with a continental monsoon climate.

METHOD

We administered a hemoglobin test to 650 infants (52% boys), aged 8-10 months, using a Hemocue Hb 201+ finger prick system, and assessed the cognitive and psychomotor development of sample infants using Bayley Scales of Infant Development.

RESULTS

Infants born in winter have higher Hb concentrations (t = 3.63, p < 0.001) compared to infants born in summer. Similarly, cognitive development scores (t = 5.17, p < 0.001) and psychomotor development scores (t = 10.60, p < 0.001) were significantly higher among winter-born infants.

CONCLUSION

The findings point to the involvement of birth season in early childhood development and suggest that aspects of the environment shape the experiences that contribute to early childhood development. Policy suggestions such as providing infants with ample opportunities for movement and stimulation during the cold season are discussed.

Season of Birth Predicts Emotional and Behavioral Regulation in 18-Month-Old Infants: Hamamatsu Birth Cohort for Mothers and Children (HBC Study)

Background

Previous research has demonstrated that the season of birth may predict development of emotional and behavioral regulation during childhood or adolescence. This study examined whether the season of birth predicts effortful control (i.e., the ability to voluntarily choose course of actions during conflict and to plan for the future) and aggression (i.e., the use of physical force and expression of anger toward others) in 18-month-old infants.

Methods

Participants included 885 infants who were enrolled in the Hamamatsu Birth Cohort for Mothers and Children in Hamamatsu, Japan. Seasons of birth were categorized into winter (December, January, and February), spring (March, April, and May), summer (June, July, and August), and autumn (September, October, and November). At 18 months of age, effortful control was assessed using the Early Childhood Behavior Questionnaire, and aggression was measured using the Cardiff Infant Contentiousness Scale. Structural equation modeling analysis with measurement and structural equations was conducted to test our prediction.

Results

Effortful control was higher in infants born in spring [B = 0.095, 95% CI (0.014 to 0.175), p = 0.021, β = 0.146] and summer [B = 0.078, 95% CI (0.001 to 0.156), p = 0.049, β = 0.118] than in those born in winter. In addition, aggression was lower in those born in spring [B = −0.286, 95% CI (−0.551 to −0.021), p = 0.035, β = −0.135] than those born in winter, even after controlling for seven covariates.

Conclusion

The findings suggest that season of birth may determine development of emotional and behavioral regulation skills during early infancy. Future research should pay more attention to the underlying mechanisms of the effects of birth season on development of emotional and behavioral regulation during infancy.