Objectives Current evidence is unclear due to methodological limitations. We bridge critical knowledge gaps by quantifying the longitudinal changes in movement behaviours and their correlates from early childhood through adolescence.Design Longitudinal observational cohort study.Setting General healthy child and adolescent sample in Singapore.Participants Growing Up in Singapore Towards healthy Outcomes study participants.Primary and secondary outcome measures We used wrist-worn accelerometry and proxy-reported data to examine movement behaviours (sleep, inactivity, light physical activity (PA; LPA) and moderate-to-vigorous PA (MVPA) and screen-viewing) at ages 5.5, 8, 10 and 12 years and the sociodemographic and maternal lifestyle-related correlates using linear regression models with generalised estimating equations.Results Among 837 children, sleep, LPA and MVPA declined by 3% (from 9.1 to 8.8 hours/day), 24% (from 5.8 to 4.4 hours/day) and 44% (from 71.3 to 40.1 min/day), respectively, while inactivity and screen viewing increased by 26% (from 8.0 to 10.1 hours/day) and 155% (from 1.8 to 4.6 hours/day), respectively, from ages 5.5 to 12 years. The greatest annual increase in inactivity (0.6 hour/annum) and screen-viewing (0.8 hour/annum) and decrease in LPA (0.3 hour/annum) and MVPA (10.4 min/annum) occurred from ages 8 to 10 years. Girls of Malay ethnicity and lower socioeconomic status, and whose mothers had less favourable movement behaviours, had significantly less sleep, higher inactivity and screen-viewing and/or lower PA. Maternal PA levels and/or sitting time were associated with children’s sleep, inactivity and MVPA up to age 8 years, while maternal sitting and screen-viewing behaviours were associated with children’s screen-viewing at all ages.Conclusions Using contemporaneous datasets relevant to the present day, we confirmed that children become less physically active and have longer screen-viewing as they transition into adolescence and highlighted characteristics to be prioritised in future interventions.

ABSTRACT Background Chronic malnutrition in early childhood is a multifactorial condition associated with long-term impairments, yet the physiological and gut microbial pathways underlying differential growth trajectories remain poorly understood. Objective We aimed to characterize phenotypic growth trajectories and identify the associated gut microbial and body composition signatures in infants during the first year of life. Methods We analyzed longitudinal data from birth to 12 months in a South African cohort (Soweto, n=45). Individual linear growth trajectories were modeled using the Jenss-Bayley equation, and children were clustered based on model parameters to identify phenotypic subgroups. Body composition (fat-free mass and fat mass) was measured via deuterium dilution at 6 and 12 months, and gut microbiome development was assessed using 16S rRNA gene amplicons at 4, 6, and 12 months. Results We identified distinct phenotypic subgroups including healthy growth, catch-up growth, and growth faltering, that were obscured at the cohort level. These trajectories diverged most dynamically within the first 6 months of life. Integrated analysis revealed that in the growth faltering cluster, height-for-age and fat-free mass z-scores stabilized between 6 and 12 months, whereas fat mass z-scores (FMZ) declined. This trade-off is consistent with a catabolic state where energy reserves are prioritized for lean tissue and bone growth. Furthermore, at 6 months, the growth faltering cluster was enriched with opportunistic pathobionts (e.g., Paraclostridium ). In contrast, the catch-up cluster exhibited a transient enrichment of facultative anaerobes (e.g., Enterobacter ), supporting a hypothesis that these oxygen-tolerant taxa may help bridge a transitional microbial state in partially oxygenated or inflamed environments to enable physiological recovery. Conclusions Early childhood chronic malnutrition phenotypes in South African infants can be defined by distinct microbial and body composition signatures that diverge within six months of life. Integrated interventions should target both host anabolic state and microbiome transitions to support recovery.

BACKGROUND/OBJECTIVES:Childhood obesity remains a pressing public health challenge worldwide. With screen viewing emerging as a major contributor to sedentary time, it is crucial to assess the extent to which screen viewing contributes to excessive body fat in children. The aim of this study was to examine the associations between screen time and subsequent adiposity in children from the Singapore GUSTO cohort. SUBJECTS/METHODS:At ages 2 and 3 years, parents reported their child's screen time, including television and handheld devices. Body fat was assessed repeatedly between ages 4 and 10 years using various methods, including body mass index (BMI), BMI z-score (zBMI), skinfold thicknesses, and whole-body body fat percentage using air displacement plethysmography (BOD POD®) and/or quantitative magnetic resonance (EchoMRITM). Among 935 children, we examined associations between average screen time from 2-3 years and adiposity using generalized estimating equations, adjusted for potential confounders and stratified by child sex. RESULTS:The average ( ± SD) screen time at 2-3 years was 2.5 ( ± 1.8) h/day. At 8 years, average body fat percentage measured by BOD POD® was 21.8% ( ± 9.1) in boys and 20.5% ( ± 8.9) in girls. In the overall sample, there were no associations between screen viewing time and adiposity. However, each one-hour increase in total screen time (β [95% CI] = 0.40 [0.05, 0.75] % per h/day) and television time (0.55 [0.10, 1.00] %) was associated, among boys, with greater whole-body fat percentage from 4 to 9 years. Consistent associations were found with skinfold thicknesses, but not with BMI/zBMI. No associations were found with handheld device time, nor among girls. CONCLUSIONS:Greater screen time, notably television time, was prospectively associated with greater adiposity among boys, but not in girls. Future studies should investigate the potential mediating mechanisms involved in this sex-specific relationship. STUDY REGISTRATION:This cohort study was registered on the 4th of August, 2010 and is available online at ClinicalTrials.gov: NCT01174875.

An unhealthy diet, excessive screen time, low levels of physical activity and suboptimal sleep are known risk factors for childhood overweight and obesity (OW/OB). These energy balance–related behaviors tend to co-occur and combine into “lifestyle patterns” (LPs) that may have a synergistic effect on OW/OB. However, few studies have examined these LPs before preschool age, and none investigated the possible involvement of parental feeding practices (e.g., breastfeeding and timing of complementary feeding), non-screen leisure activities and sleep quality. We aimed to identify such LPs during the first 2 years of life and assess their associations with OW/OB at age 5 years and age at adiposity rebound (AR). Participants were children from the French nationwide ELFE (Etude Longitudinale Française depuis l’Enfance) birth cohort. We used principal component analysis of 18 items characterizing parental feeding practices and children’s energy balance-related behaviors (n = 13,121) to derive LPs. We analyzed the associations of LPs with OW/OB at age 5 years (International Obesity Task Force definition; n = 8,388) and age at AR (in days; n = 7,845) using multivariable logistic and linear regression models, respectively. We identified three LPs: “Early complementary feeding, discretionary consumption, high screen time”, “Balanced diet, non-screen leisure activities”, and “Healthy feeding practices, low dairy consumption, suboptimal sleep” patterns. The first pattern was positively associated with OW/OB at age 5 years (OR [95

Most pregnant women do not reach the minimum recommended level of 150 min/week of moderate physical activity (MPA). Most previous studies of correlates focused on leisure time physical activity (LTPA) ignoring other domains of MPA (occupational, household/child care, transportation). This article aims to i) estimate the proportion of French pregnant women meeting physical activity (PA) guidelines during the last trimester of pregnancy, hypothesised to vary depending on the domains of MPA considered; and ii) explore differences in sociodemographic, and maternal health and behavioural correlates, whenever only LTPA or overall MPA is considered. We used data from 14,484 women who gave birth in 2011 as part of the French national ELFE mother-child cohort. PA during the last trimester of their pregnancy was reported using the Pregnancy Physical Activity Questionnaire. Women spending ≥450 MET-min/week in MPA (i.e., ≥150 min/week in activities at ≥3 METs) were considered reaching recommended PA levels. Sociodemographic and maternal health and behavioural correlates associated, respectively, with meeting PA guidelines for LTPA and having a high overall MPA (defined as an overall MPA ≥70th percentile) were assessed by multivariable logistic regressions. Most of the pregnant women reported engaging in LTPA during the last three months of pregnancy (92.3

Screen viewing time is associated with children’s academic and cognitive outcomes, but longitudinal studies are scarce, hindering identification of the most sensitive age periods. We assessed the associations of single and cumulative average screen viewing time with academic performance and working memory. In the Growing Up in Singapore Towards healthy Outcomes birth cohort, parents reported their child’s screen viewing time at ages 1, 1.5, 2, 3, 6 and 8 years. At ages 9 and 10.5, trained psychologists assessed academic performance (Wechsler Individual Achievement Test-Third Edition) and working memory (Letter-Number Sequencing task; Wechsler Intelligence Scale for Children-Fifth Edition). Associations of single and cumulative average screen viewing time with psychological outcomes were examined by multivariable linear regression (N = 502 children). Mean (standard deviation) screen viewing time ranged from 2.1 (2.0) hours/day at age 1 year, to 3.0 (2.2) hours/day at 8 years. In unadjusted models, higher screen viewing time from age 1 to 8 years was consistently associated with poorer academic performance at age 9 years and working memory at 10.5 years. After adjustment, effect sizes were reduced, but higher screen viewing time at ages 1 year [β = – 1.47, 95

Most mothers use screen technology during parenting activities. However, there is little compelling evidence on whether maternal technology habits can interfere with breastfeeding practices. We prospectively estimate how maternal screen use and technoference contributes to breastfeeding practices. This study comprises a population-based sample of 3863 mothers of infants (50.7% of girls) from Quebec, Canada. Mothers reported daily screen use and technoference at 5 months and breastfeeding practices at 5 and 17 months, respectively. Similar proportions of boys and girls were breastfed. 11.4% of mothers reported no breastfeeding, 30.4% did not exclusively breastfed for 6 months or less, 27.3% non-exclusively breastfed for >6 months, and 30.9% reported exclusive breastfeeding for >6 months. A multivariable multinomial regression model with survey-weighted data revealed that each additional hour of maternal daily screen use increased the odds of non-breastfeeding by 12% (OR = 1.12, 95% CI [1.02-1.22]) and of non-exclusively breastfeeding for the first 6 months by 9% (OR = 1.09 [1.03-1.15]), in comparison to mothers exclusively breastfeeding for >6 months. Reported technoference was associated with 33% lower odds of non-breastfeeding (OR = 0.67 [0.57-0.80]) and 20% lower odds of non-exclusively breastfeeding for 6 months or less (OR = 0.80 [0.73-0.88]). No difference was found between mothers non-exclusively vs exclusively breastfeeding for >6 months. Mothers who breastfed for >6 months reported more interactive interference with technology despite lower daily screen use. As technology evolves rapidly, its associated risks for breastfeeding practices represent a growing public health concern.

Changes in movement behaviors – physical activity (PA), sedentary behavior, and sleep patterns – across preconception, pregnancy, and postpartum are associated with maternal and child health but remain understudied. Longitudinal accelerometer-measured data, including weekday-weekend differences, are lacking. Understanding these patterns is essential for developing targeted interventions that account for lifestyle variations. We investigated longitudinal changes in PA, sedentary behavior, and sleep patterns throughout preconception, pregnancy, and postpartum using prospectively collected accelerometry data. In a Singapore prospective preconception cohort, women aged 18–45 wore an accelerometer on their non-dominant wrist for seven days during preconception (within one year of planned conception), mid-pregnancy (24–28 weeks), and 12-month postpartum. Valid data required measurements at all three or at least two consecutive timepoints (preconception-pregnancy or pregnancy-postpartum). Changes in PA (vigorous-, moderate-, and light-intensity), sedentary behavior, and sleep were analyzed using generalized estimating equations. Among 139 women (mean age: 30.8 years), most were under/normal weight (61.9

Background/Objectives Adequate physical literacy (PL) in children is a potential preventive measure against non-communicable diseases. Direct measurement of PL is often absent in population-wide studies, particularly in East and Southeast Asia. We assessed PL and associated individual- and environmental-level factors in Singapore children. Methods 726 participants (373 boys, 353 girls; age: 11.0±0.2 years) from a birth cohort study (GUSTO) completed a self-administered questionnaire in the Canadian Assessment of Physical Literacy Second Edition (CAPL-2) to assess affective and cognitive domains of PL. A subset of 360 children (187 boys, 173 girls) completed a modified fitness test-battery to assess physical competence. Chi-square tests of independence compared sex and ethnicity differences in PL scores. A modified three-domain composite Overall PL score was derived. Pearson’s correlation assessed PL scores against self-reported moderate-to-vigorous physical activity (MVPA) duration. Regression analysis examined associations of socio-economic status (SES) with PL, adjusting for sex, ethnicity, and MVPA. Results 72.8% of children were classified within the lower category bins of the modified Overall PL scoring framework. Self-reported MVPA duration was positively associated with modified Overall PL score (r(358)=0.13, p=0.01). After adjustment, the regression model revealed that household income was not associated with modified Overall PL scores (all p>0.05), while higher maternal education remained associated with higher scores (all p<0.01). Conclusion Low levels of PL observed in Singapore school children warrant concern for public health and disease prevention. These findings, alongside similarities in educational systems, cultural influences, and socioeconomic factors shared with countries within the region, highlight an urgent need to prioritize physical activity and PL in children across Asian contexts.

Movement behaviours, including moderate-to-vigorous-intensity physical activity (MVPA), light-intensity physical activity (LPA), sedentary behaviour (SB), and sleep, influence childhood adiposity. However, their collective impact on adiposity from a sex-specific perspective remains underexplored. Our research examined the sex-specific longitudinal associations of 24-h movement behaviours with body mass index (BMI) and abdominal adiposity among children. In the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study, we repeatedly measured 24-h movement behaviours using wrist-worn accelerometers (ActiGraph GT3x) and assessed adiposity (BMI, abdominal circumference, and MRI-based abdominal fat volumes) at three time points (ages 5.5–6, 7.5–8, and 10–10.5 years) within the same children in a longitudinal design. Compositional multivariable linear mixed-effect modelling and isotemporal substitution were used to estimate the associations. 531 children (49.5

BACKGROUND:Prenatal exposure to neurotoxic trace elements may disrupt early brain development, with diet as a major exposure pathway during pregnancy. This study examined the associations between maternal dietary exposure to trace elements during late pregnancy and child neurodevelopment at 3.5 years. METHODS:We analyzed 10,080 mother-child pairs from the Étude Longitudinale Française depuis l'Enfance (ELFE) study. Maternal dietary exposure to 14 trace elements was assessed by combining a food frequency questionnaire with trace element content data in foodstuffs. Child neurodevelopment was evaluated at 3.5 years using the Child Development Inventory (CDI). Multivariable linear regression, Bayesian kernel machine regression (BKMR) and quantile g-computation (QGC) were performed to examine joint and individual associations of the maternal dietary exposure to the trace element mixture with CDI-3.5 score, adjusting for potential confounders. RESULTS:Higher maternal dietary exposure to trace element mixture was associated with higher child neurodevelopmental score at 3.5 years in both BKMR and QGC models. Regarding individual prenatal trace element exposure, antimony was negatively associated, whereas inorganic mercury and tin were positively associated with CDI-3.5 score. Manganese and germanium showed positive associations only in multivariable linear regression models. These associations were consistent in direction with the assigned weights in QGC model. No significant associations were observed for other trace elements. CONCLUSION:We found complex associations between prenatal trace element exposure and child neurodevelopment. These findings highlight the role of trace elements in early brain development, underscoring the need for further longitudinal studies to confirm these associations and clarify underlying mechanisms.

BACKGROUND:The potential causal effects of perinatal exposure to polyunsaturated fatty acids (PUFAs) on child neurodevelopment remains controversial. OBJECTIVE:To infer causation, we assessed the association of perinatal PUFA patterns and child neurodevelopment by using conventional regression analyses and 1-sample Mendelian randomization (MR). METHODS:Among 1096 mother-child pairs from the French Etude des Déterminants Pré- et Postnatals du Développement de la Santé de L'enfant cohort, patterns of perinatal exposure to PUFAs were previously identified combining PUFA levels from maternal and cord erythrocytes, and colostrum. Child verbal, performance, and full-scale intelligence quotients (IQs) were assessed at ages 5-6 y. Among maternal fatty acid desaturase (FADS) variants genotyped, 2 candidates, rs174546 (FADS1) and rs174634 (FADS3), were selected, as instrumental variables, for the MR analysis. The association of PUFA patterns with child IQ was examined by conventional multivariable linear regression and 2-stage least-squares MR regression. RESULTS:In the conventional approach, the first pattern "high omega-3 long-chain PUFAs (LC-PUFAs), low omega-6 LC-PUFAs" was positively associated with verbal IQ [β (95% confidence interval) = 1.24 (0.27, 2.21) points per 1 standard deviation (SD) increase in pattern] and full-scale IQ [1.11 (0.18, 2.05)]. This pattern was independent of FADS variants, rendering MR analysis inapplicable. The third pattern, "colostrum LC-PUFAs," was positively associated with verbal [1.11 (0.19, 2.02)], performance [1.01 (0.09, 1.93)], and full-scale IQ [1.13 (0.25, 2.01)]. The MR approach, based on genetic instruments strongly associated with the third pattern, supported the beneficial effect on performance IQ [2.93 (0.05, 5.81) points per 1 SD increase in genetically predicted pattern]. The MR also suggested a deleterious effect of the fourth pattern "linoleic acid (LA) and dihomo-gamma-linolenic acid (DGLA)" on performance IQ [-1.66 (-3.22, -0.09)]. CONCLUSIONS:These findings supported the potential beneficial effects of perinatal exposure to LC-PUFAs on child neurodevelopment while highlighting possible adverse effects associated with exposure to LA and DGLA.

The relationships between fat mass (FM), lean mass (LM), and bone mass are complex with significant implications for obesity, sarcopenia, and osteoporosis later in life. While greater LM is associated with higher BMD, the association between FM and BMD is less clear. Such relationships warrant further investigation, especially in Asians, who have a higher risk of metabolic diseases and osteoporotic fractures compared to Western populations. This study investigated the associations of LM, FM, and modifiable risk factors with BMD in Asian women aged 18-45 yr. A total of 191 women from the Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO) cohort study underwent DXA scanning at the first study visit for BMD and body composition measurements. LM, FM, and four body composition phenotypes derived from dichotomizing LM and FM were related to cohort-specific Z-scores of BMD at FN (BMDFN), LS (BMDLS), and whole body (BMDWB). Adjusting for covariates, LM showed positive associations with Z-BMDFN, [β (95%CI)], [0.38 (0.22, 0.55)], Z-BMDLS [0.43 (0.25, 0.62)], and Z-BMDWB, [0.63 (0.44, 0.81)]. Fat mass by contrast showed an inverse association only with Z-BMDWB, [-0.39 (-0.58, -0.20)]. Compared to women with healthy body composition (higher LM-lower FM), women with lower LM-higher FM had similar BMI, mean (SD) 20.9 (1.5) kg/m2 but disproportionately higher percent fat, 38.4 (2.2%), and lower Z-BMDFN [-0.58 (-0.97, -0.18)], Z-BMDLS [-0.41 (-0.81, 0.00)], and Z-BMDWB [-0.66 (-1.06, -0.25)]. Chinese women had lower BMD than Malay women. Physical activity and education attainment were positively, while the age of menarche was negatively associated with BMD. These findings in young women underscore the importance of early interventions recognizing ethnic differences in BMD to improve lifecourse musculoskeletal health. Most importantly, intervention strategies for Asian women should focus on healthy body composition beyond BMI, with a goal to preserve or increase LM.

The relationships between fat mass (FM), lean mass (LM), and bone mass are complex with significant implications for obesity, sarcopenia, and osteoporosis later in life. While greater LM is associated with higher BMD, the association between FM and BMD is less clear. Such relationships warrant further investigation, especially in Asians, who have a higher risk of metabolic diseases and osteoporotic fractures compared to Western populations. This study investigated the associations of LM, FM, and modifiable risk factors with BMD in Asian women aged 18-45 yr. A total of 191 women from the Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO) cohort study underwent DXA scanning at the first study visit for BMD and body composition measurements. LM, FM, and four body composition phenotypes derived from dichotomizing LM and FM were related to cohort-specific Z-scores of BMD at FN (BMDFN), LS (BMDLS), and whole body (BMDWB). Adjusting for covariates, LM showed positive associations with Z-BMDFN, [β (95%CI)], [0.38 (0.22, 0.55)], Z-BMDLS [0.43 (0.25, 0.62)], and Z-BMDWB, [0.63 (0.44, 0.81)]. Fat mass by contrast showed an inverse association only with Z-BMDWB, [-0.39 (-0.58, -0.20)]. Compared to women with healthy body composition (higher LM-lower FM), women with lower LM-higher FM had similar BMI, mean (SD) 20.9 (1.5) kg/m2 but disproportionately higher percent fat, 38.4 (2.2%), and lower Z-BMDFN [-0.58 (-0.97, -0.18)], Z-BMDLS [-0.41 (-0.81, 0.00)], and Z-BMDWB [-0.66 (-1.06, -0.25)]. Chinese women had lower BMD than Malay women. Physical activity and education attainment were positively, while the age of menarche was negatively associated with BMD. These findings in young women underscore the importance of early interventions recognizing ethnic differences in BMD to improve lifecourse musculoskeletal health. Most importantly, intervention strategies for Asian women should focus on healthy body composition beyond BMI, with a goal to preserve or increase LM.

INTRODUCTION:Breastfeeding has been shown to be associated with improved child cognitive performance, but the causality of this association is still debated because it tends to disappear when accounting for maternal cognitive performance and socioeconomic status. We aimed to explore the relationship between breastfeeding and the cognitive performance of children in the French general population. METHODS:From the PELAGIE woman-child cohort, which included pregnant women between 2002 and 2006 in Brittany (France), 286 children were evaluated using the Wechsler Intelligence Scale for Children (WISC-IV) and the Developmental Neuropsychological Assessment (NEPSY) scales at age 6. Associations between breastfeeding and cognitive performance were assessed using multivariable linear regression models adjusted for maternal verbal cognitive performance and education level, familial stimulation and environment (Home Observation for Measurement of the Environment scale), and Rey's Social Deprivation Index (contextual indicator). In addition, we performed structural equation modeling (SEM) to investigate the complex interrelation between these variables. RESULTS:Children who were breastfed for at least 4 months had significantly higher scores on the WISC Verbal Comprehension Index (WISC-VCI) than those who were never breastfed or who were breastfed less than 15 days (βadjusted, 4.95 points; 95% CI, 0.54-9.37). Among the 193 children who were breastfed, the duration of breastfeeding, in particular during the first 4 months, was increasingly associated with the WISC-VCI score. We also observed statistically significant associations between breastfeeding itself or the duration of breastfeeding and better performance on several NEPSY subtests, including visual attention, design copying, arrows, and narrative memory. SEM analysis confirmed these associations. No statistical association was observed between breastfeeding and the WISC Working Memory Index or other NEPSY subtests. DISCUSSION:These data support current national and World Health Organization global 2025 targets of promoting breastfeeding for at least 4 to 6 months.

OBJECTIVES:This study aims to compare amongst preschoolers, night sleep duration derived using the automated van Hees algorithm in GGIR (GGIR_VH) against the reference Sadeh algorithm (Actilife_SD), and subjective caregiver-reported sleep diaries against Actilife_SD. METHODS:Participants were 142 preschoolers (52.1% males), age 5.5 years, from the Growing Up in Singapore Toward healthy Outcomes (GUSTO) birth cohort study. Weeklong actigraphy data was collected via the wGT3X-BT accelerometer (worn on the non-dominant wrist) with concurrent caregiver-reported sleep diaries. Analyses were conducted to compare the automated GGIR_VH and sleep diaries against the reference Actilife_SD. Intraclass correlations were calculated to compare the agreement levels. Bland-Altman plots were used to investigate the bias in the mean differences and limits of agreement (LoA). Repeated measures of ANOVAs were used to compare mean differences. RESULTS:For the intraclass correlation between automated GGIR_VH and reference Actilife_SD, there was moderate agreement for the nighttime total sleep duration (r = 0.66) and poor agreement between diary and Actilife_SD (r = 0.04). Bland-Altman plots revealed a positive bias when comparing diaries against Actilife_SD, where diaries reported longer sleep duration. In contrast, there was almost no bias and smaller LoAs for the comparison between GGIR_VH and Actilife_SD. ANOVAs showed that comparisons between diary (M = 9.36, SD = 1.16) and Actilife_SD (M = 6.93, SD = 1.12); and GGIR_VH (M = 6.76, SD = 1.30) and Actilife_SD both yielded significant differences. CONCLUSIONS:Overall, the automated GGIR_VH algorithm showed moderate agreement compared to the reference Actilife_SD. In contrast, sleep diaries overestimated sleep duration when compared to Actilife_SD.

PURPOSE:To investigate the associations between paper-based reading and writing time, screen-based time at ages 2, 3, 6 and 9 years and myopia at age 9 in the GUSTO birth cohort. METHODS:The GUSTO study recruited pregnant women from two Singapore public maternity hospitals between 2009 and 2010. Parent-reported reading and writing time, screen time and outdoor time were collected at ages 2, 3, 6 and 9 years. Cycloplegic autorefraction and axial length were measured at age 9. Myopia was defined as a spherical equivalent ≤-0.5 D. Associations between near work exposures and myopia were examined using multivariable regression with generalised estimating equations. RESULTS:Among 471 children (942 eyes), 37.3% were myopic at age 9 years. Greater reading and writing time at ages 6 and 9 were associated with higher odds of myopia at age 9 (OR [95% CI] = 1.20 [1.02-1.42] and 1.11 [1.02-1.22] per h/day, respectively). Children spending >3 h/day reading and writing at age 9 had 76% higher odds of myopia than those spending ≤3 h/day (OR = 1.76, 95% CI: 1.08-2.85). Reading and writing time at ages 2 and 3 years, and screen time at all age groups showed no significant association with myopia at age 9. CONCLUSIONS:Traditional paper-based reading and writing, but not screen time, were associated with myopia in Singaporean children. Future studies with larger samples and objective screen time measures are needed to evaluate the distinct role of screen time in myopia.

Background: The relationship between maternal obesity and childhood cognitive development remains unclear. Prior studies did not adjust for important confounders, and preterm infants are a developmentally distinct group that remains scarcely examined. Objectives: To determine whether maternal prepregnancy body mass index (BMI) is associated with offspring intelligence quotient (IQ) up to 5 years and whether this relationship varies with gestational age. Methods: Data from two French birth cohorts, EDEN (all gestational ages) and EPIPAGE-2 (preterm children born between 24 and 34 weeks of gestation), were used for this study. Maternal prepregnancy weight and height were used to calculate prepregnancy BMI. The Wechsler Preschool and Primary Scale of Intelligence was used to assess child IQ around 5 years. Multivariable models were adjusted for confounders, including socioeconomic status and paternal BMI. Results: Analytical cohorts included 1100 children from EDEN and 2629 from EPIPAGE-2. Lower intellectual functioning (full-scale IQ < 85) was observed in 8.1% of children in EDEN and 19.6% in EPIPAGE-2. The prevalence of maternal obesity was 13.6% (EDEN) and 21.3% (EPIPAGE-2) among children with lower intellectual functioning compared to 8.9% (EDEN) and 12.9% (EPIPAGE-2) among children with normal intellectual functioning. Maternal prepregnancy obesity was associated with an approximately 3-point decrease in full-scale IQ scores in fully adjusted models (adjusted beta -2.8, 95% confidence interval [CI] -5.6, -0.1 and -2.6, 95% CI -4.7, -0.6 in EDEN and EPIPAGE-2, respectively). In EDEN, maternal obesity was associated with lower scores in the verbal IQ domain. Among infants born preterm (EPIPAGE-2), maternal obesity was associated with lower scores in the processing, reasoning, and verbal IQ domains. Adjustment for paternal BMI did not change the magnitude of the relationship with maternal obesity. Conclusions: High maternal prepregnancy BMI is associated with child cognitive development around 5 years of age.

BACKGROUND/OBJECTIVE:Offspring's optimal neurodevelopment depends on maternal dietary lipids supply during the perinatal period. Dairy products are an important source of fat in Western diets. This study aimed at examining the associations between maternal dairy fat intake during pregnancy, evaluated through biomarkers in perinatal biofluids (C15:0 and C17:0) and child's cognitive outcomes. SUBJECTS/METHODS:Participants (N up to 1200) were French mother-child pairs from the EDEN cohort study. Biomarkers were assessed in the following biofluids: maternal red blood cells (RBC) membrane at 24 weeks' gestation, cord RBC membrane, and colostrum. Cognitive outcomes were language abilities scores at ages 2 and 3 years and overall cognitive development scores at ages 3 and 5-6 years. Associations were assessed using multiple linear regression models adjusted for factors related to family socioeconomic context, maternal lifestyle, and healthy diet score. Interaction of any breastfeeding duration on the associations with dairy fat biomarkers in colostrum was studied. RESULTS:Positive associations were observed between levels of C17:0 in cord RBC and C15:0 in maternal RBC with language abilities. In children breastfed for at least 6 months, C15:0 level in colostrum was positively associated with language abilities at age 3 years and overall cognitive development at ages 3 and 5-6 years whereas C17:0 level was only associated with overall cognitive development at age 3 years. CONCLUSION:Our results suggest that maternal higher intake of dairy fat during perinatal period could be potentially associated with offspring's better cognitive development. These pioneering results call for external validation to challenge their causality.

BACKGROUND:The associations of screen use with children's cognition are not well evidenced and recent, large, longitudinal studies are needed. We aimed to assess the associations between screen use and cognitive development in the French nationwide birth cohort. METHODS:Time and context of screen use were reported by parents at ages 2, 3.5 and 5.5. Vocabulary, non-verbal reasoning and general cognitive development were assessed with the MacArthur-Bates Communicative Development Inventory (MB) at age 2, the Picture Similarities subtest from the British Ability Scales (PS) at age 3.5 and the Child Development Inventory (CDI) at ages 3.5 and 5.5. Outcome variables were age-adjusted and standardized (mean = 100, SD = 15). Multiple imputations were performed among children (N = 13,763) with ≥1 screen use information and ≥1 cognitive measures. Cross-sectional and longitudinal associations between screen use and cognitive development were assessed by linear regression models adjusted for sociodemographic and birth factors related to the family and children, and children's lifestyle factors competing with screen use. Baseline cognitive scores were further considered in longitudinal analysis. RESULTS:TV-on during family meals at age 2, not screen time, was associated with lower MB scores at age 2 (β [95% CI] = -1.67 [-2.21, -1.13]) and CDI scores at age 3.5 (-0.82 [-1.31, -0.33]). In cross-sectional analysis, screen time was negatively associated with CDI scores at ages 3.5 (-0.67 [-0.94, -0.40]) and 5.5 (-0.47 [-0.77, -0.16]), and, in contrast, was positively associated with PS scores (0.39 [0.07, 0.71]) at age 3.5. Screen time at age 3.5 years was not associated with CDI scores at age 5.5 years. CONCLUSIONS:Our study found weak associations of screen use with cognition after controlling for sociodemographic and children's birth factors and lifestyle confounders, and suggests that the context of screen use matters, not solely screen time, in children's cognitive development.