Cord serum cytokines at birth and children's trajectories of mood dysregulation symptoms from 3 to 8 years: The EDEN birth cohort

There is growing evidence that in utero imbalance immune activity plays a role in the development of neurodevelopmental and psychiatric disorders in children. Mood dysregulation (MD) is a debilitating transnosographic syndrome whose underlying pathophysiological mechanisms could be revealed by studying its biomarkers using the Research Domain Criteria (RDoC) model. Our aim was to study the association between the network of cord serum cytokines, and mood dysregulation trajectories in offsprings between 3 and 8 years of age. We used the data of a study nested in the French birth cohort EDEN that took place from 2003 to 2014 and followed mother-child dyads from the second trimester of pregnancy until the children were 8 years of age. The 2002 mother-child dyads were recruited from the general population through their pregnancy follow-up in two French university hospitals. 871 of them were included in the nested cohort and cord serum cytokine levels were measured at birth. Children's mood dysregulation symptoms were assessed with the Strengths and Difficulties Questionnaire Dysregulation Profile at the ages 3, 5 and 8 years in order to model their mood dysregulation trajectories. Out of the 871 participating dyads, 53% of the children were male. 2.1% of the children presented a high mood dysregulation trajectory whereas the others were considered as physiological variations. We found a significant negative association between TNF-α cord serum levels and a high mood dysregulation trajectory when considering confounding factors such as maternal depression during pregnancy (adjusted Odds Ratio (aOR) = 0.35, 95% Confidence Interval (CI) [0.18-0.67]). Immune imbalance at birth could play a role in the onset of mood dysregulation symptoms. Our findings throw new light on putative immune mechanisms implicated in the development of mood dysregulation and should lead to future animal and epidemiological studies.

Associations of screen use with cognitive development in early childhood: the ELFE birth cohort

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.

Associations between symptoms of attention-deficit hyperactivity disorder, socioeconomic status and asthma in children

Socioeconomic status (SES) influences the risk of both physical diseases, such as asthma, and neurodevelopmental conditions, including attention-deficit/hyperactivity disorder (ADHD). Using Causal Mediation Analysis on French birth-cohort data, we found a causal pathway from SES to ADHD symptoms, in part mediated by asthma. An increase in family income at age 3 by one unit resulted in lower ADHD symptoms at age 5, by -0.37 [95% CI: -0.50, -0.24] SDQ-score-points, with additional -0.04 [95% CI: -0.08, -0.01] points reduction indirectly via asthma at age 3, both with statistical significance. Importantly, family income at age 3 exerted both direct and indirect (via asthma) negative effects on later ADHD symptoms with much higher magnitudes for the direct effect. Our findings underscore the importance of apprehending ADHD symptoms in the broader context of socioeconomic disparities, along with their comorbidities with asthma, potentially influencing public health interventions and clinical practice in managing ADHD.

Infant feeding practices and body mass index up to 7.5 years in the French nationwide ELFE study

BACKGROUND/OBJECTIVES

The infant diet represents one of the main modifiable determinants of early growth. This study aimed to investigate the associations of infant feeding practices with body mass index (BMI) until 7.5 years.

SUBJECTS/METHODS

Analyses were based on data from the French nationwide ELFE birth cohort. Data on breastfeeding (BF) and complementary feeding (CF) were collected monthly from 2 to 10 months. Infant feeding practices were characterized using principal component analyses (PCA) and hierarchical ascendant classification. BMI z-score was computed at 1, 2, 3, 5 and 7.5 years, from data collected in the child's health booklet; 7.5-year overweight was defined according to IOTF references. Associations between infant feeding practices and BMI were investigated by linear regression models adjusted for main confounders.

RESULTS

Ever breastfeeding was not associated with BMI up to 7.5 years. Compared to intermediate breastfeeding duration (1 to <3 months), longer breastfeeding duration (≥6 months) was related to lower 1-year BMI, but not at older ages. Compared to the recommended age at CF introduction (4-6 months), early CF (<4 months) was related to higher BMI up to 5 years with a similar trend at 7.5 years, but not to the risk of overweight. The PCA patterns characterized by early baby cereal introduction and late food pieces introduction or by frequent intake of main food groups were related to a lower BMI up to 7.5 years.

CONCLUSION

Breastfeeding was related with a lower BMI in infancy but not thereafter, whereas an early CF initiation (<4 months) was associated with a higher BMI in childhood.

Prenatal maternal negative life events associated with child emotional and behavioral problems in the French EDEN cohort

INTRODUCTION

Prenatal negative life events (NLEs) have been linked to adverse health outcomes in children. However, few studies examine this relationship during late childhood using trajectory analyses. Additionally, the impact of specific NLEs domains on child development remains unclear. This study aims to longitudinally explore the association between NLEs (cumulative score and specific NLEs domains) and child outcomes from birth to late childhood.

METHODS

1135 mother-child pairs from the French EDEN cohort were followed from 24 to 28 weeks of pregnancy up to 11 years of age. Maternal self-reports of prenatal NLEs were collected immediately after birth, then analyzed as a cumulative score and by NLEs domain. Children's emotional and behavioral symptoms were assessed at 4 timepoints through the Strengths and Difficulties Questionnaire.

RESULTS

Children of mothers exposed to ≥3 NLEs were more likely to follow trajectories of high levels of peer relationship problems (aOR [95 % CI] = 5.69 [1.74-18.69]), emotional symptoms (aOR [95 % CI] = 3.05 [1.08-8.63]), and conduct problems (aOR [95 %] = 3.53 [1.20-10.42]). Among the domains of NLEs, only events related to housing, finance, and living conditions were significantly associated with high emotional and behavioral difficulties trajectories (aOR [95%CI] = 2.71[1.26-5.81]).

LIMITATIONS

Potential attrition bias due to a higher dropout rate for children experiencing early indications of emotional and behavioral difficulties.

CONCLUSION

Findings support the relationship between prenatal NLEs and child outcomes, underscoring the importance of assessing prenatal stressors across life domains to identify mothers who might be in need of support.

Longitudinal effects of maternal depressive and anxious symptomatology on child hair cortisol and cortisone from pregnancy to 5-years: The EDEN mother-child cohort

Exposure to maternal depressive and anxious symptomatology in utero and after birth can affect child outcomes. One proposed mechanism is through changes in child stress hormone levels, however current studies present inconsistent findings, and further research is needed to better understand the impact of maternal mental health on child stress response. This study aims to add to the limited literature by analysing longitudinal data ranging from 24 weeks amenorrhea to 5 years postpartum among 281 mother-child pairs from the French EDEN mother-child birth cohort. Hair cortisol and cortisone data were collected from children at four time points: birth, 1, 3, and 5 years. Mothers reported depressive symptomatology via the Center for Epidemiologic Studies Depression Scale (CES-D) (at 24-weeks amenorrhea, 3-, and 5-year follow-up), and the Edinburgh Postnatal Depression Scale (EPDS) (at 4, 8 and 12 months postpartum). Prenatal anxiety symptomatology was measured via the State Anxiety Inventory (STAI) at 24 weeks amenorrhea. Group-based trajectory modelling indicated a 1-cluster classification of longitudinal child hair cortisol, cortisone and cortisol-to-cortisone ratio, as analyses did not reveal a classification by subgroups representing different child profiles. After inverse probability weighting, small effects showed prenatal depressive symptomatology was significantly associated to higher levels of child hair cortisone at one year. Prenatal anxiety symptomatology was significantly linked to higher levels of child cortisol measured at birth and cortisone at birth and at 1 year. Postpartum depressive symptomatology at 8 months was related to higher levels of cortisone among 3-year-olds. These effects were not moderated by child sex or maternal socio-economic status. Further research is needed to understand why there are associations at some time points and not others to determine any potential buffering factors.

Metabolic trade-offs in childhood: Exploring the relationship between language development and body growth

During human childhood, brain development and body growth compete for limited metabolic resources, resulting in a trade-off where energy allocated to brain development can decrease as body growth accelerates. This preregistered study explores the relationship between language skills, serving as a proxy for brain development, and body mass index at three distinct developmental stages, representing different phases of body growth. Longitudinal data from 2002 children in the EDEN mother-child cohort were analyzed using structural equation modeling. Our findings reveal a compelling pattern of associations: girls with a delayed adiposity rebound, signaling slower growth rate, demonstrated better language proficiency at ages 5-6. Importantly, this correlation appears to be specific to language skills and does not extend to nonverbal cognitive abilities. Exploratory analyses show that early environmental factors contributing to enhanced cognitive development, such as higher parental socio-economic status and increased cognitive stimulation, are positively associated with both language skills and the timing of adiposity rebound in girls. Overall, our findings lend support to the existence of an energy allocation trade-off mechanism that appears to prioritize language function over body growth investment in girls.

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

BACKGROUND

Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.

METHODS

We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5-19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median).

FINDINGS

From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness.

INTERPRETATION

The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity.

FUNDING

UK Medical Research Council, UK Research and Innovation (Research England), UK Research and Innovation (Innovate UK), and European Union.

Birth weight and head circumference discordance and outcome in preterms: results from the EPIPAGE-2 cohort

OBJECTIVE

To determine whether the relative measurement of birth weight (BW) and head circumference (HC) in preterm infants is associated with neurological outcomes.

METHODS

The EPIPAGE-2 Study included 3473 infants born before 32 weeks' gestation, classified based on their Z-score of BW and HC on the Fenton curves as concordant (≤1 SD apart) or discordant (>1 SD difference). We defined four mutually exclusive categories: discordant smaller BW (sBW) with BW-1SD and concordant small measurement (CsM) with BW and HC concordant and both ≤-1SD. Neurological outcomes at 5.5 years were evaluated with standard tests.

RESULTS

2592 (74.8%) preterm neonates were categorised as CM, 258 (7.4%) CsM, 378 (10.9%) sHC and 239 (6.9%) sBW. Compared with the CM children, those born with CsM had significantly higher risks of cognitive deficiency (adjusted OR (aOR) 1.3, 95% CI (1.0 to 2.0)), developmental coordination disorders (aOR 2.6 (1.5 to 4.4)) and need for special school services (aOR 2.3 (1.5 to 3.7)). Those born with sBW had significantly lower risk of cognitive deficiency (aOR 0.6 (0.4 to 0.9)) and the sHC group significantly higher risk of developmental coordination disorders (aOR 1.8 (1.0 to 3.2)).

CONCLUSIONS

The relative discordance of these preterm infants' BW and HC was associated with their neurological outcomes. It merits further exploration as an indirect indicator of development.

TRIAL REGISTRATION NUMBER

NCT03078439.

Sleep duration in preschool age and later behavioral and cognitive outcomes: an individual participant data meta-analysis in five European cohorts

Short sleep duration has been linked to adverse behavioral and cognitive outcomes in schoolchildren, but few studies examined this relation in preschoolers. We aimed to investigate the association between parent-reported sleep duration at 3.5 years and behavioral and cognitive outcomes at 5 years in European children. We used harmonized data from five cohorts of the European Union Child Cohort Network: ALSPAC, SWS (UK); EDEN, ELFE (France); INMA (Spain). Associations were estimated through DataSHIELD using adjusted generalized linear regression models fitted separately for each cohort and pooled with random-effects meta-analysis. Behavior was measured with the Strengths and Difficulties Questionnaire. Language and non-verbal intelligence were assessed by the Wechsler Preschool and Primary Scale of Intelligence or the McCarthy Scales of Children's Abilities. Behavioral and cognitive analyses included 11,920 and 2981 children, respectively (34.0%/13.4% of the original sample). In meta-analysis, longer mean sleep duration per day at 3.5 years was associated with lower mean internalizing and externalizing behavior percentile scores at 5 years (adjusted mean difference: - 1.27, 95% CI [- 2.22, - 0.32] / - 2.39, 95% CI [- 3.04, - 1.75]). Sleep duration and language or non-verbal intelligence showed trends of inverse associations, however, with imprecise estimates (adjusted mean difference: - 0.28, 95% CI [- 0.83, 0.27] / - 0.42, 95% CI [- 0.99, 0.15]). This individual participant data meta-analysis suggests that longer sleep duration in preschool age may be important for children's later behavior and highlight the need for larger samples for robust analyses of cognitive outcomes. Findings could be influenced by confounding or reverse causality and require replication.

Social patterning of childhood overweight in the French national ELFE cohort

An inverse social gradient in early childhood overweight has been consistently described in high-income countries; however, less is known about the role of migration status. We studied the social patterning of overweight in preschool children according to the mother's socio-economic and migration background. For 9250 children of the French ELFE birth cohort with body mass index collected at age 3.5 years, we used nested logistic regression to investigate the association of overweight status in children with maternal educational level, occupation, household income and migration status. Overall, 8.3% (95%CI [7.7-9.0]) of children were classified as overweight. The odds of overweight was increased for children from immigrant mothers (OR 2.22 [95% CI 1.75-2.78]) and descendants of immigrant mothers (OR 1.35 [1.04-2.78]) versus non-immigrant mothers. The highest odds of overweight was also observed in children whose mothers had low education, were unemployed or students, or were from households in the lowest income quintile. Our findings confirm that socio-economic disadvantage and migration status are risk factors for childhood overweight. However, the social patterning of overweight did not apply uniformly to all variables. These new and comprehensive insights should inform future public health interventions aimed at tackling social inequalities in childhood overweight.

Maternal educational attainment in pregnancy and epigenome-wide DNA methylation changes in the offspring from birth until adolescence

Maternal educational attainment (MEA) shapes offspring health through multiple potential pathways. Differential DNA methylation may provide a mechanistic understanding of these long-term associations. We aimed to quantify the associations of MEA with offspring DNA methylation levels at birth, in childhood and in adolescence. Using 37 studies from high-income countries, we performed meta-analysis of epigenome-wide association studies (EWAS) to quantify the associations of completed years of MEA at the time of pregnancy with offspring DNA methylation levels at birth (n = 9 881), in childhood (n = 2 017), and adolescence (n = 2 740), adjusting for relevant covariates. MEA was found to be associated with DNA methylation at 473 cytosine-phosphate-guanine sites at birth, one in childhood, and four in adolescence. We observed enrichment for findings from previous EWAS on maternal folate, vitamin-B12 concentrations, maternal smoking, and pre-pregnancy BMI. The associations were directionally consistent with MEA being inversely associated with behaviours including smoking and BMI. Our findings form a bridge between socio-economic factors and biology and highlight potential pathways underlying effects of maternal education. The results broaden our understanding of bio-social associations linked to differential DNA methylation in multiple early stages of life. The data generated also offers an important resource to help a more precise understanding of the social determinants of health.

Beyond the single-outcome approach: A comparison of outcome-wide analysis methods for exposome research

Outcome-wide analysis can offer several benefits, including increased power to detect weak signals and the ability to identify exposures with multiple effects on health, which may be good targets for preventive measures. Recently, advanced statistical multivariate techniques for outcome-wide analysis have been developed, but they have been rarely applied to exposome analysis. In this work, we provide an overview of a selection of methods that are well-suited for outcome-wide exposome analysis and are implemented in the R statistical software. Our work brings together six different methods presenting innovative solutions for typical problems arising from outcome-wide approaches in the context of the exposome, including dependencies among outcomes, high dimensionality, mixed-type outcomes, missing data records, and confounding effects. The identified methods can be grouped into four main categories: regularized multivariate regression techniques, multi-task learning approaches, dimensionality reduction approaches, and bayesian extensions of the multivariate regression framework. Here, we compare each technique presenting its main rationale, strengths, and limitations, and provide codes and guidelines for their application to exposome data. Additionally, we apply all selected methods to a real exposome dataset from the Human Early-Life Exposome (HELIX) project, demonstrating their suitability for exposome research. Although the choice of the best method will always depend on the challenges to be faced in each application, for an exposome-like analysis we find dimensionality reduction and bayesian methods such as reduced rank regression (RRR) or multivariate bayesian shrinkage priors (MBSP) particularly useful, given their ability to deal with critical issues such as collinearity, high-dimensionality, missing data or quantification of uncertainty.

Lifestyle patterns in European preschoolers: Associations with socio-demographic factors and body mass index

BACKGROUND

Energy balance-related behaviours (EBRBs), that is, dietary intake, screen, outdoor play and sleep, tend to combine into 'lifestyle patterns', with potential synergistic influences on health. To date, studies addressing this theme mainly focused on school children and rarely accounted for sleep, with a cross-country perspective.

OBJECTIVES

We aimed at comparing lifestyle patterns among preschool-aged children across Europe, their associations with socio-demographic factors and their links with body mass index (BMI).

METHODS

Harmonized data on 2-5-year-olds participating in nine European birth cohorts from the EU Child Cohort Network were used (EBRBs, socio-demographics and anthropometrics). Principal component analysis and multivariable linear and logistic regressions were performed.

RESULTS

The most consistent pattern identified across cohorts was defined by at least three of the following EBRBs: discretionary consumption, high screen time, low outdoor play time and low sleep duration. Consistently, children from low-income households and born to mothers with low education level had higher scores on this pattern compared to their socioeconomically advantaged counterparts. Furthermore, it was associated with higher BMI z-scores in the Spanish and Italian cohorts (β = 0.06, 95% CI = [0.02; 0.10], both studies).

CONCLUSION

These findings may be valuable in informing early multi-behavioural interventions aimed at reducing social inequalities in health at a European scale.

Associations of Maternal Educational Level, Proximity to Greenspace During Pregnancy, and Gestational Diabetes With Body Mass Index From Infancy to Early Adulthood: A Proof-of-Concept Federated Analysis in 18 Birth Cohorts

International sharing of cohort data for research is important and challenging. We explored the feasibility of multi-cohort federated analyses by examining associations between three pregnancy exposures (maternal education, exposure to green vegetation and gestational diabetes) with offspring BMI from infancy to 17 years. We used data from 18 cohorts (n=206,180 mother-child pairs) from the EU Child Cohort Network and derived BMI at ages 0-1, 2-3, 4-7, 8-13 and 14-17 years. Associations were estimated using linear regression via one-stage IPD meta-analysis using DataSHIELD. Associations between lower maternal education and higher child BMI emerged from age 4 and increased with age (difference in BMI z-score comparing low with high education age 2-3 years = 0.03 [95% CI 0.00, 0.05], 4-7 years = 0.16 [95% CI 0.14, 0.17], 8-13 years = 0.24 [95% CI 0.22, 0.26]). Gestational diabetes was positively associated with BMI from 8 years (BMI z-score difference = 0.18 [CI 0.12, 0.25]) but not at younger ages; however associations attenuated towards the null when restricted to cohorts which measured GDM via universal screening. Exposure to green vegetation was weakly associated with higher BMI up to age one but not at older ages. Opportunities of cross-cohort federated analyses are discussed.

Prenatal and childhood exposure to ambient air pollution and cognitive function in school-age children: Examining sensitive windows and sex-specific associations

BACKGROUND

Combined effect of both prenatal and early postnatal exposure to ambient air pollution on child cognition has rarely been investigated and periods of sensitivity are unknown. This study explores the temporal relationship between pre- and postnatal exposure to PM10, PM2.5, NO2 and child cognitive function.

METHODS

Using validated spatiotemporally resolved exposure models, pre- and postnatal daily PM2.5, PM10 (satellite based, 1 km resolution) and NO2 (chemistry-transport model, 4 km resolution) concentrations at the mother's residence were estimated for 1271 mother-child pairs from the French EDEN and PELAGIE cohorts. Scores representative of children's General, Verbal and Non-Verbal abilities at 5-6 years were constructed based on subscale scores from the WPPSI-III, WISC-IV or NEPSY-II batteries, using confirmatory factor analysis (CFA). Associations of both prenatal (first 35 gestational weeks) and postnatal (60 months after birth) exposure to air pollutants with child cognition were explored using Distributed Lag Non-linear Models adjusted for confounders.

RESULTS

Increased maternal exposure to PM10, PM2.5 and NO2, during sensitive windows comprised between the 15th and the 33rd gestational weeks, was associated with lower males' General and Non-verbal abilities. Higher postnatal exposure to PM2.5 between the 35th and 52nd month of life was associated with lower males' General, Verbal and Non-verbal abilities. Some protective associations were punctually observed for the very first gestational weeks or months of life for both males and females and the different pollutants and cognitive scores.

DISCUSSION

These results suggest poorer cognitive function at 5-6 years among males following increased maternal exposure to PM10, PM2.5 and NO2 during mid-pregnancy and child exposure to PM2.5 around 3-4 years. Apparent protective associations observed are unlikely to be causal and might be due to live birth selection bias, chance finding or residual confounding.

Maternal pre-pregnancy BMI and offspring hyperactivity-inattention trajectories from 3 to 8 years in the EDEN birth cohort study

Evidence suggests obesity during pregnancy is associated with offspring attention-deficit hyperactivity disorder. However, studies have been limited to evaluating the association at a single age with inadequate data on important maternal lifestyle confounders and unmeasured familial confounding. The objective of this study was to examine the association between maternal pre-pregnancy body mass index (BMI) and child hyperactivity-inattention symptoms (HIS) at 3, 5 and 8 years. Data came from the EDEN mother-child cohort. Maternal pre-pregnancy BMI status (kg/m2) was calculated using pre-pregnancy weight and height (self-reported by mothers or measured by midwives). HIS were assessed by parental-report on the Strengths and Difficulties Questionnaire at 3, 5 and 8 years of age and used to derive developmental trajectories of HIS (n = 1428). Multivariate models were adjusted for confounders including socioeconomic status, maternal lifestyle behaviours (exercise, diet, smoking, alcohol), childcare and a stimulating home environment. Paternal BMI was used as a negative control. Compared to a normal pre-pregnancy BMI, pre-pregnancy maternal obesity was positively associated with increased odds of a high HIS trajectory between 3 and 8 years old in both unadjusted and adjusted logistic regression (adjusted odds ratio [aOR] 1.87 [95% CI 1.12, 3.12]). Pre-pregnancy overweight was not significantly associated after adjustment for confounders (aOR 1.32 [0.87, 2.01]). Maternal pre-pregnancy obesity, but not overweight, was associated with increased likelihood of a high HIS trajectory in children from 3 to 8 years old. This association persisted despite controlling for many important maternal lifestyle factors and paternal BMI. Further research is warranted to identify possible mediators involved.

Prenatal dietary exposure to chemicals and allergy or respiratory diseases in children in the EDEN mother-child cohort

INTRODUCTION

Maternal exposure to food chemicals may increase the risk of allergy and respiratory disorders in offspring. We aimed to assess the association of prenatal dietary exposure to single chemicals and chemical mixtures with allergy or respiratory events reported before age 8 y in children.

METHODS

We included 1428 mother-child pairs enrolled in the EDEN mother-child cohort. Maternal dietary exposure to 209 chemicals and eight associated mixtures was investigated. Allergic and respiratory diseases (wheezing, asthma, allergic rhinitis, eczema and food allergy) were reported by parents between birth and age 8 y. Associations with the studied outcomes were evaluated with three approaches based on adjusted logistic regression, estimating odds ratios (ORs) and 95 % confidence intervals (CIs). First, food chemicals were considered individually, with correction for multiple testing. Second, chemicals selected by elastic net regression were considered simultaneously in a multiple exposure model. Third, predefined mixtures were introduced in the same adjusted logistic regression. Results are expressed as odds ratio (OR[95 % CI]).

RESULTS

Prenatal single exposure to 74 food chemicals was associated with higher risk of allergic rhinitis. Prenatal single exposure to 11 chemicals was associated with higher risk of wheezing. In the multi-exposure approach, risk of wheezing was associated with the pesticides diazinon and triadimenol, and polycyclic aromatic hydrocarbon 5-methylchrysene. Phytoestrogen resveratrol was negatively associated with lower risk of both wheezing and allergic rhinitis, and mycotoxin monoacetoxyscirpenol was negatively associated with risk of eczema. Finally, a chemical mixture composed mainly of trace elements, furans and polycyclic aromatic hydrocarbons, was associated with higher risk of allergic rhinitis (1.33 [1.02;1.73]).

CONCLUSION

Prenatal dietary exposure to chemicals was associated with risk of allergic rhinitis or wheezing up to age 8 y. A few chemicals were associated with other allergic and respiratory diseases. Larger prospective studies are needed to confirm these findings.

Availability, accessibility, and use of green spaces and cognitive development in primary school children

Green spaces may have beneficial impacts on children's cognition. However, few studies explored the exposure to green spaces beyond residential areas, and their availability, accessibility and uses at the same time. The aim of the present study was to describe patterns of availability, accessibility, and uses of green spaces among primary school children and to explore how these exposure dimensions are associated with cognitive development. Exposures to green space near home, school, commuting route, and other daily activity locations were assessed for 1607 children aged 6-11 years from six birth cohorts across Europe, and included variables related to: availability (NDVI buffers: 100, 300, 500 m), potential accessibility (proximity to a major green space: linear distance; within 300 m), and use (play time in green spaces: hours/year), and the number of visits to green spaces (times/previous week). Cognition measured as fluid intelligence, inattention, and working memory was assessed by computerized tests. We performed multiple linear regression analyses on pooled and imputed data adjusted for individual and area-level confounders. Availability, accessibility, and uses of green spaces showed a social gradient that was unfavorable in more vulnerable socioeconomic groups. NDVI was associated with more playing time in green spaces, but proximity to a major green space was not. Associations between green space exposures and cognitive function outcomes were not statistically significant in our overall study population. Stratification by socioeconomic variables showed that living within 300 m of a major green space was associated with improved working memory only in children in less deprived residential areas (β = 0.30, CI: 0.09,0.51), and that more time playing in green spaces was associated with better working memory only in children of highly educated mothers (β per IQR increase in hour/year = 0.10; 95% CI: 0.01, 0.19). However, studying within 300 m of a major green space increased inattention scores in children in more deprived areas (β = 15.45, 95% CI: 3.50, 27.40).

Blood miRNA levels associated with ADHD traits in children across six European birth cohorts

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent and highly heritable neurodevelopmental disorder of major societal concern. Diagnosis can be challenging and there are large knowledge gaps regarding its etiology, though studies suggest an interplay of genetic and environmental factors involving epigenetic mechanisms. MicroRNAs (miRNAs) show promise as biomarkers of human pathology and novel therapies, and here we aimed to identify blood miRNAs associated with traits of ADHD as possible biomarker candidates and further explore their biological relevance.

METHODS

Our study population consisted of 1126 children (aged 5-12 years, 46% female) from the Human Early Life Exposome study, a study spanning six ongoing population-based European birth cohorts. Expression profiles of miRNAs in whole blood samples were quantified by microarray and tested for association with ADHD-related measures of behavior and neuropsychological functions from questionnaires (Conner's Rating Scale and Child Behavior Checklist) and computer-based tests (the N-back task and Attention Network Test).

RESULTS

We identified 29 miRNAs significantly associated (false discovery rate < .05) with the Conner's questionnaire-rated trait hyperactivity, 15 of which have been linked to ADHD in previous studies. Investigation into their biological relevance revealed involvement in several pathways related to neurodevelopment and function, as well as being linked with other neurodevelopmental or psychiatric disorders known to overlap with ADHD both in symptomology, genetic risk, and co-occurrence, such as autism spectrum disorder or schizophrenia. An additional three miRNAs were significantly associated with Conner's-rated inattention. No associations were found with questionnaire-rated total ADHD index or with computer-based tests.

CONCLUSIONS

The large overlap of our hyperactivity-associated miRNAs with previous studies on ADHD is intriguing and warrant further investigation. Though this study should be considered explorative and preliminary, these findings contribute towards identifying a set of miRNAs for use as blood-based biomarkers to aid in earlier and easier ADHD diagnosis.

A network analysis of nutritional markers and maternal perinatal mental health in the French EDEN cohort

BACKGROUND

Perinatal maternal depression and anxiety are associated with adverse maternal outcomes, and nutrition may play an important role in their emergence. Previous research shows that certain micro and macronutrients found in different dietary patterns may associate with perinatal mood disorders. This study aims to explore relationships between nutrition during pregnancy and perinatal maternal depression and anxiety symptoms using network analyses.

METHODS

Using data from the French EDEN mother-child cohort, the sample consisted of 1438 women with available mental health outcomes (CES-D, STAI and EPDS) and nutritional markers collected from food frequency questionnaires. Four networks were constructed to explore the relationships between prenatal nutrient status, dietary patterns, and perinatal mental health, while accounting for important confounders.

RESULTS

The Healthy dietary pattern was associated with the presence of vital micronutrients, while the Western dietary pattern was consistently associated with poorer intake of specific micronutrients and contained an excess of certain macronutrients. Western dietary pattern and symptoms of postnatal depression were connected by a positive edge in both the macronutrient and micronutrient networks. Lower education levels were associated with higher Western dietary pattern scores, from which a positive edge linked to postnatal depression symptoms in both models.

CONCLUSIONS

A Western dietary pattern was associated with increased symptoms of postnatal depression in our adjusted network models; The Healthy dietary pattern was associated with essential micronutrients but not with symptoms of depression or anxiety. Perinatal mental health might be impacted by specific dietary patterns in the context of psychosocial and physical stress associated with pregnancy.

Epigenome-Wide Associations of Placental DNA Methylation and Behavioral and Emotional Difficulties in Children at 3 Years of Age

The placenta is a key organ for fetal and brain development. Its epigenome can be regarded as a biochemical record of the prenatal environment and a potential mechanism of its association with the future health of the fetus. We investigated associations between placental DNA methylation levels and child behavioral and emotional difficulties, assessed at 3 years of age using the Strengths and Difficulties Questionnaire (SDQ) in 441 mother-child dyads from the EDEN cohort. Hypothesis-driven and exploratory analyses (on differentially methylated probes (EWAS) and regions (DMR)) were adjusted for confounders, technical factors, and cell composition estimates, corrected for multiple comparisons, and stratified by child sex. Hypothesis-driven analyses showed an association of cg26703534 (AHRR) with emotional symptoms, and exploratory analyses identified two probes, cg09126090 (intergenic region) and cg10305789 (PPP1R16B), as negatively associated with peer relationship problems, as well as 33 DMRs, mostly positively associated with at least one of the SDQ subscales. Among girls, most associations were seen with emotional difficulties, whereas in boys, DMRs were as much associated with emotional than behavioral difficulties. This study provides the first evidence of associations between placental DNA methylation and child behavioral and emotional difficulties. Our results suggest sex-specific associations and might provide new insights into the mechanisms of neurodevelopment.

Environmental exposures in early-life and general health in childhood

BACKGROUND

Early-life environmental exposures are suspected to be involved in the development of chronic diseases later in life. Most studies conducted so far considered single or few exposures and single-health parameter. Our study aimed to identify a childhood general health score and assess its association with a wide range of pre- and post-natal environmental exposures.

METHODS

The analysis is based on 870 children (6-12 years) from six European birth cohorts participating in the Human Early-Life Exposome project. A total of 53 prenatal and 105 childhood environmental factors were considered, including lifestyle, social, urban and chemical exposures. We built a general health score by averaging three sub-scores (cardiometabolic, respiratory/allergy and mental) built from 15 health parameters. By construct, a child with a low score has a low general health status. Penalized multivariable regression through Least Absolute Shrinkage and Selection Operator (LASSO) was fitted in order to identify exposures associated with the general health score.

FINDINGS

The results of LASSO show that a lower general health score was associated with maternal passive and active smoking during pregnancy and postnatal exposure to methylparaben, copper, indoor air pollutants, high intake of caffeinated drinks and few contacts with friends and family. Higher child's general health score was associated with prenatal exposure to a bluespace near residency and postnatal exposures to pets, cobalt, high intakes of vegetables and more physical activity. Against our hypotheses, postnatal exposure to organochlorine compounds and perfluorooctanoate were associated with a higher child's general health score.

CONCLUSION

By using a general health score summarizing the child cardiometabolic, respiratory/allergy and mental health, this study reinforced previously suspected environmental factors associated with various child health parameters (e.g. tobacco, air pollutants) and identified new factors (e.g. pets, bluespace) warranting further investigations.

Cytokines as mediators of the associations of prenatal exposure to phenols, parabens, and phthalates with internalizing behaviours at age 3 in boys: A mixture exposure and mediation approach

Childhood internalizing disorders refer to inwardly focused negative behaviours such as anxiety, depression, and somatic complains. Interactions between psychosocial, genetic, and environmental risk factors adversely impact neurodevelopment and can contribute to internalizing disorders. While prenatal exposure to single endocrine disruptors (EDs) is associated with internalizing behaviours in infants, the associations with prenatal exposure to EDs in mixture remain poorly addressed. In addition, the biological mediators of EDs in mixture effects on internalizing behaviours remain unexplored. EDs do not only interfere with endocrine function, but also with immune function and inflammatory processes. Based on this body of evidence, we hypothetised that inflammation at birth is a plausible biological pathway through which prenatal exposure to EDs in mixture could operate to influence offspring internalizing behaviours. Based on the EDEN birth cohort, we investigated whether exposure to a mixture of EDs increased the odds of internalizing disorders in 459 boy infants at age 3, and whether the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α measured at birth were mediators of this effect. To determine both the joint and individual associations of prenatal exposure to EDs with infant internalizing behaviours and the possible mediating role of cytokines, we used the counterfactual hierarchical Bayesian Kernel Machine Regression (BKMR) regression-causal mediation analysis. We show that prenatal exposure to a complex mixture of EDs has limited effects on internalizing behaviours in boys at age 3. We also show that IL-1β, IL-6, and TNF-α are unlikely mediators or suppressors of ED mixture effects on internalizing behaviours in boys at age 3. Further studies on larger cohorts are warranted to refine the deleterious effects of EDs in mixtures on internalizing behaviours and identify possible mediating pathways.

Birth weight and subclinical cardiovascular and renal damage in a population-based study (the STANISLAS cohort study)

OBJECTIVE

Although preterm-born and low-birth-weight individuals have an increased risk of cardiovascular diseases in adulthood, little is known regarding early cardiovascular and renal damage (CVRD) or hypertension in adulthood. Our study investigated the association of birth weight with early CVRD markers as well as the heritability of birth weight in an initially healthy family-based cohort.

METHODS

This study was based on 1028 individuals from the familial longitudinal STANISLAS cohort (399 parents/629 children) initiated in 1993-1995, with a fourth examination conducted in 2011-2016. Analyses performed at the fourth visit included pulse-wave velocity, central pressure, ambulatory blood pressure, hypertension status, diastolic dysfunction/distensibility, left ventricular mass indexed (LVMI), carotid intima-media thickness and kidney damage. The family structure of the cohort allowed birth weight heritability estimation.

RESULTS

Mean (±SD) birth weight was 3.3 ± 0.6 kg. Heritability was moderate (42-44%). At the fourth visit, individuals were 37 years old (32.0-57.0), 56% were women and 13% had antihypertensive treatment. Birth weight was strongly and negatively associated with hypertension [odds ratio (OR) 95% confidence interval (CI) 0.61 (0.45-0.84)]. A nonlinear association was found with LVMI, participants with a birth weight greater than 3 kg having a higher LVMI. A positive association ( β 95% CI 5.09 (1.8-8.38)] was also observed between birth weight and distensibility for adults with normal BMI. No associations were found with other CVRD.

CONCLUSION

In this middle-aged population, birth weight was strongly and negatively associated with hypertension, and positively associated with distensibility in adults with normal BMI and with LVMI for higher birth weights. No associations were found with other CVRD markers.

Impact of parental lifestyle patterns in the preconception and pregnancy periods on childhood obesity

Introduction

High prevalence of overweight and obesity already observed in preschool children suggests the involvement of early-life risk factors. Preconception period and pregnancy are crucial windows for the implementation of child obesity prevention interventions with parental lifestyle factors as relevant targets. So far, most studies have evaluated their role separately, with only a few having investigated their potential synergistic effect on childhood obesity. Our objective was to investigate parental lifestyle patterns in the preconception and pregnancy periods and their association with the risk of child overweight after 5 years.

Materials and methods

We harmonized and interpreted results from four European mother-offspring cohorts participating in the EndObesity Consortium [EDEN, France; Elfe, France; Lifeways, Ireland; and Generation R, Netherlands] with data available for 1,900, 18,000, 1,100, and 9,500 families, respectively. Lifestyle factors were collected using questionnaires and included parental smoking, body mass index (BMI), gestational weight gain, diet, physical activity, and sedentary behavior. We applied principal component analyses to identify parental lifestyle patterns in preconception and pregnancy. Their association with risk of overweight (including obesity; OW-OB) and BMI z-scores between 5 and 12 years were assessed using cohort-specific multivariable logistic and linear and regression models (adjusted for potential confounders including parental age, education level, employment status, geographic origin, parity, and household income).

Results

Among the various lifestyle patterns derived in all cohorts, the two explaining the most variance were characterized by (1) "high parental smoking, low maternal diet quality (and high maternal sedentary behavior in some cohorts)" and, (2) "high parental BMI and low gestational weight gain." Patterns characterized by high parental BMI, smoking, low diet quality or high sedentary lifestyle before or during pregnancy were associated with higher risk of OW-OB in children, and BMI z-score at any age, with consistent strengths of associations in the main cohorts, except for lifeways.

Conclusion

This project provides insight into how combined parental lifestyle factors in the preconception and pregnancy periods are associated with the future risk of child obesity. These findings are valuable to inform family-based and multi-behavioural child obesity prevention strategies in early life.

Long-term cardiometabolic health in people born after assisted reproductive technology: a multi-cohort analysis

AIMS

To examine associations of assisted reproductive technology (ART) conception (vs. natural conception: NC) with offspring cardiometabolic health outcomes and whether these differ with age.

METHODS AND RESULTS

Differences in systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), lipids, and hyperglycaemic/insulin resistance markers were examined using multiple linear regression models in 14 population-based birth cohorts in Europe, Australia, and Singapore, and results were combined using meta-analysis. Change in cardiometabolic outcomes from 2 to 26 years was examined using trajectory modelling of four cohorts with repeated measures. 35 938 (654 ART) offspring were included in the meta-analysis. Mean age ranged from 13 months to 27.4 years but was <10 years in 11/14 cohorts. Meta-analysis found no statistical difference (ART minus NC) in SBP (-0.53 mmHg; 95% CI:-1.59 to 0.53), DBP (-0.24 mmHg; -0.83 to 0.35), or HR (0.02 beat/min; -0.91 to 0.94). Total cholesterol (2.59%; 0.10-5.07), HDL cholesterol (4.16%; 2.52-5.81), LDL cholesterol (4.95%; 0.47-9.43) were statistically significantly higher in ART-conceived vs. NC offspring. No statistical difference was seen for triglycerides (TG), glucose, insulin, and glycated haemoglobin. Long-term follow-up of 17 244 (244 ART) births identified statistically significant associations between ART and lower predicted SBP/DBP in childhood, and subtle trajectories to higher SBP and TG in young adulthood; however, most differences were not statistically significant.

CONCLUSION

These findings of small and statistically non-significant differences in offspring cardiometabolic outcomes should reassure people receiving ART. Longer-term follow-up is warranted to investigate changes over adulthood in the risks of hypertension, dyslipidaemia, and preclinical and clinical cardiovascular disease.

Correction: Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies

[This corrects the article DOI: 10.1371/journal.pmed.1004036.].

High-Dimensional Mediation Analysis: A New Method Applied to Maternal Smoking, Placental DNA Methylation, and Birth Outcomes

BACKGROUND

High-dimensional mediation analysis is an extension of unidimensional mediation analysis that includes multiple mediators, and increasingly it is being used to evaluate the indirect omics-layer effects of environmental exposures on health outcomes. Analyses involving high-dimensional mediators raise several statistical issues. Although many methods have recently been developed, no consensus has been reached about the optimal combination of approaches to high-dimensional mediation analyses.

OBJECTIVES

We developed and validated a method for high-dimensional mediation analysis (HDMAX2) and applied it to evaluate the causal role of placental DNA methylation in the pathway between exposure to maternal smoking (MS) during pregnancy and gestational age (GA) and birth weight of the baby at birth.

METHODS

HDMAX2 combines latent factor regression models for epigenome-wide association studies with max2 tests for mediation and considers CpGs and aggregated mediator regions (AMRs). HDMAX2 was carefully evaluated using simulated data and compared to state-of-the-art multidimensional epigenetic mediation methods. Then, HDMAX2 was applied to data from 470 women of the Etude des Déterminants pré et postnatals du développement de la santé de l'Enfant (EDEN) cohort.

RESULTS

HDMAX2 demonstrated increased power in comparison with state-of-the-art multidimensional mediation methods and identified several AMRs not identified in previous mediation analyses of exposure to MS on birth weight and GA. The results provided evidence for a polygenic architecture of the mediation pathway with a posterior estimate of the overall indirect effect of CpGs and AMRs equal to 44.5g lower birth weight representing 32.1% of the total effect [standard deviation (SD)=60.7g]. HDMAX2 also identified AMRs having simultaneous effects both on GA and on birth weight. Among the top hits of both GA and birth weight analyses, regions located in COASY, BLCAP, and ESRP2 also mediated the relationship between GA and birth weight, suggesting reverse causality in the relationship between GA and the methylome.

DISCUSSION

HDMAX2 outperformed existing approaches and revealed an unsuspected complexity of the potential causal relationships between exposure to MS and birth weight at the epigenome-wide level. HDMAX2 is applicable to a wide range of tissues and omic layers. https://doi.org/10.1289/EHP11559.

Early origins of metabolic and overall health in young adults: An outcome-wide analysis in a general cohort population

INTRODUCTION

Long-term consequences of impaired fetal growth are well documented for cardiometabolic outcomes. We propose an outcome-wide analysis of the association between birth weight (BW) and long-term health in a large contemporary adult cohort.

METHODS

The study included 73,315 participants under 60 years with a reliable BW from the French nationwide Constances cohort. Low and high BW (LBW/HBW) were defined as BW<10th and >90th of sex-specific percentiles. Associations between BW and outcomes were analyzed with a sex-stratified modified Poisson regression adjusted for the participant's age, maternal health history, geographical origins, and parents' occupation.

RESULTS

Mean BW (10^th -90^th percentile) was 3390 g (2800-4000) for men and 3247g (2680-3820) for women. In men, LBW was associated with (RR [CI95]): fasting glucose impairment (1.33 [1.16;1.52]); hypertriglyceridemia (1.27 [1.17;1.37]); high blood pressure (HBP) (1.15 [1.07;1.24]); non-alcoholic fatty liver disease NAFLD (1.13 [1.02;1.24]); high LDL-cholesterol (1.12 [1.05;1.21]); anxiety (1.12 [1.01;1.24]) and depression (1.09 [1.00;1.18]). HBW was associated with obesity (1.21 [1.08;1.35]). In women, LBW was associated with fasting glucose impairment (1.31 [1.12;1.54]); HBP (1.27 [1.16;1.4]); hypertriglyceridemia (1.20 [1.05;1.36]); anxiety (1.10 [1.03;1.17]); and asthma (1.09 [1;1.19}). HBW was associated with obesity (1.24 [1.13;1.36]) and NAFLD (1.20 [1.06;1.37). LBW and HBW were associated with a lesser likelihood of tertiary education attainment in both sexes. Participants' education level was a significant partial mediator of the association between LBW and outcomes.

CONCLUSION

Extreme BW is associated with long-term health. It should be considered in the personalized prevention of cardiometabolic, respiratory, and mental health conditions in adulthood, especially in socio-economically disadvantaged populations.

Associations of childhood adiposity with adult intima-media thickness and inflammation: a 20-year longitudinal population-based cohort

BACKGROUND

The associations between childhood adiposity and adult increased carotid intima-media thickness (cIMT) have been well established, which might be corroborated by the association between adiposity in children and inflammation in adults. However, longitudinal data regarding biological pathways associated with childhood adiposity are lacking.

METHODS

The current study included participants from the STANISLAS cohort who had adiposity measurements at age 5-18 years [ N  = 519, mean (SD) age, 13.0 (2.9) years; 46.4% male], and who were measured with cIMT, vascular-related and metabolic-related proteins at a median follow-up of 19 ± 2 years. BMI, waist-to-height ratio and waist circumference were converted to age-specific and sex-specific z -scores.

RESULTS

A minority of children were overweight/obese (16.2% overweight-BMI z -score >1; 1.3% obesity- z -score >2). Higher BMI, waist-height ratio and waist circumference in children were significantly associated with greater adult cIMT in univariable analysis, although not after adjusting for C-reactive protein. These associations were more pronounced in those with consistently high adiposity status from childhood to middle adulthood. Participants with higher adiposity during childhood (BMI or waist-height ratio) had higher levels of insulin-like growth factor-binding protein-1, protein-2, matrix metalloproteinase-3, osteopontin, hemoglobin and C-reactive protein in adulthood. Network analysis showed that IL-6, insulin-like growth factor-1 and fibronectin were the key proteins associated with childhood adiposity.

CONCLUSION

In a population-based cohort followed for 20 years, higher BMI or waist-to-height ratio in childhood was significantly associated with greater cIMT and enhanced levels of proteins reflective of inflammation, supporting the importance of inflammation as progressive atherosclerosis in childhood adiposity.

Parental feeding practices as potential moderating or mediating factors in the associations between children's early and later growth

BACKGROUND

Given inconsistent results in the literature, our objective was to examine the role of early parental feeding practices in children's growth.

METHODS

Analyses were based on 1245 children from the EDEN mother-child cohort. Parental feeding practices were assessed at the 2-year follow-up by using the Comprehensive Feeding Practices Questionnaire. International Obesity Task Force BMI z-scores were derived from weight and height assessed at 2, 4, 6, and 8 years. Associations between parental feeding practices and child BMI z-scores at 4, 6 and 8 years were assessed by multivariable linear regressions, notably adjusted for 2-year BMI z-score. Analyses were stratified by child sex when relevant. Moreover, interaction and mediation analyses were respectively performed to assess whether parental feeding practices could moderate or mediate the associations between early and later growth.

RESULTS

For a given BMI z-score at 2 years, parental restriction for weight at 2 years was positively associated with child BMI z-scores from 4 to 8 years (at 8 years: β [95% CI] = 0.09 [0.01; 0.16]). Among boys only, high use of food as a reward was positively associated with later BMI z-scores (at 8 years: β [95% CI] = 0.15 [0.03; 0.27]). Parental feeding practices were not moderating factors in the associations between early and later growth. Parental restriction for weight was a mediating factor in the associations between 2-year BMI z-score and BMI z-scores up to 8 years (mediation: 2.69% [0.27%; 5.11%] of the total effect at 8 years).

CONCLUSIONS

Restriction for weight reasons, often used by parents in response to the child's high appetite in infancy, appears to lie on the pathway between early and later BMI, but not restriction for health, suggesting that parental way of restricting the child's food intake matters.

Parental lifestyle patterns around pregnancy and risk of childhood obesity in four European birth cohort studies

BACKGROUND

A high prevalence of excess weight in children younger than 5 years suggests the involvement of early-life risk factors. The preconception and pregnancy periods are crucial stages for the implementation of interventions to prevent childhood obesity. Most studies so far have evaluated the effects of early-life factors separately, with only a few investigating the combined effect of parental lifestyle factors. Our objective was to fill the literature gap regarding parental lifestyle factors in the preconception and pregnancy periods and to study their association with the risk of overweight in children after the age of 5 years.

METHODS

We harmonised and interpreted data from four European mother-offspring cohorts (EDEN [comprising 1900 families], Elfe [comprising 18 000 families], Lifeways [comprising 1100 families], and Generation R [comprising 9500 families]). Written informed consent was obtained from parents of all involved children. Lifestyle factor data collected through questionnaires comprised parental smoking, BMI, gestational weight gain, diet, physical activity, and sedentary behaviour. We applied principal component analyses to identify multiple lifestyle patterns in preconception and pregnancy. Their association with child BMI z-score and risk of overweight (including obesity, overweight and obesity, as defined by the International Task Force reference) between the ages of 5 and 12 years were assessed using cohort-specific multivariable linear and logistic regression models (adjusted for confounders including parental age, education level, employment status, geographic origin, parity, and household income).

FINDINGS

Among the various lifestyle patterns identified in all cohorts, the two that better explained variance were high parental smoking plus low maternal diet quality or high maternal sedentary behaviour, and high parental BMI plus low gestational weight gain. Overall, we observed that patterns characterised by high parental BMI, smoking, low-quality diet, or sedentary lifestyle before or during pregnancy were associated with higher BMI z-scores and risk of overweight and obesity in children aged 5-12 years.

INTERPRETATION

Our data contribute to a better understanding of how parental lifestyle factors might be associated with the risk of childhood obesity. These findings are valuable to inform future family-based and multi-behavioural child obesity prevention strategies in early life.

FUNDING

European Union's Horizon 2020 under the ERA-NET Cofund action (reference 727565) and European Joint Programming Initiative "A Healthy Diet for a Healthy Life" (JPI HDHL, EndObesity).

Maternal Mental Health Care Matters: The Impact of Prenatal Depressive and Anxious Symptoms on Child Emotional and Behavioural Trajectories in the French EDEN Cohort

Few studies have investigated longitudinal trajectories of child socioemotional and behavioural development in relation to maternal prenatal mental health exposure or taken into consideration of the potential buffering effects of psychological intervention during pregnancy. Using data from 1135 mother-child dyads from the EDEN cohort from the general French population, Group-based trajectory modelling was used to model trajectories of behavioural and emotional characteristics measured at four timepoints via a parent-administered Strengths and Difficulties Questionnaire. Using propensity scores and inverse probability weighting to account for confounding factors, multinomial logistic regressions were used to quantify the associations with maternal symptoms of prenatal depression and anxiety. Stratified analyses were conducted by reporting psychologist and psychiatrist consultations during pregnancy. Compared to those without psychological problems, children of mothers with comorbid anxiety and depression retained a higher probability of following high and intermediate trajectories of emotional problems and a high trajectory of conduct problems throughout childhood. This increased risk was not present in the children of mothers who sought support through a prenatal psychologist or psychiatrist consultation. This article adds to a body of evidence underlining the importance of mental health care for expecting mothers.

Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies

BACKGROUND

Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence.

METHODS AND FINDINGS

We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries.

CONCLUSIONS

This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.

Prospective associations of lifestyle patterns in early childhood with socio-emotional and behavioural development and BMI: An outcome-wide analysis of the EDEN mother-child cohort

BACKGROUND

Children's energy balance-related behaviours (EBRB), comprising diet, screen time, physical activity, and sleep, combine into "lifestyle patterns", which may exert a synergistic effect on health. To date, studies investigating this synergy have primarily focused on obesity risk, without addressing other facets of health.

OBJECTIVES

To examine the prospective associations of preschoolers' lifestyle patterns with socio-emotional, behavioural, and body mass index (BMI) outcomes at 8 years.

METHODS

Participants were 876 children from the EDEN mother-child cohort. Three lifestyle patterns (unhealthy, healthy, and mixed) were previously identified at age 5, separately in boys and girls. At age 8, height and weight measures generated BMI z-scores while social-emotional and behavioural development was assessed by parents using the Strengths and Difficulties Questionnaire (SDQ). Drawing from the outcome-wide approach, sex- and outcome-specific adjusted linear regressions were fitted.

RESULTS

Boys' adherence to a healthy lifestyle pattern (combining a nutrient-dense diet and limited screen time) at 5 years was positively associated with prosocial behaviours (β = 0.14; 95% confidence interval [CI] 0.01, 0.26) and inversely related to hyperactivity-inattention symptoms (β = -0.12; 95% CI -0.23, -0.01) at 8 years. Girls' mixed lifestyle pattern (sugar or artificially sweetened beverages, high screen, physical activity and low sleep times) was associated with prosocial behaviours (β = 0.12; 95% CI 0.01, 0.23). There was no evidence of associations between lifestyle patterns and BMI z-scores.

CONCLUSIONS

Findings suggest synergistic benefits of engaging in a combination of optimal EBRBs, especially in boys, and support intervention efforts at preschool age to enhance some dimensions of their later socio-emotional and behavioural development.

The effectiveness of interventions during the first 1,000 days to improve energy balance-related behaviors or prevent overweight/obesity in children from socio-economically disadvantaged families of high-income countries: a systematic review

This narrative systematic review examined effectiveness of interventions during pregnancy and up to 2 years of age in improving energy balance-related behaviors or prevent overweight/obesity in children from families experiencing socio-economic disadvantage. We identified 24 interventions, from 33 articles, since 1990. Overall, despite their heterogeneity and variability in internal and external validity, there was some evidence of beneficial impact of interventions on obesity risk (4/15), and associated behaviors, e.g.: breastfeeding (9/18), responsive feeding (11/16), diet (7/8), sedentary (1/3) and movement (4/7) behaviors, and sleep (1/2). The most effective interventions aimed at promoting breastfeeding commenced antenatally; this was similar for the prevention of obesity, provided the intervention continued for at least 2 years postnatally and was multi-behavioral. Effective interventions were more likely to target first-time mothers and involve professional delivery agents, multidisciplinary teams and peer groups. Among ethnic/racial minorities, interventions delivered by lay agents had some impact on dietary behavior but not weight outcomes. Co-creation with stakeholders, including parents, and adherence to theoretical frameworks were additional ingredients for more pragmatic, inclusive, non-judgmental, and effective programs. The growing body of evidence on obesity prevention interventions targeting families experiencing socio-economic disadvantage is promising for reducing early inequalities in obesity risk.

Exposure to natural environments during pregnancy and birth outcomes in 11 European birth cohorts

Research suggests that maternal exposure to natural environments (i.e., green and blue spaces) promotes healthy fetal growth. However, the available evidence is heterogeneous across regions, with very few studies on the effects of blue spaces. This study evaluated associations between maternal exposure to natural environments and birth outcomes in 11 birth cohorts across nine European countries. This study, part of the LifeCycle project, was based on a total sample size of 69,683 newborns with harmonised data. For each participant, we calculated seven indicators of residential exposure to natural environments: surrounding greenspace in 100m, 300m, and 500m using Normalised Difference Vegetation Index (NDVI) buffers, distance to the nearest green space, accessibility to green space, distance to the nearest blue space, and accessibility to blue space. Measures of birth weight and small for gestational age (SGA) were extracted from hospital records. We used pooled linear and logistic regression models to estimate associations between exposure to the natural environment and birth outcomes, controlling for the relevant covariates. We evaluated the potential effect modification by socioeconomic status (SES) and region of Europe and the influence of ambient air pollution on the associations. In the pooled analyses, residential surrounding greenspace in 100m, 300m, and 500m buffer was associated with increased birth weight and lower odds for SGA. Higher residential distance to green space was associated with lower birth weight and higher odds for SGA. We observed close to null associations for accessibility to green space and exposure to blue space. We found stronger estimated magnitudes for those participants with lower educational levels, from more deprived areas, and living in the northern European region. Our associations did not change notably after adjustment for air pollution. These findings may support implementing policies to promote natural environments in our cities, starting in more deprived areas.

A meta-analysis of pre-pregnancy maternal body mass index and placental DNA methylation identifies 27 CpG sites with implications for mother-child health

Higher maternal pre-pregnancy body mass index (ppBMI) is associated with increased neonatal morbidity, as well as with pregnancy complications and metabolic outcomes in offspring later in life. The placenta is a key organ in fetal development and has been proposed to act as a mediator between the mother and different health outcomes in children. The overall aim of the present work is to investigate the association of ppBMI with epigenome-wide placental DNA methylation (DNAm) in 10 studies from the PACE consortium, amounting to 2631 mother-child pairs. We identify 27 CpG sites at which we observe placental DNAm variations of up to 2.0% per 10 ppBMI-unit. The CpGs that are differentially methylated in placenta do not overlap with CpGs identified in previous studies in cord blood DNAm related to ppBMI. Many of the identified CpGs are located in open sea regions, are often close to obesity-related genes such as GPX1 and LGR4 and altogether, are enriched in cancer and oxidative stress pathways. Our findings suggest that placental DNAm could be one of the mechanisms by which maternal obesity is associated with metabolic health outcomes in newborns and children, although further studies will be needed in order to corroborate these findings.

Applied causal inference methods for sequential mediators

BACKGROUND

Mediation analysis aims at estimating to what extent the effect of an exposure on an outcome is explained by a set of mediators on the causal pathway between the exposure and the outcome. The total effect of the exposure on the outcome can be decomposed into an indirect effect, i.e. the effect explained by the mediators jointly, and a direct effect, i.e. the effect unexplained by the mediators. However finer decompositions are possible in presence of independent or sequential mediators.

METHODS

We review four statistical methods to analyse multiple sequential mediators, the inverse odds ratio weighting approach, the inverse probability weighting approach, the imputation approach and the extended imputation approach. These approaches are compared and implemented using a case-study with the aim to investigate the mediating role of adverse reproductive outcomes and infant respiratory infections in the effect of maternal pregnancy mental health on infant wheezing in the Ninfea birth cohort.

RESULTS

Using the inverse odds ratio weighting approach, the direct effect of maternal depression or anxiety in pregnancy is equal to a 59% (95% CI: 27%,94%) increased prevalence of infant wheezing and the mediated effect through adverse reproductive outcomes is equal to a 3% (95% CI: -6%,12%) increased prevalence of infant wheezing. When including infant lower respiratory infections in the mediation pathway, the direct effect decreases to 57% (95% CI: 25%,92%) and the indirect effect increases to 5% (95% CI: -5%,15%). The estimates of the effects obtained using the weighting and the imputation approaches are similar. The extended imputation approach suggests that the small joint indirect effect through adverse reproductive outcomes and lower respiratory infections is due entirely to the contribution of infant lower respiratory infections, and not to an increased prevalence of adverse reproductive outcomes.

CONCLUSIONS

The four methods revealed similar results of small mediating role of adverse reproductive outcomes and early respiratory tract infections in the effect of maternal pregnancy mental health on infant wheezing. The choice of the method depends on what is the effect of main interest, the type of the variables involved in the analysis (binary, categorical, count or continuous) and the confidence in specifying the models for the exposure, the mediators and the outcome.

Multi-omics signatures of the human early life exposome

Environmental exposures during early life play a critical role in life-course health, yet the molecular phenotypes underlying environmental effects on health are poorly understood. In the Human Early Life Exposome (HELIX) project, a multi-centre cohort of 1301 mother-child pairs, we associate individual exposomes consisting of >100 chemical, outdoor, social and lifestyle exposures assessed in pregnancy and childhood, with multi-omics profiles (methylome, transcriptome, proteins and metabolites) in childhood. We identify 1170 associations, 249 in pregnancy and 921 in childhood, which reveal potential biological responses and sources of exposure. Pregnancy exposures, including maternal smoking, cadmium and molybdenum, are predominantly associated with child DNA methylation changes. In contrast, childhood exposures are associated with features across all omics layers, most frequently the serum metabolome, revealing signatures for diet, toxic chemical compounds, essential trace elements, and weather conditions, among others. Our comprehensive and unique resource of all associations ( https://helixomics.isglobal.org/ ) will serve to guide future investigation into the biological imprints of the early life exposome.

Cord blood leptin level and a common variant of its receptor as determinants of the BMI trajectory: The EDEN mother-child cohort

BACKGROUND

Cord blood leptin is an indicator of neonatal fat mass and could shape postnatal adiposity trajectories. Investigating genetic polymorphisms of the leptin receptor gene (LEPR) could help understand the mechanisms involved.

OBJECTIVES

We aimed to investigate the association of cord blood leptin level and the LEPR rs9436303 polymorphism, with body mass index (BMI) at adiposity peak (AP) and age at adiposity rebound (AR).

METHODS

In the EDEN cohort, BMI at AP and age at AR were estimated with polynomial mixed models, for 1713 and 1415 children, respectively. Multivariable linear regression models allowed for examining the associations of cord blood leptin level and LEPR rs9436303 genotype with BMI at AP and age at AR adjusted for potential confounders including birth size groups. We also tested interactions between cord blood leptin level and rs9436303 genotype.

RESULTS

Increased leptin level was associated with reduced BMI at AP and early age at AR (comparing the highest quintile of leptin level to the others). Rs9436303 G-allele carriage was associated with increased BMI at AP and later age at AR but did not modulate the association with leptin level.

CONCLUSION

These results illustrate the role of early life body composition and the intrauterine environment in the programming of adiposity in childhood.

Maternal pre-pregnancy obesity and offspring hyperactivity-inattention symptoms at 5 years in preterm and term children: a multi-cohort analysis

The objective of this study was to determine the relationship between maternal pre-pregnancy body mass index (BMI) and child hyperactivity-inattention symptoms (HIS) at 5 years, including preterm and term-born children, and to determine whether this association varied with gestational age. Maternal pre-pregnancy BMI and offspring HIS were assessed in 10,898 participants born ≥ 33 weeks of gestation from the ELFE cohort and 2646 children born between 23 and 34 weeks from the EPIPAGE 2 cohort. Reported pre-pregnancy weight (kg) and measured height (m) were collected from mothers at inclusion and used to classify BMI (kg/m²). Child HIS were evaluated using the Strengths and Difficulties Questionnaire around 5 years of age. Logistic regression estimated odds ratios (OR) of a high HIS score (≥ 90th percentile) in the ELFE cohort and generalized estimated equations were used in EPIPAGE 2 to account for non-independence of multiple births. As a negative control, paternal BMI was also considered as an exposure of interest in sensitivity analyses. Maternal pre-pregnancy obesity and overweight were associated with child HIS at 5 years in ELFE (adjusted OR [aOR] for obesity 1.27 [1.06, 1.53]; overweight aOR 1.16 [1.00, 1.36]) and pre-pregnancy obesity was associated with high HIS scores in preterm infants of EPIPAGE 2 (aOR 1.48 [1.06, 2.08]). In ELFE, the magnitude of the association increased with decreasing gestational age (interaction p = 0.02). High maternal pre-pregnancy BMI is associated with greater likelihood of high HIS scores in both at-term and preterm children at 5 years of age.

Early delivery following chronic and acute ambient temperature exposure: a comprehensive survival approach

Background

Ambient temperature, particularly heat, is increasingly acknowledged as a trigger for preterm delivery but study designs have been limited and results mixed. We aimed to comprehensively evaluate the association between ambient temperature throughout pregnancy and preterm delivery.

Methods

We estimated daily temperature throughout pregnancy using a cutting-edge spatiotemporal model for 5347 live singleton births from three prospective cohorts in France, 2002–2018. We performed Cox regression (survival analysis) with distributed lags to evaluate time-varying associations with preterm birth simultaneously controlling for exposure during the first 26 weeks and last 30 days of pregnancy. We examined weekly mean, daytime, night-time and variability of temperature, and heatwaves accounting for adaptation to location and season.

Results

Preterm birth risk was higher following cold (5th vs 50th percentile of mean temperature) 7–9 weeks after conception [relative risk (RR): 1.3, 95% CI: 1.0–1.6 for 2°C vs 11.6°C] and 10–4 days before delivery (RR: 1.6, 95% CI: 1.1–2.1 for 1.2°C vs 12.1°C). Night-time heat (95th vs 50th percentile of minimum temperature; 15.7°C vs 7.4°C) increased risk when exposure occurred within 5 weeks of conception (RR: 2.0, 95% CI: 1.05–3.8) or 20–26 weeks after conception (RR: 2.9, 95% CI: 1.2–6.8). Overall and daytime heat (high mean and maximum temperature) showed consistent effects. We found no clear associations with temperature variability or heatwave indicators, suggesting they may be less relevant for preterm birth.

Conclusions

In a temperate climate, night-time heat and chronic and acute cold exposures were associated with increased risk of preterm birth. These results suggest night-time heat as a relevant indicator. In the context of rising temperatures and more frequent weather hazards, these results should inform public health policies to reduce the growing burden of preterm births.

Maternal blood pressure associates with placental DNA methylation both directly and through alterations in cell-type composition

BACKGROUND

Maternal blood pressure levels reflect cardiovascular adaptation to pregnancy and proper maternal-fetal exchanges through the placenta and are very sensitive to numerous environmental stressors. Maternal hypertension during pregnancy has been associated with impaired placental functions and with an increased risk for children to suffer from cardiovascular and respiratory diseases later on. Investigating changes in placental DNA methylation levels and cell-type composition in association with maternal blood pressure could help elucidate its relationships with placental and fetal development.

METHODS

Taking advantage of a large cohort of 666 participants, we investigated the association between epigenome-wide DNA methylation patterns in the placenta, measured using the Infinium HumanMethylation450 BeadChip, placental cell-type composition, estimated in silico, and repeated measurements of maternal steady and pulsatile blood pressure indicators during pregnancy.

RESULTS

At the site-specific level, no significant association was found between maternal blood pressure and DNA methylation levels after correction for multiple testing (false discovery rate < 0.05), but 5 out of 24 previously found CpG associations were replicated (p-value < 0.05). At the regional level, our analyses highlighted 64 differentially methylated regions significantly associated with at least one blood pressure component, including 35 regions associated with mean arterial pressure levels during late pregnancy. These regions were found enriched for genes implicated in lung development and diseases. Further mediation analyses show that a significant part of the association between steady blood pressure-but not pulsatile pressure-and placental methylation can be explained by alterations in placental cell-type composition. In particular, elevated blood pressure levels are associated with a decrease in the ratio between mesenchymal stromal cells and syncytiotrophoblasts, even in the absence of preeclampsia.

CONCLUSIONS

This study provides the first evidence that the association between maternal steady blood pressure during pregnancy and placental DNA methylation is both direct and partly explained by changes in cell-type composition. These results could hint at molecular mechanisms linking maternal hypertension to lung development and early origins of childhood respiratory problems and at the importance of controlling maternal blood pressure during pregnancy.

Predictors of maternal dietary quality and dietary inflammation during pregnancy: An individual participant data meta-analysis of seven European cohorts from the ALPHABET consortium

BACKGROUND & AIMS

Maternal diet during pregnancy is a modifiable behaviour which plays an important role in maternal, neonatal and child health outcomes. Thus, knowledge of predictors of dietary quality and dietary inflammatory potential in European countries may contribute to developing maternal diet-related public health policies that target specific at-risk populations in Europe.

METHODS

We used harmonised data from >26,000 pregnant women enrolled in the ALSPAC, EDEN, Generation R, Lifeways, REPRO_PL, ROLO and SWS cohorts, as part of the ALPHABET consortium. Maternal dietary quality and inflammatory potential were assessed using the Dietary Approaches to Stop Hypertension (DASH) and the energy-adjusted Dietary Inflammatory Index (E-DII). We conducted an individual participant data meta-analysis to investigate the maternal sociodemographic, health and behavioural predictors of maternal diet before and during pregnancy.

RESULTS

DASH and E-DII scores were moderately correlated: from -0.63 (95% CI: -0.66, -0.59) to -0.48 (95% CI: -0.49, -0.47) across cohorts. Higher maternal age, education, household income, and physical activity during pregnancy were associated with a better dietary quality and a more anti-inflammatory diet. Conversely, multiparity and smoking during pregnancy were associated with a poorer dietary quality and a more proinflammatory diet. Women with obesity had a poorer pregnancy dietary quality than women with a normal body mass index range.

CONCLUSIONS

The results will help identify population subgroups who may benefit from targeted public health strategies and interventions aimed at improving women's dietary quality during pregnancy.

Preschool language and visuospatial skills respectively predict multiplication and addition/subtraction skills in middle school children

A converging body of evidence from neuroimaging, behavioral and neuropsychology studies suggests that different arithmetic operations rely on distinct neuro-cognitive processes: while addition and subtraction may rely more on visuospatial reasoning, multiplication would depend more on verbal abilities. In this paper, we tested this hypothesis in a longitudinal study measuring language and visuospatial skills in 358 preschoolers, and testing their mental calculation skills at the beginning of middle school. Language skills at 5.5 years significantly predicted multiplication, but not addition nor subtraction scores at 11.5 years. Conversely, early visuospatial skills predicted addition and subtraction, but not multiplication scores. These results provide strong support for the existence of a double dissociation in mental arithmetic operations, and demonstrate the existence of long-lasting links between language/visuospatial skills and specific calculation abilities. Using structural equation modelling, we analyzed longitudinal data from 358 children. Language skills in preschool significantly predicted multiplication, but not addition nor subtraction scores in middle school. The reverse was true for preschool visuo-spatial skills. Importantly, this pattern remained unchanged when we controlled addition and multiplication operations for overall difficulty and for the magnitude of the operands. These results provide strong support for the existence of a double dissociation in mental arithmetic operations. This article is protected by copyright. All rights reserved.

Short- and medium-term air pollution exposure, plasmatic protein levels and blood pressure in children

Exposure to air pollution influences children's health, however, the biological mechanisms underlying these effects are not completely elucidated. We investigated the association between short- and medium-term outdoor air pollution exposure with protein profiles and their link with blood pressure in 1170 HELIX children aged 6-11 years. Different air pollutants (NO₂, PM₁₀, PM_2.5, and PM_2.5abs) were estimated based on residential and school addresses at three different windows of exposure (1-day, 1-week, and 1-year before clinical and molecular assessment). Thirty-six proteins, including adipokines, cytokines, or apolipoproteins, were measured in children's plasma using Luminex. Systolic and diastolic blood pressure (SBP and DBP) were measured following a standardized protocol. We performed an association study for each air pollutant at each location and time window and each outcome, adjusting for potential confounders. After correcting for multiple-testing, hepatocyte growth factor (HGF) and interleukin 8 (IL8) levels were positively associated with 1-week home exposure to some of the pollutants (NO₂, PM₁₀, or PM_2.5). NO₂ 1-week home exposure was also related to higher SBP. The mediation study suggested that HGF could explain 19% of the short-term effect of NO₂ on blood pressure, but other study designs are needed to prove the causal directionality between HGF and blood pressure.