Cohort Profile: The European Longitudinal Study of Pregnancy and Childhood (ELSPAC) in the Czech Republic

Prenatal exposure to air pollution and maternal depression: Combined effects on brain aging and mental health in young adulthood

INTRODUCTION

Both maternal depression problems during pregnancy and prenatal exposure to air pollution have been associated with changes in the brain as well as worse mood and anxiety in the offspring in adulthood. However, it is not clear whether these effects are independent or whether and how they might interact and impact the brain age and mental health of the young adult offspring.

METHODS

A total of 202 mother-child dyads from a prenatal birth cohort were assessed for maternal depression during pregnancy through self-report questionnaires administered in the early 90s, exposure to air pollutants (Sulfur dioxide [SO2], nitrogen oxides [NOx], and suspended particle matter [SPM]) during each trimester based on maternal address and air quality data, mental health of the young adult offspring (28-30 years of age; 52% men, all of European ancestry) using self-report questionnaires for depression (Beck Depression Inventory), mood dysregulation (Profile of Mood States), anxiety (State-Trait Anxiety Inventory), and psychotic symptoms (Schizotypal Personality Questionnaire), and brain age, estimated from structural magnetic resonance imaging (MRI) and previously published neuroanatomical age prediction model using cortical thickness maps. The brain age gap estimate (BrainAGE) was computed by subtracting structural brain age from chronological age. Trajectories of exposure to air pollution during pregnancy were assessed using Growth Mixture Modeling. The interactions of prenatal depression and prenatal exposure to air pollutants on adult mental health and BrainAGE were assessed using hierarchical linear regression.

RESULTS

We revealed two distinct trajectories of exposure to air pollution during pregnancy: "early exposure," characterized by high exposure during the first trimester, followed by a steady decrease, and "late exposure," characterized by low exposure during the first trimester, followed by a steady increase in the exposure during the subsequent trimesters. Maternal depression during the first half of pregnancy interacted with NOX exposure trajectory, predicting mood dysregulation and schizotypal symptoms in young adults. In addition, maternal depression during the second half of pregnancy interacted with both NOx and SO2 exposure trajectories, respectively, and predicted BrainAGE in young adults. In those with early exposure to NOx, maternal depression during pregnancy was associated with worse mental health and accelerated brain aging in young adulthood. In contrast, in those with early exposure to SO2, maternal depression during pregnancy was associated with slower brain aging in young adulthood.

CONCLUSIONS

Our findings provide the first evidence of the combined effects of prenatal exposure to air pollution and maternal depression on mental health outcomes and brain age in young adult offspring. Moreover, they point out the importance of the timing and trajectory of the exposure during prenatal development.

Prenatal exposure to alcohol and its impact on reward processing and substance use in adulthood

Heavy maternal alcohol drinking during pregnancy has been associated with altered neurodevelopment in the child but the effects of low-dose alcohol drinking are less clear and any potential safe level of alcohol use during pregnancy is not known. We evaluated the effects of prenatal alcohol on reward-related behavior and substance use in young adulthood and the potential sex differences therein. Participants were members of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) prenatal birth cohort who participated in its neuroimaging follow-up in young adulthood. A total of 191 participants (28-30 years; 51% men) had complete data on prenatal exposure to alcohol, current substance use, and fMRI data from young adulthood. Maternal alcohol drinking was assessed during mid-pregnancy and pre-conception. Brain response to reward anticipation and reward feedback was measured using the Monetary Incentive Delay task and substance use in young adulthood was assessed using a self-report questionnaire. We showed that even a moderate exposure to alcohol in mid-pregnancy but not pre-conception was associated with robust effects on brain response to reward feedback (six frontal, one parietal, one temporal, and one occipital cluster) and with greater cannabis use in both men and women 30 years later. Moreover, mid-pregnancy but not pre-conception exposure to alcohol was associated with greater cannabis use in young adulthood and these effects were independent of maternal education and maternal depression during pregnancy. Further, the extent of cannabis use in the late 20 s was predicted by the brain response to reward feedback in three out of the nine prenatal alcohol-related clusters and these effects were independent of current alcohol use. Sex differences in the brain response to reward outcome emerged only during the no loss vs. loss contrast. Young adult men exposed to alcohol prenatally had significantly larger brain response to no loss vs. loss in the putamen and occipital region than women exposed to prenatal alcohol. Therefore, we conclude that even moderate exposure to alcohol prenatally has long-lasting effects on brain function during reward processing and risk of cannabis use in young adulthood.

Altered Transcriptome Response in PBMCs of Czech Adults Linked to Multiple PFAS Exposure: B Cell Development as a Target of PFAS Immunotoxicity

While the immunomodulation effects of per- and polyfluoroalkyl substances (PFASs) are described on the level of clinical signs in epidemiological studies (e.g., suppressed antibody response after vaccination), the underlying mechanism has still not been fully elucidated. To reveal mechanisms of PFAS exposure on immunity, we investigated the genome-wide transcriptomic changes of peripheral blood mononuclear cells (PBMCs) responding to PFAS exposure (specifically, exposure to PFPA, PFOA, PFNA, PFDA, PFUnDA, PFHxS, and PFOS). Blood samples and the chemical load in the blood were analyzed under the cross-sectional CELSPAC: Young Adults study. The overall aim of the study was to identify sensitive gene sets and cellular pathways conserved for multiple PFAS chemicals. Transcriptome networks related to adaptive immunity were perturbed by multiple PFAS exposure (i.e., blood levels of at least four PFASs). Specifically, processes tightly connected with late B cell development, such as B cell receptor signaling, germinal center reactions, and plasma cell development, were shown to be affected. Our comprehensive transcriptome analysis identified the disruption of B cell development, specifically the impact on the maturation of antibody-secreting cells, as a potential mechanism underlying PFAS immunotoxicity.

Developing non-response weights to account for attrition-related bias in a longitudinal pregnancy cohort

BACKGROUND

Prospective cohorts may be vulnerable to bias due to attrition. Inverse probability weights have been proposed as a method to help mitigate this bias. The current study used the "All Our Families" longitudinal pregnancy cohort of 3351 maternal-infant pairs and aimed to develop inverse probability weights using logistic regression models to predict study continuation versus drop-out from baseline to the three-year data collection wave.

METHODS

Two methods of variable selection took place. One method was a knowledge-based a priori variable selection approach, while the second used Least Absolute Shrinkage and Selection Operator (LASSO). The ability of each model to predict continuing participation through discrimination and calibration for both approaches were evaluated by examining area under the receiver operating curve (AUROC) and calibration plots, respectively. Stabilized inverse probability weights were generated using predicted probabilities. Weight performance was assessed using standardized differences of baseline characteristics for those who continue in study and those that do not, with and without weights (unadjusted estimates).

RESULTS

The a priori and LASSO variable selection method prediction models had good and fair discrimination with AUROC of 0.69 (95% Confidence Interval [CI]: 0.67-0.71) and 0.73 (95% CI: 0.71-0.75), respectively. Calibration plots and non-significant Hosmer-Lemeshow Goodness of Fit Tests indicated that both the a priori (p = 0.329) and LASSO model (p = 0.242) were well-calibrated. Unweighted results indicated large (> 10%) standardized differences in 15 demographic variables (range: 11 - 29%), when comparing those who continued in the study with those that did not. Weights derived from the a priori and LASSO models reduced standardized differences relative to unadjusted estimates, with the largest differences of 13% and 5%, respectively. Additionally, when applying the same LASSO variable selection method to develop weights in future data collection waves, standardized differences remained below 10% for each demographic variable.

CONCLUSION

The LASSO variable selection approach produced robust weights that addressed non-response bias more than the knowledge-driven approach. These weights can be applied to analyses across multiple longitudinal waves of data collection to reduce bias.

Longitudinal study of epigenetic aging and its relationship with brain aging and cognitive skills in young adulthood

Introduction

The proportion of older adults within society is sharply increasing and a better understanding of how we age starts to be critical. However, given the paucity of longitudinal studies with both neuroimaging and epigenetic data, it remains largely unknown whether the speed of the epigenetic clock changes over the life course and whether any such changes are proportional to changes in brain aging and cognitive skills. To fill these knowledge gaps, we conducted a longitudinal study of a prenatal birth cohort, studied epigenetic aging across adolescence and young adulthood, and evaluated its relationship with brain aging and cognitive outcomes.

Methods

DNA methylation was assessed using the Illumina EPIC Platform in adolescence, early and late 20 s, DNA methylation age was estimated using Horvath's epigenetic clock, and epigenetic age gap (EpiAGE) was calculated as DNA methylation age residualized for batch, chronological age and the proportion of epithelial cells. Structural magnetic resonance imaging (MRI) was acquired in both the early 20 s and late 20 s using the same 3T Prisma MRI scanner and brain age was calculated using the Neuroanatomical Age Prediction using R (NAPR) platform. Cognitive skills were assessed using the Wechsler Adult Intelligence Scale (WAIS) in the late 20 s.

Results

The EpiAGE in adolescence, the early 20 s, and the late 20 s were positively correlated (r = 0.34-0.47), suggesting that EpiAGE is a relatively stable characteristic of an individual. Further, a faster pace of aging between the measurements was positively correlated with EpiAGE at the end of the period (r = 0.48-0.77) but negatively correlated with EpiAGE at the earlier time point (r = -0.42 to -0.55), suggesting a compensatory mechanism where late matures might be catching up with the early matures. Finally, higher positive EpiAGE showed small (Adj R2 = 0.03) but significant relationships with a higher positive brain age gap in all participants and lower full-scale IQ in young adult women in the late 20 s.

Discussion

We conclude that the EpiAGE is a relatively stable characteristic of an individual across adolescence and early adulthood, but that it shows only a small relationship with accelerated brain aging and a women-specific relationship with worse performance IQ.

Enrichment of human nasopharyngeal bacteriome with bacteria from dust after short-term exposure to indoor environment: a pilot study

BACKGROUND

Indoor dust particles are an everyday source of human exposure to microorganisms and their inhalation may directly affect the microbiota of the respiratory tract. We aimed to characterize the changes in human nasopharyngeal bacteriome after short-term exposure to indoor (workplace) environments.

METHODS

In this pilot study, nasopharyngeal swabs were taken from 22 participants in the morning and after 8 h of their presence at the workplace. At the same time points, indoor dust samples were collected from the participants' households (16 from flats and 6 from houses) and workplaces (8 from a maternity hospital - NEO, 6 from a pediatric hospital - ENT, and 8 from a research center - RCX). 16S rRNA sequencing analysis was performed on these human and environmental matrices.

RESULTS

Staphylococcus and Corynebacterium were the most abundant genera in both indoor dust and nasopharyngeal samples. The analysis indicated lower bacterial diversity in indoor dust samples from flats compared to houses, NEO, ENT, and RCX (p < 0.05). Participants working in the NEO had the highest nasopharyngeal bacterial diversity of all groups (p < 0.05). After 8 h of exposure to the workplace environment, enrichment of the nasopharynx with several new bacterial genera present in the indoor dust was observed in 76% of study participants; however, no significant changes were observed at the level of the nasopharyngeal bacterial diversity (p > 0.05, Shannon index). These "enriching" bacterial genera overlapped between the hospital workplaces - NEO and ENT but differed from those in the research center - RCX.

CONCLUSIONS

The results suggest that although the composition of nasopharyngeal bacteriome is relatively stable during the day. Short-term exposure to the indoor environment can result in the enrichment of the nasopharynx with bacterial DNA from indoor dust; the bacterial composition, however, varies by the indoor workplace environment.

Association of Maternal Depression During Pregnancy and Recent Stress With Brain Age Among Adult Offspring

IMPORTANCE

Maternal mental health problems during pregnancy are associated with altered neurodevelopment in offspring, but the long-term relationship between these prenatal risk factors and offspring brain structure in adulthood remains incompletely understood due to a paucity of longitudinal studies.

OBJECTIVE

To evaluate the association between exposure to maternal depression in utero and offspring brain age in the third decade of life, and to evaluate recent stressful life events as potential moderators of this association.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined the 30-year follow-up of a Czech prenatal birth cohort with a within-participant design neuroimaging component in young adulthood conducted from 1991 to 2022. Participants from the European Longitudinal Study of Pregnancy and Childhood prenatal birth cohort were recruited for 2 magnetic resonance imaging (MRI) follow-ups, one between ages 23 and 24 years (early 20s) and another between ages 28 and 30 years (late 20s).

EXPOSURES

Maternal depression during pregnancy; stressful life events in the past year experienced by the young adult offspring.

MAIN OUTCOMES AND MEASURES

Gap between estimated neuroanatomical vs chronological age at MRI scan (brain age gap estimation [BrainAGE]) calculated once in participants' early 20s and once in their late 20s, and pace of aging calculated as the differences between BrainAGE at the 2 MRI sessions in young adulthood.

RESULTS

A total of 260 individuals participated in the second neuroimaging follow-up (mean [SD] age, 29.5 [0.6] years; 135 [52%] male); MRI data for both time points and a history of maternal depression were available for 110 participants (mean [SD] age, 29.3 [0.6] years; 56 [51%] male). BrainAGE in participants' early 20s was correlated with BrainAGE in their late 20s (r = 0.7, P < .001), and a previously observed association between maternal depression during pregnancy and BrainAGE in their early 20s persisted in their late 20s (adjusted R2 = 0.04; P = .04). However, no association emerged between maternal depression during pregnancy and the pace of aging between the 2 MRI sessions. The stability of the associations between maternal depression during pregnancy and BrainAGE was also supported by the lack of interactions with recent stress. In contrast, more recent stress was associated with greater pace of aging between the 2 MRI sessions, independent of maternal depression (adjusted R2 = 0.09; P = .01).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that maternal depression and recent stress may have independent associations with brain age and the pace of aging, respectively, in young adulthood. Prevention and treatment of depression in pregnant mothers may have long-term implications for offspring brain development.

Polymorphisms in genes expressed during amelogenesis and their association with dental caries: a case–control study

Objectives

Dental caries is a widespread multifactorial disease, caused by the demineralization of hard dental tissues. Susceptibility to dental caries is partially genetically conditioned; this study was aimed at finding an association of selected single nucleotide polymorphisms (SNPs) in genes encoding proteins involved in amelogenesis with this disease in children.

Materials and methods

In this case–control study, 15 SNPs in ALOX15, AMBN, AMELX, KLK4, TFIP11, and TUFT1 genes were analyzed in 150 children with primary dentition and 611 children with permanent teeth with/without dental caries from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) cohort.

Results

Dental caries in primary dentition was associated with SNPs in AMELX (rs17878486) and KLK4 (rs198968, rs2242670), and dental caries in permanent dentition with SNPs in AMELX (rs17878486) and KLK4 (rs2235091, rs2242670, rs2978642), (p ≤ 0.05). No significant differences between cases and controls were observed in the allele or genotype frequencies of any of the selected SNPs in ALOX15, AMBN, TFIP11, and TUFT1 genes (p > 0.05). Some KLK4 haplotypes were associated with dental caries in permanent dentition (p ≤ 0.05).

Conclusions

Based on this study, we found that although the SNPs in AMELX and KLK4 are localized in intronic regions and their functional significance has not yet been determined, they are associated with susceptibility to dental caries in children.

Clinical relevance

AMELX and KLK4 variants could be considered in the risk assessment of dental caries, especially in permanent dentition, in the European Caucasian population.

Infections and Pregnancy: Effects on Maternal and Child Health

Pregnancy causes physiological and immunological adaptations that allow the mother and fetus to communicate with precision in order to promote a healthy pregnancy. At the same time, these adaptations may make pregnant women more susceptible to infections, resulting in a variety of pregnancy complications; those pathogens may also be vertically transmitted to the fetus, resulting in adverse pregnancy outcomes. Even though the placenta has developed a robust microbial defense to restrict vertical microbial transmission, certain microbial pathogens have evolved mechanisms to avoid the placental barrier and cause congenital diseases. Recent mechanistic studies have begun to uncover the striking role of the maternal microbiota in pregnancy outcomes. In this review, we discuss how microbial pathogens overcome the placental barrier to cause congenital diseases. A better understanding of the placental control of fetal infection should provide new insights into future translational research.

Harmonization of Human Biomonitoring Studies in Europe: Characteristics of the HBM4EU-Aligned Studies Participants

Human biomonitoring has become a pivotal tool for supporting chemicals' policies. It provides information on real-life human exposures and is increasingly used to prioritize chemicals of health concern and to evaluate the success of chemical policies. Europe has launched the ambitious REACH program in 2007 to improve the protection of human health and the environment. In October 2020 the EU commission published its new chemicals strategy for sustainability towards a toxic-free environment. The European Parliament called upon the commission to collect human biomonitoring data to support chemical's risk assessment and risk management. This manuscript describes the organization of the first HBM4EU-aligned studies that obtain comparable human biomonitoring (HBM) data of European citizens to monitor their internal exposure to environmental chemicals. The HBM4EU-aligned studies build on existing HBM capacity in Europe by aligning national or regional HBM studies. The HBM4EU-aligned studies focus on three age groups: children, teenagers, and adults. The participants are recruited between 2014 and 2021 in 11 to 12 primary sampling units that are geographically distributed across Europe. Urine samples are collected in all age groups, and blood samples are collected in children and teenagers. Auxiliary information on socio-demographics, lifestyle, health status, environment, and diet is collected using questionnaires. In total, biological samples from 3137 children aged 6-12 years are collected for the analysis of biomarkers for phthalates, HEXAMOLL® DINCH, and flame retardants. Samples from 2950 teenagers aged 12-18 years are collected for the analysis of biomarkers for phthalates, Hexamoll® DINCH, and per- and polyfluoroalkyl substances (PFASs), and samples from 3522 adults aged 20-39 years are collected for the analysis of cadmium, bisphenols, and metabolites of polyaromatic hydrocarbons (PAHs). The children's group consists of 50.4% boys and 49.5% girls, of which 44.1% live in cities, 29.0% live in towns/suburbs, and 26.8% live in rural areas. The teenagers' group includes 50.6% girls and 49.4% boys, with 37.7% of residents in cities, 31.2% in towns/suburbs, and 30.2% in rural areas. The adult group consists of 52.6% women and 47.4% men, 71.9% live in cities, 14.2% in towns/suburbs, and only 13.4% live in rural areas. The study population approaches the characteristics of the general European population based on age-matched EUROSTAT EU-28, 2017 data; however, individuals who obtained no to lower educational level (ISCED 0-2) are underrepresented. The data on internal human exposure to priority chemicals from this unique cohort will provide a baseline for Europe's strategy towards a non-toxic environment and challenges and recommendations to improve the sampling frame for future EU-wide HBM surveys are discussed.

Prenatal stress and its association with amygdala-related structural covariance patterns in youth

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Prenatal exposure to stress predicts amygdala degree centrality in young adulthood.

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High (vs. low) stress group showed lower structural covariance degree of amygdala.

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These effects were particularly significant in men.

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Global network parameters did not drive these effects.

Background

Prenatal stress influences brain development and mood disorder vulnerability. Brain structural covariance network (SCN) properties based on inter-regional volumetric correlations may reflect developmentally-mediated shared plasticity among regions. Childhood trauma is associated with amygdala-centric SCN reorganization patterns, however, the impact of prenatal stress on SCN properties remains unknown.

Methods

The study included participants from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) with archival prenatal stress data and structural MRI acquired in young adulthood (age 23–24). SCNs were constructed based on Freesurfer-extracted volumes of 7 subcortical and 34 cortical regions. We compared amygdala degree centrality, a measure of hubness, between those exposed to high vs. low (median split) prenatal stress, defined by maternal reports of stressful life events during the first (n = 93, 57% female) and second (n = 125, 54% female) half of pregnancy. Group differences were tested across network density thresholds (5–40%) using 10,000 permutations, with sex and intracranial volume as covariates, followed by sex-specific analyses. Finally, we sought to replicate our results in an independent all-male sample (n = 450, age 18–20) from the Avon Longitudinal Study of Parents and Children (ALSPAC).

Results

The high-stress during the first half of pregnancy ELSPAC group showed lower amygdala degree particularly in men, who demonstrated this difference at 10 consecutive thresholds, with no significant differences in global network properties. At the lowest significant density threshold, amygdala volume was positively correlated with hippocampus, putamen, rostral anterior and posterior cingulate, transverse temporal, and pericalcarine cortex in the low-stress (p(FDR) < 0.027), but not the high-stress (p(FDR) > 0.882) group. Although amygdala degree was nominally lower across thresholds in the high-stress ALSPAC group, these results were not significant.

Conclusion

Unlike childhood trauma, prenatal stress may shift SCN towards a less amygdala-centric SCN pattern, particularly in men. These findings did not replicate in an all-male ALSPAC sample, possibly due to the sample’s younger age and lower prenatal stress exposure.

Tracking of anthropometric characteristics from childhood to adolescence: an 8-year follow-up findings from the Czech ELSPAC study

BACKGROUND

Although evidence suggests that obesity track well from childhood to adolescence, most of the research has been done in Western and high-income countries. Moreover, most of the studies have tracked body-mass index, as a proxy of nutritional status, while tracking characteristics of circumferences and skinfold thicknesses have been less studies. Therefore, the main purpose of the study was to explore tracking characteristics of complete anthropometric data from childhood to adolescence.

METHODS

This sub-study was part of the Czech ELSPAC study. In the present 8-year longitudinal study, we collected information from pediatrician's medical records at the ages of 8 y (n = 888), 11 y (n = 1065), 13 y (n = 811) and 15 y (n = 974), including circumferences (head, chest, waist, hips, and arm), indices (body-mass index, waist-to-hip ratio and waist-to-height ratio) and skinfold thicknesses (biceps, triceps, subscapula, suprailiaca, thigh and the sum of 5 skinfolds). Participants were recruited from the two selected regions of the Czech Republic (Brno and Znojmo). Linear generalized estimating equations were conducted to analyze tracking patterns over an 8-year follow-up period for all anthropometric measurements.

RESULTS

Tracking coefficients were moderate to strong, ranging from 0.40 to 0.62 for circumferences, 0.41 to 0.74 for indices and 0.72 to 0.86 for skinfolds. According to body-mass index and waist circumference standards, overweight/obese children and children with abdominal obesity at the age of 8 y were 11.31 (95% CI = 8.41 to 15.22, p < 0.001) and 10.73 (95% CI = 7.93 to 14.52, p < 0.001) more likely to remain overweight/obese and to have abdominal obesity at the age of 15 y.

CONCLUSIONS

Findings show moderate to strong tracking of anthropometric characteristics, i.e. circumferences track moderately well, while strong tracking for indices and skinfold thicknesses is observed. Moreover, strong tracking of general overweight/obesity and abdominal obesity between ages 8 y and 15 y indicates that the detection of these risk factors at the beginning of primary school should be advocated.

Maternal Pre-Pregnancy Nutritional Status and Physical Activity Levels and a Sports Injury Reported in Children: A Seven-Year Follow-Up Study

Objective: Our aim was to analyze dose–response associations between maternal pre-pregnancy body mass index and physical activity levels with childhood sports injury rates. Methods: Participants included pre-pregnant mothers (n = 4811) and their children at the age of 7 years (n = 3311). Maternal anthropometry (height, weight, and body mass index), time spent in physical activity, and education level were recorded. All sports injuries were defined as injuries reported in the past year by the children at the age of 7 years. Results: Children whose mothers were overweight/obese in the pre-pregnancy period were 2.04 (OR = 2.04, 95% CI = 1.12–3.71) times more likely to report a sports injury at the age of 7 years. Underweight mothers exhibited a 74% decrease in the odds of their children reporting a sports injury at follow-up (OR = 0.26, 95% CI = 0.10–0.68). Finally, an increase in maternal physical activity across the last three quartiles was associated with a lower odds of sports injuries. Conclusions: The risk of reporting a sports injury was greater for children whose mothers were overweight/obese in the pre-pregnancy period. However, there was a lower risk with both maternal underweight status and increasing minutes of physical activity.

Association of Picky Eating with Weight and Height—The European Longitudinal Study of Pregnancy and Childhood (ELSPAC–CZ)

Objective: This study aimed to evaluate whether preschool children identified as picky eaters showed differences in anthropometric characteristics (weight and height) from their non-picky peers at 15 years of age. Design: This study was performed among the cohort members of the EL- SPAC–CZ study, a longitudinal study of pregnancy and childhood. The analysis included 2068 children (997 girls and 1071 boys) followed between births and 15 years of age. Picky eaters were identified at 1.5, 3, and 5 years of age. Anthropometric characteristics were measured at 15 years of age (15 years). Results: Picky eaters (n = 346; 16.7%) had a lower weight and height than non-picky eaters (n = 1722; 83.3%) at 15 years. This difference in weight and height was maintained after controlling for sex of the child, birth weight, birth length, maternal education, family structure at 15 years, and maternal age at childbirth. The picky children were on average 2.3 kg lighter and 0.8 cm shorter than non- picky children at 15 years. Conclusions: Persistent picky eating in preschool children is related to lower weight and height at 15 years of age in ELSPAC–CZ study.

Tracking of Maternal Physical Activity and Sport Participation over 11 Years: Findings from the Czech ELSPAC Study

Purpose: Tracking of physical activity (PA) and sport participation (SP) during motherhood is poorly understood. The purpose of the study was to analyze the extent of tracking of maternal PA and SP. Methods: In this investigation, data were collected from the Czech ELSPAC study subsample of 4811 and 2609 women measured postnatally (1991-1992) and after 11 years of follow-up (2002-2003), respectively. The structured questionnaire was used to assess the participation and average weekly time spent in PA, and the frequency of engaging in different sports (running, cycling, strength training, racket sports, swimming, and team sports). Tracking was calculated using generalized estimating equations (GEE) with beta coefficients (β), odds ratios (ORs), and 95% confidence intervals (95% CI). Results: Moderately high tracking coefficients were observed for cycling (β = 0.69, 95% 0.67-0.72), strength training (β = 0.59, 95% 0.56-0.63), and weekly time spent in PA (β = 0.53, 95% 0.38-0.66); meanwhile, moderate tracking coefficients were generated for swimming (β = 0.48, 95% 0.44-0.52), team sports (β = 0.44, 95% 0.39-0.48), racket sports (β = 0.44, 95% 0.39-0.48), and running (β = 0.35, 95% 0.30-0.40). Mothers who did not participate in PA at baseline were 81% more likely not to participate in it at follow-up (OR = 1.81, 95% CI 1.53-2.13). Conclusion: Cycling- and strength-related activities and weekly PA were tracked moderately-to-moderately high during motherhood. Moreover, the strong tracking of physical inactivity indicates that the detection of this risk factor before pregnancy should be advocated.

Dietary patterns and birth outcomes in the ELSPAC pregnancy cohort

OBJECTIVES

The aim of this study was to identify dietary patterns in a Czech pregnancy cohort established in the early postcommunist era and investigate associations between dietary patterns, maternal characteristics and birth outcomes.

METHODS

Pregnant women were recruited for the Czech part of the European Longitudinal Study of Pregnancy and Childhood. A self-reported questionnaire answered in late pregnancy was used to assess information about the weekly intake of 43 food items. Information about birth outcomes (birth weight, height, ponderal index, head circumference, cephalisation index, gestational length and Apgar score) was obtained from the National Registry of Newborns. Complete details on diet and birth outcomes were available for 4320 mother-infant pairs.

RESULTS AND CONCLUSION

The food items were aggregated into 28 variables and used for extraction of two dietary patterns by principal component factor analysis. The patterns were denoted 'unhealthy' and 'healthy/traditional' based on the food items with the highest factor loadings on each pattern. The 'unhealthy' pattern had high positive loadings on meat, processed food and confectionaries. In contrast, the 'healthy/traditional' pattern had high positive loadings on vegetables, dairy, fruits and wholemeal bread. Following adjustment for covariates, we found that high adherence to the unhealthy pattern (expressed as beta for 1 unit increase in pattern score), that is, the higher consumption of less healthy foods, was associated with lower birth weight: -23.8 g (95% CI -44.4 to -3.2) and length: -0.10 cm (95% CI -0.19 to -0.01) and increased cephalisation index: 0.91 μm/g (95% CI 0.23 to 1.60). The 'healthy/traditional' pattern was not associated with any birth outcomes. This study supports the recommendation to eat a healthy and balanced diet during pregnancy.

Prenatal psychosocial stress and children's sleep problems: Evidence from the ELSPAC-CZ study

Prenatal exposure to maternal stress may increase the risk of developing sleep problems in childhood. This study examined the association between prenatal stressful life events (PSLE) and children's sleep problems, taking into consideration their trajectory over time. Data were obtained from the Czech portion of the European Longitudinal Cohort Study of Pregnancy and Childhood (ELSPAC-CZ; N = 4,371 children). Mothers reported PSLE using an inventory of 42 life events and child sleep problems at five time-points (child age of 1.5, 3, 5, 7, and 11 years). The association was tested by a Poisson latent growth model, controlling for maternal and family demographics, birth characteristics, maternal depression, and alcohol use in pregnancy. The average rate of sleep problems was 2.06 (p < 0.001) at the age of 1.5 years and the rate of sleep problems decreased in a linear fashion over time (estimate = -0.118; p < 0.001). A higher number of PSLE was associated with a higher rate of sleep problems at the age of 1.5 years (incidence rate ratio [IRR] per interquartile range = 1.08, 95% confidence interval [CI] 1.05-1.12, p < 0.001) and with a reduced rate of decrease in sleep problems between the ages of 1.5 and 11 years (p < 0.001). Thus, PSLE were associated with chronicity of sleep problems in addition to their amount during early childhood. Prenatal exposure to stress may predispose individuals to the development of sleep problems in later life.

Omouma: a prospective mother and child cohort aiming to identify early biomarkers of pregnancy complications in women living in Qatar

BACKGROUND

Pregnancy is governed by multiple molecular and cellular processes, which might influence pregnancy health and outcomes. Failure to predict and understand the cause of pregnancy complications, adverse pregnancy outcomes, infant's morbidity and mortality, have limited effective interventions. Integrative multi-omics technologies provide an unbiased platform to explore the complex molecular interactions with an unprecedented depth. The objective of the present protocol is to build a longitudinal mother-baby cohort and use multi-omics technologies to help identify predictive biomarkers of adverse pregnancy outcomes, early life determinants and their effect on child health.

METHODS/DESIGN

One thousand pregnant women with a viable pregnancy in the first trimester (6-14 weeks of gestation) will be recruited from Sidra Medicine hospital. All the study participants will be monitored every trimester, at delivery, and one-year post-partum. Serial high-frequency sampling, including blood, stool, urine, saliva, skin, and vaginal swabs (mother only) from the pregnant women and their babies, will be collected. Maternal and neonatal health, including mental health and perinatal growth, will be recorded using a combination of questionnaires, interviews, and medical records. Downstream sample processing including microbial profiling, vaginal immune response, blood transcriptomics, epigenomics, and metabolomics will be performed.

DISCUSSION

It is expected that the present study will provide valuable insights into predicting pregnancy complications and neonatal health outcomes. Those include whether specific microbial and/or epigenomics signatures, immune profiles are associated with a healthy pregnancy and/or complicated pregnancy and poor neonatal health outcome. Moreover, this non-interventional cohort will also serve as a baseline dataset to understand how familial, socioeconomic, environmental and lifestyle factors interact with genetic determinants to influence health outcomes later in life. These findings will hold promise for the diagnosis and precision-medicine interventions.

HBM4EU combines and harmonises human biomonitoring data across the EU, building on existing capacity - The HBM4EU survey

As part of the Human Biomonitoring for Europe (HBM4EU) initiative a human biomonitoring (HBM) survey is conducted in 21 countries. This survey builds on existing HBM capacity in Europe by aligning national or regional HBM studies. The survey targets 3 age groups (i) children aged 6-11 years, (ii) teenagers aged 12-19 years and (iii) young adults aged 20-39 years and includes a total of 9493 participants (3151 children, 2953 teenagers and 3389 young adults). Depending on the age group, internal exposure to phthalates and substitute Hexamoll® DINCH, brominated and organophosphorus flame retardants, per-/poly-fluorinated compounds, cadmium, bisphenols and/or polycyclic aromatic hydrocarbons are assessed. The main goal of the programme is to obtain quality controlled and comparable HBM data of exposure to chemicals, prioritized under HBM4EU, with European wide coverage to inform the development of environment and health policies. This paper describes the framework of the HBM4EU survey and the approach that has been applied to align European HBM initiatives across Europe.

Birth weight rather than birth length is associated with childhood behavioural problems in a Czech ELSPAC cohort

Many physical and psychological characteristics are influenced by prenatal development. Some studies have located links between low birth parameters and behavioural problems, with the latter in turn associated with educational progress, career success, overall health, and subsequent life events. However, few studies have investigated whether this association also applies to children in the normal birth growth range. This study thus investigates the relationship between normal-range birth length, weight, and behavioural problems at the age of seven. We use data from the Czech part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) cohort, which provides comprehensive insight into a post-communist country undergoing a period of economic transition. Childhood behavioural problems were measured in 1,796 children using the Strengths and Difficulties Questionnaire. Associations were modelled using weighted logistic regression. Birth weight was found to be linked to the total difficulties score, hyperactivity, and peer relationship problems subscales in a fully adjusted model while birth length was not significantly associated with any subscale in the fully adjusted model. We thus conclude that normal-range birth weight is associated with behavioural problems. It can therefore be assumed that the odds of behavioural problems and their consequences can be mitigated by preventive programs targeting pregnant women and children with lower but still normal weight.

Assessing Stress in Pregnancy and Postpartum: Comparing Measures

Introduction

Measuring early-life psychosocial stress is complicated by methodological challenges. This paper compares three survey instruments for the assessment of life in pregnancy/postpartum and investigates the effects of the timing of early-life stress for emotional/behavioral difficulties (EBD) of offspring during mid/late childhood and adolescence.

Methods

Observational data were obtained from the European Longitudinal Cohort Study of Pregnancy and Childhood (ELSPAC-CZ), which included 4811 pregnancies in two Czech metropolitan areas. We used data collected between 1991 and 2010 at 20 weeks of pregnancy (T1), after delivery (T2), at 6 months postpartum (T3), and at child’s age of 7 years (T4), 11 years (T5), 15 years (T6), and 18 years (T7). Life stress was assessed with (1) the Edinburgh Postnatal Depression Scale (EPDS), (2) a stressful life events (SLE) count based on 42-item inventory, and (3) the SLE measure weighted by perceived stressfulness (PS). Each stress measure was administered at T1, T2, and T3. Child’s EBD were assessed with the Strengths and Difficulties Questionnaire at T4, T5, T6, and T7.

Results

Each stress measure independently predicted long-term EBD. The best data fit was obtained in a model combining EPDS and SLE. Effect sizes for SLEs decreased between the first half of pregnancy and postpartum, while the effect of EPDS increased.

Discussion

SLE-based methods capture an aspect of perinatal stress not adequately assessed by EPDS. Combination of psychological distress measures and SLE-based measures is optimal in predicting EBD of the child. Stress measures based on SLE are suitable for early pregnancy, while self-reports of depressive symptoms may perform better in postpartum.

Epigenetic clock as a correlate of anxiety

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In young adult women, slower epigenetic clock predicted less symptoms of anxiety.

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In young adult women, slower epigenetic clock predicted greater cortical GM volume.

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This effect of epigenetic clock in young adult women was largest in frontal lobe.

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The link of epigenetic clock and anxiety was mediated by GM volume in frontal lobe.

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No similar relationships were found in young adult men or adolescents.

DNA methylation changes consistently throughout life and age-dependent alterations in DNA methylation can be used to estimate one’s epigenetic age. Post-mortem studies revealed higher epigenetic age in brains of patients with major depressive disorder, as compared with controls. Since MDD is highly correlated with anxiety, we hypothesized that symptoms of anxiety, as well as lower volume of grey matter (GM) in depression-related cortical regions, will be associated with faster epigenetic clock in a community-based sample of young adults. Participants included 88 young adults (53% men; 23–24 years of age) from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) who participated in its neuroimaging follow-up and provided saliva samples for epigenetic analysis. Epigenetic age was calculated according to Horvath (Horvath, 2013). Women had slower epigenetic clock than men (Cohen’s d = 0.48). In women (but not men), slower epigenetic clock was associated with less symptoms of anxiety. In the brain, women (but not men) with slower epigenetic clock had greater GM volume in the cerebral cortex (brain size-corrected; R² = 0.07). Lobe-specific analyses showed that in women (but not men), slower epigenetic clock was associated with greater GM volume in frontal lobe (R² = 0.16), and that GM volume in frontal lobe mediated the relationship between the speed of epigenetic clock and anxiety trait (ab = 0.15, SE = 0.15, 95% CI [0.007; 0.369]). These findings were not replicated, however, in a community-based sample of adolescents (n = 129; 49% men; 12–19 years of age), possibly due to the different method of tissue collection (blood vs. saliva) or additional sources of variability in the cohort of adolescents (puberty stages, socioeconomic status, prenatal exposure to maternal smoking during pregnancy).

Temporally and sex-specific effects of maternal perinatal stress on offspring cortical gyrification and mood in young adulthood

Maternal stress during pregnancy and shortly thereafter is associated with altered offspring brain development that may increase risk of mood and anxiety disorders. Cortical gyrification is established during the prenatal period and the first 2 years of life and is altered in psychiatric disorders. Here, we sought to characterize the effects of perinatal stress exposure on offspring gyrification patterns and mood dysregulation in young adulthood. Participants included 85 young adults (56.5% women; 23–24 years) from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) with perinatal stress data across four distinct timepoints and structural MRI data from young adulthood. Perinatal stress exposure was measured as maternal stress during first and second half of pregnancy, first 6 months, and 6–18 months after birth. Cortical gyrification and mood dysregulation were quantified using local gyrification index (LGI), computed with Freesurfer, and the Profile of Mood States questionnaire, respectively. Perinatal stress predicted cortical gyrification in young adulthood, and its timing influenced location, direction, and sex‐specificity of effects. In particular, whereas early prenatal stress was associated with sex‐dependent medium‐to‐large effects in large temporal, parietal, and occipital regions (f² = 0.19–0.38, p < .001), later perinatal stress was associated with sex‐independent small‐to‐medium effects in smaller, more anterior regions (f² = 0.10–0.19, p < .003). Moreover, in females, early prenatal stress predicted higher LGI in a large temporal region, which was further associated with mood disturbance in adulthood (r = 0.399, p = .006). These findings point out the long‐term implications of perinatal stress exposure for cortical morphology and mood dysregulation.

Socioeconomic characteristics, family structure and trajectories of children's psychosocial problems in a period of social transition

Data from the Czech part of the European Longitudinal Study of Pregnancy and Childhood offer a unique opportunity to examine a period of changing socioeconomic structure of the country. Our aim was to analyse the association between socioeconomic status, family structure and children's psychosocial problems at the age of 7, 11, 15 and 18 years in 3,261 subjects and compare our results with findings from western settings. The Strengths and Difficulties Questionnaire (SDQ) and its five subscales were used to assess individual problem areas (emotional symptoms, peer problems, hyperactivity, conduct problems) and prosocial behaviour. Socioeconomic status was represented by maternal education and three forms of family structure were identified: nuclear family, new partner family and single parent family. The SDQ subscale score over time was modelled as a quadratic growth curve using a linear mixed-effects model. Maternal university education was associated with a faster decline in problems over time for all five SDQ subscales. Problems in children from nuclear families were found to be significantly lower than in children from single parent families for all SDQ subscales with the exception of peer problems. Compared to nuclear families, children from new partner families scored significantly higher in hyperactivity and conduct problems subscales. The nuclear family structure and higher maternal education have been identified as protective factors for children's psychosocial problems, in agreement with findings from western settings. Adopting a longitudinal perspective was shown as essential for providing a more complex view of children's psychosocial problems over time.

Matrix metalloproteinases gene variants and dental caries in Czech children

Background

Matrix metalloproteinases (MMPs) play an important role in tooth formation and the mineralization of dental tissue. The aim of the study was to analyse Czech children with primary/permanent dentition polymorphisms in those genes encoding MMP2, MMP3, MMP9, MMP13, MMP16, and MMP20, which had been previously associated with dental caries in other populations.

Methods

In total, 782 Czech children were included in this case-control study. DNA samples were taken from 474 subjects with dental caries (with decayed/missing/filled teeth, DMFT ≥ 1) and 155 caries free children (DMFT = 0) aged 13–15 years, as well as 101 preschool children with early childhood caries (ECC, dmft ≥ 1) and 52 caries free children (dmft = 0), were analyzed for nine MMPs single nucleotide polymorphisms (SNPs) using real time polymerase chain reaction TaqMan assays.

Results

There were no significant differences in the allele and/or genotype frequencies of all the studied MMPs SNPs among children with dental caries in primary/permanent dentition and the healthy controls (P > 0.05). In addition, similar allele or genotype frequencies of the studied MMPs SNPs were found in children with severe dental caries in their permanent teeth (children with DMFT ≥ 6) and the healthy controls (DMFT = 0, P > 0.05).

Conclusions

This study demonstrated the lack of association between the selected SNPs in candidate genes of MMPs and the susceptibility to or severity of dental caries in both primary and permanent dentitions in Czech children.

Prenatal Stress, Mood, and Gray Matter Volume in Young Adulthood

This study aimed to determine whether prenatal stress, measured by the number of stressful life events during the first 20 weeks of pregnancy, might relate to mood dysregulation and altered brain structure in young adulthood. Participants included 93 young adults from a community-based birth cohort from the Czech Republic. Information on prenatal stress exposure was collected from their mothers in 1990-1992. Magnetic resonance imaging (MRI) and mood-related data were collected from the young adults in 2015. MRI analyses focused on overall gray matter (GM) volume and GM volume of cortical regions previously associated with major depression. Higher prenatal stress predicted more mood dysregulation, lower overall GM volume, and lower GM volume in mid-dorsolateral frontal cortex, anterior cingulate cortex, and precuneus in young adulthood. We observed no prenatal stress by sex interactions for any of the relations. We conclude that prenatal stress is an important risk factor that relates to worse mood states and altered brain structure in young adulthood irrespective of sex. Our results point to the importance and long-lasting effects of prenatal programming and suggest that offspring of mothers who went through substantial stress during pregnancy might benefit from early intervention that would reduce the odds of mental illness in later life.

Association between Stress Urinary Incontinence and Depressive Symptoms after Birth: the Czech ELSPAC Study

The study objectives were to (1) identify risk factors related to stress urinary incontinence (SUI) and postnatal depression (PD) after birth, and (2) investigate both possible directions of association between SUI and PD in population-based sample of Czech mothers. 3,701 nulliparous and multiparous women completed the self-reported questionnaires at 6 weeks and 6 months after birth and were included into the analyses of this prospective cohort study. Unadjusted and adjusted logistic regressions examined relationship between SUI a PD accounting for range of other risk factors. During the first 6 months after birth, 650 mothers (17.6%) developed SUI and 641 (17.3%) displayed signs of PD. The mode of delivery, parity and higher BMI were associated with SUI. The rate of PD symptoms was higher in mothers with positive history of prenatal depression, and in divorced or widowed mothers. Both conditions were associated with worse self-reported health, back pain and stop-smoker status. Initially, SUI at 6 weeks was slightly, but significantly associated with onset of PD at 6 months (OR 1.51, 95% CI 1.02–2.23) while PD at 6 weeks was not significantly related to new cases of SUI at 6 months (OR 1.48, 95% CI 0.91–2.39). After full adjustment these OR reduced to 1.41 and 1.38 (both non-significant), respectively. SUI and PD are common conditions in women postpartum that share some risk factors. Our study suggests that both directions of their relationship are possible although a larger study is needed to confirm our findings.

Childhood Sleep Functioning as a Developmental Precursor of Adolescent Adjustment Problems

Sleep has been linked to adjustment difficulties in both children and adolescents; yet little is known about the long-term impact of childhood sleep on subsequent development. This study tested whether childhood sleep problems, sleep quantity, and chronotype predicted internalizing and externalizing problems during adolescence. Latent Growth Modeling using the Czech portion of the European Longitudinal Study of Pregnancy and Childhood (N = 4393) was utilized to test the developmental trajectories of sleep characteristics (from 1.5 to 7 years) as predictors of adjustment problems trajectories (from 11 to 18 years). Findings provided evidence that children with higher levels of sleep problems at 1.5 years (and throughout childhood) reported higher levels of internalizing and externalizing problems at age 11. Additionally, greater eveningness at age 1.5 predicted a greater increase in externalizing problems from ages 11 to 18 years. The results emphasize the importance of childhood sleep problems in evaluating the risk of future adjustment difficulties.

Gender discrimination and depressive symptoms among child-bearing women: ELSPAC-CZ cohort study

BACKGROUND

Depression is approximately two-fold more prevalent among women than men. Social theories suggest that discrimination is a pathway through which gender inequalities affect women's lives, but data are lacking. This cohort study evaluates whether perceived gender discrimination is linked to depressive symptoms among child-bearing women.

METHODS

Data were obtained from 4,688 participants enrolled in pregnancy in 1991-92 in the European Longitudinal Cohort Study of Pregnancy and Childhood, Czech Republic. Perceived gender discrimination was assessed in mid-pregnancy, year seven, and year eleven. Depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale at eight time-points between mid-pregnancy and year eleven post-delivery. Linear mixed error-component models of depressive symptoms were estimated.

FINDINGS

Perceived gender discrimination, reported by 10.7% of women, was related to higher depressive symptoms, both in the unadjusted analysis (b = 0.15 [95% confidence interval (CI): 0.12, 0.19], p < 0.001) and in the fully adjusted model (b = 0.12 [95% CI: 0.09, 0.16], p < 0.001). Covariates linked to higher depressive symptoms included financial hardship (b = 0.12 [95% CI: 0.10, 0.14], p < 0.001), childhood emotional/physical neglect (b = 0.18 [95% CI: 0.14, 0.22], p < 0.001), and childhood sexual abuse (b = 0.04 [95% CI: 0.03, 0.06], p < 0.001); an inverse relationship was evident for social support (-0.05 [95% CI: -0.07, -0.04], p < 0.001) and having a partner who performs female-stereotypical household tasks (b=-0.03 [95% CI: -0.05, -0.01], p = 0.001).

INTERPRETATION

The findings provide the first evidence that perceived gender discrimination is associated with depressive symptoms among child-bearing women. Social intervention programs aimed at reducing gender discrimination can potentially contribute to better mental health of women.

FUNDING

Bill and Melinda Gates Foundation.

Sibling relatedness rather than father absence predicts earlier age at menarche in ELSPAC cohort

Many studies during the past 50 years have found an association between father absence and earlier menarche. In connection with these findings, several evolutionary theories assume that father absence is a causal factor accelerating reproductive development. However, a recent study analysing data from the Avon Longitudinal Study of Parents and Children (ALSPAC) found that father absence does not predict age at menarche when adjusted for sibling relatedness. In this study, we have replicated these results in the Czech section of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC), which used the same questionnaires as ALSPAC to study a geographically distinct population. Our results support the conclusion that sibling relatedness rather than father absence predicts age at menarche. Furthermore, our results show that age at menarche in 1990s UK and Czech cohorts is very similar despite socioeconomic differences between the two countries.

Early-life exposure to household chemicals and wheezing in children

The prevalence of the asthmatic symptoms among children increases globally over the time. Reduced exposure to pathogens in early childhood and increased exposure to anthropogenic irritants result in increased risk of wheezing in children, and all of this may be related to the usage of household chemicals. Objective of this analysis thus was to study the potential effects of overall exposure to home chemicals in the early life on the phenotypes of wheezing from birth until five years of age. 3411 mother-infant pairs from the Czech part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC-CZ) participated in the study. The exposure was estimated by the composite household chemical score from 18 chemical-based products. Social, medical and environmental factors were taken into account as covariates in multivariable multinomial logistic regression using phenotypes of wheezing as a study outcome. We were able to determine the association between several wheezing childhood phenotypes and the frequent usage of household chemicals in the fully adjusted model. Statistically significant odds ratios (OR) for increasing exposures per 1 SD of exposure score were obtained for the intermediate onset transient (OR 1.27, 95% CI 1.10-1.47), intermediated onset persistent (OR 1.23, 95% CI 1.03-1.46), and early onset persistent phenotypes (OR 1.36, 95% CI 1.04-1.77) in comparison to never wheezing children. Moreover, the persistent phenotypes were significantly associated with school age asthma. Our study has shown the negative role of the increased household chemicals usage on the respiratory outcomes in children up to five years of age. Overall evaluation of the household chemical exposure may be useful tool for any large epidemiological studies.

Sleep Quantity and Problems as Mediators of the Eveningness-Adjustment Link during Childhood and Adolescence

Chronotype, or morningness/eveningness, has been associated with adjustment in both children and adolescents. Specifically, eveningness has been linked to adjustment difficulties; however, the mechanism underlying this association is poorly understood. The purpose of this study was to test whether the associations between eveningness and adjustment difficulties could be explained by an unfavorable impact of eveningness on sleep. Links from chronotype to internalizing problems and problem behaviors via sleep quantity and sleep problems were tested in a sample from the European Longitudinal Study of Pregnancy and Childhood (N = 3485; 48.8% female), both when the participants were children (7 years at T1, 11 at T2) and when they were adolescents (15 years at T1, 18 at T2). The findings provided evidence that eveningness predicted greater sleep problems and lower sleep quantity; however, only sleep problems predicted internalizing problems and problem behaviors. Sleep quantity did not mediate the eveningness-adjustment link, and sleep problems did so only in children. The findings show that sleep problems appear to be more important in explaining the eveningness-adjustment link rather than altered sleep quantity, commonly associated with eveningness.

Developmental origins of depression-related white matter properties: Findings from a prenatal birth cohort

Depression is the leading cause of years lost due to disability worldwide. Still, the mechanisms underlying its development are not well understood. This study aimed to evaluate white-matter properties associated with depressive symptomatology in young adulthood and their developmental origins. Diffusion tensor imaging and assessment of depressive symptomatology were conducted in 128 young adults (47% male, age 23-24) from a prenatal birth cohort (European Longitudinal Study of Pregnancy and Childhood). For a subset of these individuals, the database included information on prenatal stress (n = 93) and depressive symptoms during adolescence (assessed repeatedly at age 15 and 19). Depressive symptoms in young adulthood were associated with lower fractional anisotropy in the left and right cingulum and higher fractional anisotropy in the right corticospinal tract and superior longitudinal fasciculus. Further analyses revealed that prenatal stress and depressive symptomatology during adolescence were independent predictors of altered white-matter properties in the cingulum in young adulthood. We conclude that typically developing young adults with more depressive symptoms already exhibit tract-specific alterations in white-matter properties and that prenatal stress and depressive symptomatology during adolescence might contribute to their development.

Perinatal Maternal Stress and Susceptibility to Infectious Diseases in Later Childhood: An Early Life Programming Perspective

There is evidence of transmission of stress-related dysregulation from parents to offspring during early developmental stages, leading to adverse health outcomes. This study investigates whether perinatal stress is linked to the risk of infectious diseases in children aged 7-11 years. We hypothesize that stress exposure during pregnancy and the first 6 months after birth independently predict common infectious diseases. Data are obtained from ELSPAC-CZ, a prospective birth cohort. Maternal stress, operationalized as the number of life events, is examined for pregnancy and the first 6 months postpartum. Children's diseases include eye infection, ear infection, bronchitis/lung infection, laryngitis, strep throat, cold sores, and flu/flu-like infection. More prenatal and postnatal life events are both independently linked to a higher number of infectious diseases between the ages of 7-11 years. The effect is larger for postnatal vs. prenatal events, and the effect of prenatal events is attenuated after maternal health in pregnancy is controlled. The results suggest that perinatal stress is linked to susceptibility to infectious diseases in school-age children. Interventions to address stress in pregnant and postpartum women may benefit long-term children's health.

Perinatal stress and human hippocampal volume: Findings from typically developing young adults

The main objective of this study was to investigate the impact of prenatal and early postnatal stress on hippocampal volume in young adulthood. In sharp contrast to numerous results in animal models, our data from a neuroimaging follow-up (n = 131) of a community-based birth cohort from the Czech Republic (European Longitudinal Study of Pregnancy and Childhood) showed that in typically developing young adults, hippocampal volume was not associated with birth weight, stressful life events during the prenatal or early postnatal period, or dysregulated mood and wellbeing in the mother during the early postnatal period. Interestingly, mother’s anxiety/co-dependence during the first weeks after birth did show long-lasting effects on the hippocampal volume in young adult offspring irrespective of sex. Further analyses revealed that these effects were subfield-specific; present in CA1, CA2/3, CA4, GC-DG, subiculum, molecular layer, and HATA, hippocampal subfields identified by translational research as most stress- and glucocorticoid-sensitive, but not in the remaining subfields. Our findings provide evidence that the type of early stress is critical when studying its effects on the human brain.

Is Perceived Discrimination in Pregnancy Prospectively Linked to Postpartum Depression? Exploring the Role of Education

Objectives The role of perceived discrimination in postpartum depression is largely unknown. We investigate whether perceived discrimination reported in pregnancy contributes to postpartum depression, and whether its impact varies by education level. Methods Prospective data are a part of European Longitudinal Study of Pregnancy and Childhood, the Czech Republic. Surveys were collected in mid-pregnancy and at 6 months after delivery. Depression was measured using Edinburgh Postnatal Depression Scale. Generalized linear models were estimated to test the effects of perceived discrimination on postpartum depression. Results Multivariate models revealed that among women with low education, discrimination in pregnancy was prospectively associated with 2.43 times higher odds of postpartum depression (p < .01), after adjusting for antenatal depression, history of earlier depression, and socio-demographic background. In contrast, perceived discrimination was not linked to postpartum depression among women with high education. Conclusions Perceived discrimination is a risk factor for postpartum depression among women with low education. Screening for discrimination and socio-economic disadvantage during pregnancy could benefit women who are at risk for mental health problems.

Estimated dietary iodine intake as a predictor of placental size: evidence from the ELSPAC study

Background

The relationship between low iodine status and pregnancy-associated comorbidities has been known for decades. The relationship between iodine intake and placental pathologies is, however, far less clear. This study was designed to examine the relationship between dietary iodine intake and placental size while also focusing on typical adverse pregnancy outcomes.

Method

The dietary iodine intake of 4711 pregnant women enrolled in the Czech part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) in 1990–1991 was established using a 145-item food frequency questionnaire. Multivariate linear regression models were used to estimate the relationship between dietary iodine intake during pregnancy and placental weight. Additional models were constructed to investigate the relationship between estimated dietary iodine intake and adverse birth outcomes.

Results

The estimated average iodine intake in the ELSPAC cohort was 106.6 μg/day. In the fully adjusted model, estimated dietary iodine intake was found to be significantly negatively associated with placental weight (β = −0.025, 95% CI: -0.044; −0.006, p = 0.011). Moreover, estimated dietary iodine intake was found to be significantly positively associated with the birth weight / placental weight ratio in the fully adjusted model (β = −0.024, 95% CI: 0.004; 0.043, p = 0.016).

Conclusions

This study provides evidence of a relationship between estimated dietary iodine intake and placental weight and the birth weight / placental weight ratio. Additional research is warranted to provide more insight into the role of iodine in early as well as late placentation.

Role of combined prenatal and postnatal paracetamol exposure on asthma development: the Czech ELSPAC study

BACKGROUND

Prenatal and postnatal paracetamol exposure has been previously associated with asthma development in childhood in Western populations. We explore the association between prenatal and postnatal paracetamol exposure and asthma development in a Central European sample of Czech children, suggesting possible additive effect of the both exposures. Furthermore, since aspirin had been used more widely during study data collection in Central Europe, we also compared asthma development for those exposed to paracetamol and aspirin.

METHODS

We used data from 3329 children born in the 1990s as members of the prospective Czech European Longitudinal Study of Pregnancy and Childhood. Data about prenatal and postnatal paracetamol and aspirin exposure, and potential covariates were obtained from questionnaires completed by mothers. Data about incident asthma were obtained from paediatrician health records.

RESULTS

60.9% of children received paracetamol only postnatally, 1.5% only prenatally and 4.9% of children were exposed both during pregnancy and infancy. Prevalence of asthma in following population was 5% at 11 years. Being exposed to paracetamol both in prenatal and postnatal period was associated with asthma development (unadjusted OR 1.98, 95% CI 1.02 to 3.87). Being exposed only in the postnatal period was also significantly associated with increased risk of asthma. No association between prenatal exposure only and outcome was found. A higher but non-significant risk of asthma was observed for those whose mothers used paracetamol during pregnancy compared with those who used aspirin.

CONCLUSIONS

The main findings of this prospective birth cohort study add to previous observations linking prenatal and early postnatal paracetamol exposure to asthma development. However, the magnitude of effect is relatively modest, and therefore, we recommend paracetamol to remain the analgesic and antipyretic of choice throughout pregnancy and early childhood.

Lack of association between ENAM gene polymorphism and dental caries in primary and permanent teeth in Czech children

OBJECTIVES

The enamelin gene (ENAM) polymorphism (rs12640848) was recently associated with dental caries in primary teeth in Polish children. The aims of the present study were to prove this association in primary dentition and to find a possible effect of this variant on caries development in permanent dentition in Czech children.

MATERIALS AND METHODS

This study comprised 905 Czech children. Totally, 187 children aged 2-6 years with primary dentition [78 healthy subjects (with decayed/missing/filled teeth, dmft = 0) and 109 patients with early childhood caries (ECC; dmft ≥ 1)] were included in this case-control study. In addition, 177 subjects aged 13-15 years without caries (DMFT = 0) and 541 children with dental caries (DMFT ≥ 1) in permanent dentition were selected from the ELSPAC study. Genotype determination of the ENAM polymorphism (rs12640848) was based on the TaqMan method.

RESULTS

No significant differences in the allele or genotype frequencies between the caries-free children and those affected by dental caries were observed in both primary and permanent dentitions.

CONCLUSIONS

Lack of association between the ENAM polymorphism (rs12640848) and dental caries in Czech children was detected.

CLINICAL RELEVANCE

Although ENAM is considered as a candidate gene for dental caries, the presence of the ENAM variant (rs12640848) cannot be used as a risk factor of this multifactorial disease in the Czech population.

Lack of Association between BMP2/DLX3 Gene Polymorphisms and Dental Caries in Primary and Permanent Dentitions

The aim of this study was to analyze the association between BMP2 (rs1884302) and DLX3 (rs2278163) gene polymorphisms and dental caries in primary and permanent dentitions. A total of 914 subjects were genotyped by the TaqMan methods: 176 caries-free children (with Decayed/Missing/Filled Teeth, DMFT = 0), 542 patients with dental caries in permanent dentition (DMFT ≥1), 83 caries-free children with primary teeth (with decayed/missing/filled teeth, dmft = 0), and 113 children with early childhood caries (ECC, dmft ≥1). There were no significant differences in allele/genotype frequencies between patients with caries in permanent dentition/ECC and caries-free children or between patients with very low (DMFT = 0-2), low (DMFT = 3-5), moderate (DMFT = 6-8), or high (DMFT ≥9) caries experience. Variability in BMP2 and DLX3 was not associated with caries in the Czech population.

Sociodemographic and delivery risk factors for developing postpartum depression in a sample of 3233 mothers from the Czech ELSPAC study

BACKGROUND

In the postpartum period, certain groups of women are at a higher risk for developing depressive episodes. Several studies have described risk factors for developing postpartum depression (PPD). However, these studies have used limited numbers of participants, and therefore the estimated prevalence of PPD varies greatly.

METHODS

The objective of this study is to identify the main risk factors for developing PPD by using data collected via the Czech version of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC). This database provides a representative sample (n = 7589) observed prospectively and a large amount of data on depressive symptoms and on biological, socioeconomic, and environmental factors. The Edinburgh Postnatal Depression Scale (EPDS) was used to screen for incidence of PPD. The affective pathology was examined at three time points: before delivery, 6 weeks after delivery, and 6 months after delivery.

RESULTS

The prevalence of depressive symptoms before delivery was 12.8%, 6 weeks after delivery 11.8%, and 6 months after delivery 10.1%. The prevalence rates are based on women who completed questionnaires at all three time-points (N = 3233). At all three time points, the main risk factors for developing PPD identified as significant by both univariate and multivariate analysis were personal history of depressive episodes and mothers experiencing psychosocial stressors. Other risk factors occurring in both types of analysis were: family history of depression from expectant mother's paternal side (prenatal), mothers living without partners (6 weeks postpartum) and feelings of unhappiness about being pregnant (6 months postpartum). Several protective factors were also observed: male child gender (prenatal), primiparous mothers (6 months postpartum), and secondary education (prenatal, only by multivariate analysis). Significant risk factors found solely by univariate analysis were family history of depression in both parents of the expectant mother (prenatal and 6 weeks postpartum), family history of depression from subject's maternal side (6 months postpartum), unintentional pregnancy (prenatal and 6 weeks postpartum), feelings of unhappiness about being pregnant (prenatal and 6 weeks postpartum), primary education (prenatal and 6 weeks postpartum), mothers who opted not to breastfeed (6 months postpartum) and mothers living without partners (prenatal and 6 months postpartum). Family savings were identified as protective factor (prenatal and 6 months postpartum).

CONCLUSIONS

We identified significant predictors of PPD. These predictors can be easily detected in clinical practice, and systematic screening can lead to identifying potentially at risk mothers. Since the risk is linked with experience of psychosocial stressors it seems that they might benefit from increased psychosocial support to prevent affective pathology.

Vitamin D Receptor TaqI Gene Polymorphism and Dental Caries in Czech Children

AIM

We analyzed the VDR TaqI (rs731236) gene polymorphism in children with and those without dental caries.

METHODS

A total of 388 subjects, 153 caries-free (with decayed/missing/filled teeth [DMFT] = 0) and 235 children with dental caries (DMFT ≥1), were genotyped by the TaqMan method.

RESULTS

Although no significant differences in VDR TaqI allele and genotype frequencies between caries-free and caries-affected children were detected, a significant association between this polymorphism and gingivitis was found (p < 0.05).

CONCLUSIONS

In contrast to previous studies from China and Turkey, the VDR TaqI gene variant cannot be used as a marker for identification of Czech children with increased dental caries risk.