The Generation R Study: Biobank update 2015

Characterising developmental dynamics of adult epigenetic clock sites

BACKGROUND

DNA methylation (DNAm), an epigenetic mechanism that regulates gene activity in response to genetic and environmental influences, changes as we age. DNAm at specific sites on the genome can be used to calculate 'epigenetic clocks', which are powerful biomarkers of age, as well as of ageing. However, little is known about how these clock sites 'behave' during development and what factors influence their variability in early life. This knowledge could be used to optimise healthy ageing well before the onset of age-related conditions.

METHODS

We leveraged results from two longitudinal population-based cohorts (N = 5019 samples from 2348 individuals) to characterise trajectories of adult clock sites from birth to early adulthood. To explore what factors may drive early individual differences at these clock sites, we also tested for enrichment of genetic factors and prenatal exposures based on existing epigenome-wide association meta-analyses.

FINDINGS

We find that clock sites (i) diverge widely in their developmental trajectories, often showing non-linear change over time; (ii) are substantially more likely than non-clock sites to vary between individuals already from birth, differences that are predictive of DNAm variation at later ages; and (iii) show enrichment for genetic influences and prenatal environmental exposures, including prenatal smoking, diet and maternal physical health conditions.

INTERPRETATION

These results suggests that age(ing)-related epigenetic processes might originate-and differ between individuals-already very early in development. Understanding what drives these differences may in future help us to devise better strategies to promote healthy ageing.

FUNDING

This research was conducted while C.A.M.C. was a Hevolution/AFAR New Investigator Awardee in Aging Biology and Geroscience Research. Full personal funding details, as well as cohort funding details, can be found in the Acknowledgements.

Gestational organophosphate pesticide exposure and childhood cardiovascular outcomes

INTRODUCTION

The general population is chronically exposed to organophosphate pesticides through various routes including ingestion, hand-to-mouth contact, inhalation, and dermal contact. Exposure to organophosphate pesticides during pregnancy impairs fetal development, but the potential long-term effects of gestational organophosphate pesticide exposure are less well understood.

METHODS

We investigated associations between gestational organophosphate pesticide exposure and cardiovascular outcomes in 643 children in the Generation R Study, a prospective pregnancy cohort based in Rotterdam, The Netherlands. Urinary organophosphate pesticide metabolites (dimethyl [∑DMAP], diethyl [∑DEAP], and total dialkyl phosphate [∑DAP] metabolites) were quantified in three urine samples collected from pregnant participants, and their children were followed until age 10 years at which time cardiac magnetic resonance imaging, ultrasonography, blood pressure, and serum biomarkers assessed cardiovascular health. Linear regression models estimated associations (β and 95 % confidence interval [CI]) between a one-interquartile range (IQR) increase in averaged gestational exposure biomarker concentrations and z-scored pediatric cardiovascular outcomes. We investigated effect modification of associations by PON1 genotype.

RESULTS

Carotid intima-media thickness z-score was lower (β: -0.14 [95 % CI: -0.25, -0.02]) and HDL cholesterol z-score was higher (β: 0.14 [95 % CI: 0.02, 0.25]) for increases in ∑DEAP concentrations. Carotid intima-media distensibility z-score was lower (β: -0.08 [95 % CI: -0.19, 0.03]) for increases in ∑DMAP concentrations, and systolic blood pressure z-score was higher (β: 0.10 [95 % CI: -0.01, 0.21]) for increases in ∑DMAP and ∑DAP. Among those with PON1-161CC and PON1-L55MTT genotypes, higher organophosphate pesticide concentrations conferred an excess risk of adverse vascular and glycemic outcomes, respectively.

CONCLUSIONS

We observed heterogenous associations between gestational organophosphate pesticide exposure and pediatric cardiovascular health: an anti-atherogenic profile was observed for increases in ∑DEAP concentrations, and impairments in multiple aspects of cardiovascular health was observed for increases in ∑DMAP concentrations. PON1-161 and PON1-L55M single nucleotide polymorphisms modified associations for vascular and glycemic outcomes, respectively.

Family history of dementia and brain health in childhood and middle age: a prospective community-based study

We aimed to determine the association of family history of dementia with structural brain measures and cognitive performance in childhood and mid-life adulthood. We studied 1,259 parents (mean age: 47.3 years, range 31.9-67.4) and 866 of their children (mean age [range] at brain MRI: 9.9 years [8.8-11.9], and for cognition: 13.5 years [12.6-15.8]) of the population-based Generation R Study. Parents filled in a questionnaire on family history, and both parents and children underwent cognitive assessment and neuroimaging. Of all participants, 109 parents (8.6%) reported a parental family history of dementia and 73 children (8.4%) had a grandparental history of dementia with mean age of dementia diagnosis in those affected 75 years (± 7.3). We observed no associations of dementia family history with cognitive ability in either parents or their children, except for worse Purdue pegboard in parents with a parental history of dementia, compared to those without (mean difference [95%CI]: -1.23 [-2.15; -0.31], test range: 21-52). In parents and children, neuroimaging measures did not differ significantly by family history. Results did not depend on age, sex, and APOE genotype. Family history of dementia was associated with worse manual dexterity in mid-life adulthood, but not with any other measures of cognitive ability or subclinical brain health in childhood and mid-life. These findings suggest that the association of family history with dementia risk is due chiefly to neurodegenerative rather than neurodevelopmental processes, and might first present with reduced motor skills.

Prenatal exposure to common infections and newborn DNA methylation: A prospective, population-based study

BACKGROUND

Infections during pregnancy have been robustly associated with adverse mental and physical health outcomes in offspring, yet the underlying molecular pathways remain largely unknown. Here, we examined whether exposure to common infections in utero associates with DNA methylation (DNAm) patterns at birth and whether this in turn relates to offspring health outcomes in the general population.

METHODS

Using data from 2,367 children from the Dutch population-based Generation R Study, we first performed an epigenome-wide association study to identify differentially methylated sites and regions at birth associated with prenatal infection exposure. We also examined the influence of infection timing by using self-reported cumulative infection scores for each trimester. Second, we sought to develop an aggregate methylation profile score (MPS) based on cord blood DNAm as an epigenetic proxy of prenatal infection exposure and tested whether this MPS prospectively associates with offspring health outcomes, including psychiatric symptoms, BMI, and asthma at ages 13-16 years. Third, we investigated whether prenatal infection exposure associates with offspring epigenetic age acceleration - a marker of biological aging. Across all analysis steps, we tested whether our findings replicate in 864 participants from an independent population-based cohort (ALSPAC, UK).

RESULTS

We observed no differentially methylated sites or regions in cord blood in relation to prenatal infection exposure, after multiple testing correction. 33 DNAm sites showed suggestive associations (p < 5e10 - 5; of which one was also nominally associated in ALSPAC), indicating potential links to genes associated with immune, neurodevelopmental, and cardiovascular pathways. While the MPS of prenatal infections associated with maternal reports of infections in the internal hold out sample in the Generation R Study (R2incremental = 0.049), it did not replicate in ALSPAC (R2incremental = 0.001), and it did not prospectively associate with offspring health outcomes in either cohort. Moreover, we observed no association between prenatal exposure to infections and epigenetic age acceleration across cohorts and clocks.

CONCLUSION

In contrast to prior studies, which reported DNAm differences in offspring exposed to severe infections in utero, we do not find evidence for associations between self-reported clinically evident common infections during pregnancy and DNAm or epigenetic aging in cord blood within the general pediatric population. Future studies are needed to establish whether associations exist but are too subtle to be statistically meaningful with present sample sizes, whether they replicate in a cohort with a more similar infection score as our discovery cohort, whether they occur in different tissues than cord blood, and whether other biological pathways may be more relevant for mediating the effect of prenatal common infection exposure on downstream offspring health outcomes.

Associations of childhood BMI, general and visceral fat mass with metabolite profiles at school-age

BACKGROUND

Childhood obesity increases metabolic disease risk. Underlying mechanisms remain unknown. We examined associations of body mass index (BMI), total body fat mass, and visceral fat mass with serum metabolites at school-age, and explored whether identified metabolites improved the identification of children at risk of a metabolically unhealthy phenotype.

METHODS

We performed a cross-sectional analysis among 497 children with a mean age of 9.8 (95% range 9.1, 10.6) years, participating in a population-based cohort study. We measured BMI, total body fat mass using DXA, and visceral fat mass using MRI. Serum concentrations of amino-acids, non-esterified-fatty-acids, phospholipids, and carnitines were determined using LC-MS/MS. Children were categorized as metabolically healthy or metabolically unhealthy, according to BMI, blood pressure, lipids, glucose, and insulin levels.

RESULTS

Higher BMI and total body fat mass were associated with altered concentrations of branched-chain amino-acids, essential amino-acids, and free carnitines. Higher BMI was also associated with higher concentrations of aromatic amino-acids and alkyl-lysophosphatidylcholines (FDR-corrected p-values < 0.05). The strongest associations were present for Lyso.PC.a.C14.0 and SM.a.C32.2 (FDR-corrected p-values < 0.01). Higher visceral fat mass was only associated with higher concentrations of 6 individual metabolites, particularly Lyso.PC.a.C14.0, PC.aa.C32.1, and SM.a.C32.2. We selected 15 metabolites that improved the prediction of a metabolically unhealthy phenotype, compared to BMI only (AUC: BMI: 0.59 [95% CI 0.47,0.71], BMI + Metabolites: 0.91 [95% CI 0.85,0.97]).

CONCLUSIONS

An adverse childhood body fat profile, characterized by higher BMI and total body fat mass, is associated with metabolic alterations, particularly in amino acids, phospholipids, and carnitines. Fewer associations were present for visceral fat mass. We identified a metabolite profile that improved the identification of impaired cardiometabolic health in children, compared to BMI only.

Prenatal exposure to non-persistent chemicals and fetal-to-childhood growth trajectories

INTRODUCTION

Prenatal exposure to non-persistent chemicals, including organophosphate pesticides, phthalates, and bisphenols, is associated with altered fetal and childhood growth. Few studies have examined these associations using longitudinal growth trajectories or considering exposure to chemical mixtures.

METHODS

Among 777 participants from the Generation R Study, we used growth mixture models to identify weight and body mass index (BMI) trajectories using weight and height measures collected from the prenatal period to age 13. We measured exposure biomarkers for organophosphate pesticides, phthalates, and bisphenols in maternal urine at three timepoints during pregnancy. Multinomial logistic regression was used to estimate associations between averaged exposure biomarker concentrations and growth trajectories. We used quantile g-computation to estimate joint associations with growth trajectories.

RESULTS

Phthalic acid (OR: 1.4, 95% CI: 1.01, 1.9) and bisphenol A (BPA; OR: 1.5, 95% CI: 1.0, 2.2) were associated with higher odds of a growth trajectory characterized by smaller prenatal and larger childhood weight relative to a referent trajectory of larger prenatal and average childhood weight. Biomarkers of organophosphate pesticides, individually and jointly, were associated with lower odds of a growth trajectory characterized by average prenatal and lower childhood weight.

CONCLUSIONS

Exposure to phthalates and BPA was positively associated with a weight trajectory characterized by lower prenatal and higher childhood weight, while exposure to organophosphate pesticides was negatively associated with a trajectory of average prenatal and lower childhood weight. This study is consistent with the hypothesis that non-persistent chemical exposures disrupt growth trajectories from the prenatal period through childhood.

Inflammatory markers in pregnancy - surprisingly stable. Mapping trajectories and drivers in four large cohorts

Adaptations of the immune system throughout gestation have been proposed as important mechanisms regulating successful pregnancy. Dysregulation of the maternal immune system has been associated with adverse maternal and fetal outcomes. To translate findings from mechanistic preclinical studies to human pregnancies, studies of serum immune markers are the mainstay. The design and interpretation of human biomarker studies require additional insights in the trajectories and drivers of peripheral immune markers. The current study mapped maternal inflammatory markers (C-reactive protein (CRP), interleukin (IL)-1β, IL-6, IL-17A, IL-23, interferon- γ ) during pregnancy and investigated the impact of demographic, environmental and genetic drivers on maternal inflammatory marker levels in four multi-ethnic and socio-economically diverse population-based cohorts with more than 12,000 pregnant participants. Additionally, pregnancy inflammatory markers were compared to pre-pregnancy levels. Cytokines showed a high correlation with each other, but not with CRP. Inflammatory marker levels showed high variability between individuals, yet high concordance within an individual over time during and pre-pregnancy. Pre-pregnancy body mass index (BMI) explained more than 9.6% of the variance in CRP, but less than 1% of the variance in cytokines. The polygenic score of CRP was the best predictor of variance in CRP (>14.1%). Gestational age and previously identified inflammation drivers, including tobacco use and parity, explained less than 1% of variance in both cytokines and CRP. Our findings corroborate differential underlying regulatory mechanisms of CRP and cytokines and are suggestive of an individual inflammatory marker baseline which is, in part, genetically driven. While prior research has mainly focused on immune marker changes throughout pregnancy, our study suggests that this field could benefit from a focus on intra-individual factors, including metabolic and genetic components.

What makes clocks tick? Characterizing developmental dynamics of adult epigenetic clock sites

DNA methylation (DNAm) at specific sites can be used to calculate 'epigenetic clocks', which in adulthood are used as indicators of age(ing). However, little is known about how these clock sites 'behave' during development and what factors influence their variability in early life. This knowledge could be used to optimize healthy aging well before the onset of age-related conditions. Here, we leveraged results from two longitudinal population-based cohorts (N=5,019 samples from 2,348 individuals) to characterize trajectories of adult clock sites from birth to early adulthood. We find that clock sites (i) diverge widely in their developmental trajectories, often showing non-linear change over time; (ii) are substantially more likely than non-clock sites to vary between individuals already from birth, differences that are predictive of DNAm variation at later ages; and (iii) show enrichment for genetic and prenatal environmental exposures, supporting an early-origins perspective to epigenetic aging.

Eye Size and Shape in Relation to Refractive Error in Children: A Magnetic Resonance Imaging Study

Purpose

The purpose of this study was to determine the association between eye shape and volume measured with magnetic resonance imaging (MRI) and optical biometry and with spherical equivalent (SE) in children.

Methods

For this study, there were 3637 10-year-old children from a population-based birth-cohort study that underwent optical biometry (IOL-master 500) and T2-weighted MRI scanning (height, width, and volume). Cycloplegic refractive error was determined by automated refraction. The MRI images of the eyes were segmented using an automated algorithm combining atlas registration with voxel classification. Associations among optical biometry, anthropometry, MRI measurements, and RE were tested using Pearson correlation. Differences between refractive error groups were tested using ANOVA.

Results

The mean volume of the posterior segment was 6350 (±680) mm3. Myopic eyes (SE ≤ -0.5 diopters [D]) had 470 mm3 (P < 0.001) and 970 mm3 (P < 0.001) larger posterior segment volume than emmetropic and hyperopic eyes (SE ≥ +2.0D), respectively. The majority of eyes (77.1%) had an oblate shape, but 47.4% of myopic eyes had a prolate shape versus 3.9% of hyperopic eyes. The correlation between SE and MRI-derived posterior segment length (r -0.51, P < 0.001) was stronger than the correlation with height (r -0.30, P < 0.001) or width of the eye (r -0.10, P < 0.001).

Conclusions

In this study, eye shape at 10 years of age was predominantly oblate, even in eyes with myopia. Of all MRI measurements, posterior segment length was most prominently associated with SE. Whether eye shape predicts future myopia development or progression should be investigated in longitudinal studies.

Maternal caffeine consumption during pregnancy and offspring cord blood DNA methylation: an epigenome-wide association study meta-analysis

Background: Prenatal caffeine exposure may influence offspring health via DNA methylation, but no large studies have tested this. Materials & methods: Epigenome-wide association studies and differentially methylated regions in cord blood (450k or EPIC Illumina arrays) were meta-analyzed across six European cohorts (n = 3725). Differential methylation related to self-reported caffeine intake (mg/day) from coffee, tea and cola was compared with assess whether caffeine is driving effects. Results: One CpG site (cg19370043, PRRX1) was associated with caffeine and another (cg14591243, STAG1) with cola intake. A total of 12-22 differentially methylated regions were detected with limited overlap across caffeinated beverages. Conclusion: We found little evidence to support an intrauterine effect of caffeine on offspring DNA methylation. Statistical power limitations may have impacted our findings.

Prenatal exposure to common plasticizers: a longitudinal study on phthalates, brain volumetric measures, and IQ in youth

Exposure to phthalates, used as plasticizers and solvents in consumer products, is ubiquitous. Despite growing concerns regarding their neurotoxicity, brain differences associated with gestational exposure to phthalates are understudied. We included 775 mother-child pairs from Generation R, a population-based pediatric neuroimaging study with prenatal recruitment, who had data on maternal gestational phthalate levels and T1-weighted magnetic resonance imaging in children at age 10 years. Maternal urinary concentrations of phthalate metabolites were measured at early, mid-, and late pregnancy. Child IQ was assessed at age 14 years. We investigated the extent to which prenatal exposure to phthalates is associated with brain volumetric measures and whether brain structural measures mediate the association of prenatal phthalate exposure with IQ. We found that higher maternal concentrations of monoethyl phthalate (mEP, averaged across pregnancy) were associated with smaller total gray matter volumes in offspring at age 10 years (β per log10 increase in creatinine adjusted mEP = -10.7, 95%CI: -18.12, -3.28). Total gray matter volumes partially mediated the association between higher maternal mEP and lower child IQ (β for mediated path =-0.31, 95%CI: -0.62, 0.01, p = 0.05, proportion mediated = 18%). An association of higher monoisobutyl phthalate (mIBP) and smaller cerebral white matter volumes was present only in girls, with cerebral white matter volumes mediating the association between higher maternal mIBP and lower IQ in girls. Our findings suggest the global impact of prenatal phthalate exposure on brain volumetric measures that extends into adolescence and underlies less optimal cognitive development.

Fetal Organophosphate Pesticide Exposure and Child Adiposity Measures at 10 Years of Age in the General Dutch Population

BACKGROUND

Fetal exposure to organophosphate (OP) pesticides might lead to fetal metabolic adaptations, predisposing individuals to adverse metabolic profiles in later life.

OBJECTIVE

We examined the association of maternal urinary OP pesticide metabolite concentrations in pregnancy with offspring body mass index (BMI) and fat measures at 10 years of age.

METHODS

Between 2002 and 2006, we included 642 mother-child pairs from the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. We measured maternal urinary concentrations of OP pesticide metabolites, namely, dialkyl phosphates, including three dimethyl and three diethyl phosphates in early-, mid- and late-pregnancy. At 10 years of age, child total and regional body fat and lean mass were measured through dual energy X-ray absorptiometry, and abdominal and organ fat through magnetic resonance imaging.

RESULTS

Higher maternal urinary pregnancy-average or trimester-specific dialkyl, dimethyl, or diethyl phosphate concentrations were not associated with childhood BMI and the risk of overweight. In addition, we did not observe any association of dialkyl, dimethyl, or diethyl phosphate concentrations with total and regional body fat, abdominal visceral fat, liver fat, or pericardial fat at child age of 10 y.

CONCLUSION

We observed no associations of maternal urinary dialkyl concentrations during pregnancy with childhood adiposity measures at 10 years of age. Whether these associations develop at older ages should be further studied. https://doi.org/10.1289/EHP12267.

The ORIGINS Project Biobank: A Collaborative Bio Resource for Investigating the Developmental Origins of Health and Disease

Early onset Non-Communicable Diseases (NCDs), including obesity, allergies, and mental ill-health in childhood, present a serious and increasing threat to lifelong health and longevity. The ORGINS Project (ORIGINS) addresses the urgent need for multidisciplinary efforts to understand the detrimental multisystem impacts of modern environments using well-curated large-scale longitudinal biological sample collections. ORGINS is a prospective community birth cohort aiming to enrol 10,000 pregnant people and follow each family until the children reach 5 years of age. A key objective is to generate a comprehensive biorepository on a sub-group of 4000 families invited to contribute blood, saliva, buccal cells, urine, stool, hair, house dust, cord blood, placenta, amniotic fluid, meconium, breastmilk, and colostrum over eight timepoints spanning the antenatal period and early childhood. Uniquely, ORIGINS includes a series of nested sub-projects, including interventions and clinical trials addressing different aspects of health. While this adds complexity as the project expands, it provides the opportunity for comparative studies. This research design promotes a multidisciplinary, multisystem approach to biological sample collection, analysis, and data sharing to ensure more integrated perspectives and solutions. This paper details the evolving protocol of our collaborative biobanking concept. Further, we outline our future visions for local, national, and ultimately international, comparative, and collaborative opportunities to advance our understanding of early onset NCDs and the opportunities to improve health outcomes for future generations.

Anti-tissue transglutaminase antibodies (TG2A) positivity and the risk of vitamin D deficiency among children - a cross-sectional study in the generation R cohort

BACKGROUND

Suboptimal vitamin D status is common in people with celiac disease (CeD), a disease that can be characterized by the presence of serum anti-tissue transglutaminase antibodies (TG2A) (i.e., TG2A positivity). To date, it remains unclear whether childhood TG2A positivity is associated with vitamin D status and how this potential association can be explained by other factors than malabsorption only, since vitamin D is mainly derived from exposure to sunlight. The aim of our study was therefore to assess whether childhood TG2A positivity is associated with vitamin D concentrations, and if so, to what extent this association can be explained by sociodemographic and lifestyle factors.

METHODS

This cross-sectional study was embedded in the Generation R Study, a population-based prospective cohort. We measured serum anti-tissue transglutaminase antibodies (TG2A) concentrations and serum 25-hydroxyvitamin D (25(OH)D) concentrations of 3994 children (median age of 5.9 years). Children with serum TG2A concentrations ≥ 7 U/mL were considered TG2A positive. To examine associations between TG2A positivity and 25(OH)D concentrations, we performed multivariable linear regression, adjusted for sociodemographic and lifestyle factors.

RESULTS

Vitamin D deficiency (serum 25(OH)D < 50 nmol/L) was found in 17 out of 54 TG2A positive children (31.5%), as compared to 1182 out of 3940 TG2A negative children (30.0%). Furthermore, TG2A positivity was not associated with 25(OH)D concentrations (β -2.20; 95% CI -9.72;5.33 for TG2A positive vs. TG2A negative children), and this did not change after adjustment for confounders (β -1.73, 95% CI -8.31;4.85).

CONCLUSIONS

Our findings suggest there is no association between TG2A positivity and suboptimal vitamin D status in the general pediatric population. However, the overall prevalence of vitamin D deficiency in both populations was high, suggesting that screening for vitamin D deficiency among children, regardless of TG2A positivity, would be beneficial to ensure early dietary intervention if needed.

Myopia risk behaviour related to the COVID-19 lockdown in Europe: The generation R study

PURPOSE

To battle the spreading of the COVID-19 virus, nationwide lockdowns were implemented during 2020 and 2021. Reports from China revealed that their strict home confinements led to an increase in myopia incidence. The Netherlands implemented a more lenient lockdown, which allowed children to go outside. We evaluated the association between COVID-19 restrictions, myopia risk behaviour and myopia progression in Dutch teenagers.

METHOD

A total of 1101 participants (mean age 16.3 ± 3.65 yrs) completed questionnaires about their activities before, during and after lockdown (March-October 2020). We used a repeated-measures ANOVA to compare time use between these time periods. Ocular measurements were acquired before the COVID-19 pandemic when participants were 13 years old; only 242 participants had ocular measurements at 18 years of age at the time of this analysis. Linear regression analyses were used to evaluate the association between lifestyle factors and myopia progression.

RESULTS

Children were on average 16.2 (1.03) years of age during lockdown. Total nearwork increased from 8.11 h/day to 11.79 h/day, and remained higher after lockdown at 9.46 h/day (p < 0.001). Non-educational nearwork increased by 2.22 h/day (+49%) during lockdown and was associated with faster axial length progression (B 0.002 mm/h/year; SE 0.001 p = 0.03). Before and during lockdown, the mean time spent outdoors was similar (1.78 h/day and 1.80 h/day, respectively). After lockdown, time spent outdoors decreased to 1.56 h/day (p < 0.001).

CONCLUSION

The Dutch lockdown significantly increased digitised nearwork in adolescents but did not affect outdoor exposure. The changes in time spent performing nearwork remained after the lockdown measures had ended. We expect that the COVID-19 pandemic may lead to an increase in myopia prevalence and progression in European children.

Maternal lipid levels in early pregnancy as a predictor of childhood lipid levels: a prospective cohort study

Background

Maternal lipid levels in early pregnancy are associated with maternal health and foetal growth. It is however unclear if maternal lipids in early pregnancy can be used to predict childhood lipid levels. The aim of this study is to assess the association between maternal and offspring childhood lipid levels, and to investigate the influence of maternal BMI and diet on these associations.

Methods

This study included 2692 women participating in the Generation R study, an ongoing population-based prospective cohort study from early life onwards. Women with an expected delivery date between 2002 and 2006 living in Rotterdam, the Netherlands were included. Total cholesterol, triglycerides and high-density lipoprotein cholesterol (HDL-c) were measured in early pregnancy (median 13.2 weeks [90% range 10.6; 17.1]). Low-density lipoprotein cholesterol (LDL-c), remnant cholesterol and non-HDL-c were calculated. Corresponding lipid measurements were determined in 2692 children at the age of 6 (median 6.0 years [90% range 5.7; 7.5]) and 1673 children 10 years (median 9.7 years [90% range 9.5; 10.3]). Multivariate linear regression analysis was used to examine the association between maternal lipid levels in early pregnancy and the corresponding childhood lipid measurements at the ages of 6 and 10 years while adjusting for confounders.

Results

Maternal lipid levels in early pregnancy are positively associated with corresponding childhood lipid levels 6 and 10 years after pregnancy, independent of maternal body mass index and diet.

Conclusions

Maternal lipid levels in early pregnancy may provide an insight to the lipid profile of children years later. Gestational lipid levels may therefore be used as an early predictor of children’s long-term health. Monitoring of these gestational lipid levels may give a window-of-opportunity to start early interventions to decrease offspring’s lipid levels and possibly diminish their cardiovascular risk later in life. Future studies are warranted to investigate the genetic contribution on maternal lipid levels in pregnancy and lipid levels of their offspring years later.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04905-7.

Maternal plasma fatty acid patterns in mid-pregnancy and offspring epigenetic gestational age at birth

Maternal pregnancy fatty acid status is associated with child health. Epigenetic gestational age acceleration, referring to a discrepancy between chronological and epigenetic gestational age, may underlie these associations. Previous research suggests that analysing fatty acid patterns rather than individual fatty acids may overcome the caveat of missing synergistic or additive effects. Among 1226 mother-newborn pairs from the population-based Generation R Study, we examined the associations of three maternal plasma mid-pregnancy fatty acid patterns, identified by principal component analysis, with offspring epigenetic gestational age acceleration. This was estimated from cord blood DNA methylation data using the method developed by Bohlin. As a secondary analysis, we used the method developed by Knight to estimate epigenetic gestational age. The identified 'high n-6 polyunsaturated fatty acid,' 'monounsaturated and saturated fatty acid' and 'high n-3 polyunsaturated fatty acid' patterns were not associated with epigenetic gestational age acceleration in the main analyses. In sensitivity analyses restricted to 337 children born to mothers with more accurate pregnancy dating based on a regular menstrual cycle, a one standard-deviation-score higher maternal plasma 'high n-3 polyunsaturated fatty acid' pattern was associated with an epigenetic gestational age acceleration of 0.20 weeks (95% CI 0.06, 0.33), but only when using the Knight method. Thus, we found some evidence that a maternal plasma fatty acid pattern characterized by higher concentrations of n-3 polyunsaturated fatty acids may be associated with accelerated epigenetic gestational ageing. These findings depended on the method used and the accuracy of pregnancy dating and therefore need confirmation.

Maternal Cardiovascular Health in Early Pregnancy and Childhood Brain Structure

Background Poor cardiovascular health during pregnancy has been associated with adverse neurocognitive outcomes in the offspring. We examined the associations of maternal cardiovascular health factors with brain structure in 10-year-old children. Methods and Results We included 2797 mother-offspring pairs from the Generation R Study. Maternal body mass index, gestational weight gain, blood pressure, insulin, glucose, and lipid blood concentrations were obtained in early pregnancy. Childhood structural brain measures, including global metrics of brain tissue volumes and white matter microstructure, were quantified by magnetic resonance imaging at 10 years. As compared with offspring of mothers with normal weight, those of mothers with underweight had smaller total brain volume (difference, -28.99 [95% CI -56.55 to -1.45] cm³). Similarly, as compared with offspring of mothers with gestational weight gain between the 25th and 75th percentile, those of mothers with gestational weight loss or no gestational weight gain (<25th percentile), had smaller total brain volume (difference, -13.07 [95% CI, -23.82 to -2.32] cm³). Also, higher maternal diastolic blood pressure in early pregnancy was associated with lower offspring white matter mean diffusivity (difference, -0.07 [95% CI, -0.11 to -0.02] SD score). After multiple testing correction, only the association of maternal diastolic blood pressure with lower offspring white matter mean diffusivity remained statistically significant. No associations were observed of maternal insulin, glucose, and lipid concentrations with childhood brain outcomes. Conclusions Our findings suggest that maternal cardiovascular health during pregnancy might be related to offspring brain development in the long term. Future studies are needed to replicate our findings and to explore the causal nature of the associations.

Longitudinal Household Assessment of Respiratory Illness in Children and Parents During the COVID-19 Pandemic

IMPORTANCE

In the early COVID-19 pandemic, SARS-CoV-2 testing was only accessible and recommended for symptomatic persons or adults. This restriction hampered assessment of the true incidence of SARS-CoV-2 infection in children as well as detailed characterization of the SARS-CoV-2 disease spectrum and how this spectrum compared with that of other common respiratory illnesses.

OBJECTIVE

To estimate the community incidence of SARS-CoV-2 infection in children and parents and to assess the symptoms and symptom severity of respiratory illness episodes involving SARS-CoV-2-positive test results relative to those with SARS-CoV-2-negative test results.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study randomly selected Dutch households with at least 1 child younger than 18 years. A total of 1209 children and adults from 307 households were prospectively followed up between August 25, 2020, and July 29, 2021, covering the second and third waves of the COVID-19 pandemic. Participation included SARS-CoV-2 screening at 4- to 6-week intervals during the first 23 weeks of participation (core study period; August 25, 2020, to July 29, 2021). Participants in all households finishing the core study before July 1, 2021, were invited to participate in the extended follow-up and to actively report respiratory symptoms using an interactive app until July 1, 2021. At new onset of respiratory symptoms or a SARS-CoV-2 positive test result, a household outbreak study was initiated, which included daily symptom recording, repeated polymerase chain reaction testing (nose-throat swabs and saliva and fecal samples), and SARS-CoV-2 antibody measurement (paired dried blood spots) in all household members. Outbreaks, households, and episodes of respiratory illness were described as positive or negative depending on SARS-CoV-2 test results. Data on participant race and ethnicity were not reported because they were not uniformly collected in the original cohorts and were therefore not representative or informative.

EXPOSURES

SARS-CoV-2-positive and SARS-CoV-2-negative respiratory illness episodes.

MAIN OUTCOMES AND MEASURES

Age-stratified incidence rates, symptoms, and symptom severity for SARS-CoV-2-positive and SARS-CoV-2-negative respiratory illness episodes.

RESULTS

Among 307 households including 1209 participants (638 female [52.8%]; 403 [33.3%] aged <12 years, 179 [14.8%] aged 12-17 years, and 627 [51.9%] aged ≥18 years), 183 household outbreaks of respiratory illness were observed during the core study and extended follow-up period, of which 63 (34.4%) were SARS-CoV-2 positive (59 outbreaks [32.2%] during the core study and 4 outbreaks [2.2%] during follow-up). SARS-CoV-2 incidence was similar across all ages (0.24/person-year [PY]; 95% CI, 0.21-0.28/PY). Overall, 33 of 134 confirmed SARS-CoV-2 episodes (24.6%) were asymptomatic. The incidence of SARS-CoV-2-negative respiratory illness episodes was highest in children younger than 12 years (0.94/PY; 95% CI, 0.89-0.97/PY). When comparing SARS-CoV-2-positive vs SARS-CoV-2-negative respiratory illness episodes in children younger than 12 years, no differences were observed in number of symptoms (median [IQR], 2 [2-4] for both groups), symptom severity (median [IQR] maximum symptom severity score, 6 [4-9] vs 7 [6-13]), or symptom duration (median [IQR], 6 [5-12] days vs 8 [4-13] days). However, among adults, SARS-CoV-2-positive episodes had a significantly higher number (median [IQR], 6 [4-8] vs 3 [2-4]), severity (median [IQR] maximum symptom severity score, 15 [9-19] vs 7 [6-11]), and duration (median [IQR] 13 [8-29] days vs 5 [3-11] days; P < .001 for all comparisons) of symptoms vs SARS-CoV-2-negative episodes.

CONCLUSIONS AND RELEVANCE

In this cohort study, during the first pandemic year when mostly partial or full in-person learning occurred, the SARS-CoV-2 incidence rate in children was substantially higher than estimated from routine testing or seroprevalence data and was similar to that of adult household members. Unlike in unvaccinated adults, SARS-CoV-2 symptoms and symptom severity in children were similar to other common respiratory illnesses. These findings may prove useful when developing pediatric COVID-19 vaccine recommendations.

Epigenetic profiling of social communication trajectories and co-occurring mental health problems: a prospective, methylome-wide association study

While previous studies suggest that both genetic and environmental factors play an important role in the development of autism-related traits, little is known about potential biological mechanisms underlying these associations. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), we examined prospective associations between DNA methylation (DNAm: n_birth = 804, n_{age 7} = 877) and trajectories of social communication deficits at age 8-17 years. Methylomic variation at three loci across the genome (false discovery rate = 0.048) differentiated children following high (n = 80) versus low (n = 724) trajectories of social communication deficits. This differential DNAm was specific to the neonatal period and not observed at 7 years of age. Associations between DNAm and trajectory membership remained robust after controlling for co-occurring mental health problems (i.e., hyperactivity/inattention, conduct problems). The three loci identified at birth were not replicated in the Generation R Study. However, to the best of our knowledge, ALSPAC is the only study to date that is prospective enough to examine DNAm in relation to longitudinal trajectories of social communication deficits from childhood to adolescence. Although the present findings might point to potentially novel sites that differentiate between a high versus low trajectory of social communication deficits, the results should be considered tentative until further replicated.

Axial Length Distributions in Patients With Genetically Confirmed Inherited Retinal Diseases

Purpose

We investigated axial length (AL) distributions in inherited retinal diseases (IRDs), comparing them with reference cohorts.

Methods

AL measurements from IRD natural history study participants were included and compared with reference cohorts (TwinsUK, Raine Study Gen2-20, and published studies). Comparing with the Raine Study cohort, formal odds ratios (ORs) for AL ≥ 26 mm or AL ≤ 22 mm were derived for each IRD (Firth's logistic regression model, adjusted for age and sex).

Results

Measurements were available for 435 patients (median age, 19.5 years). Of 19 diseases, 10 had >10 participants: ABCA4 retinopathy; CNGB3- and CNGA3-associated achromatopsia; RPGR-associated disease; RPE65-associated disease; blue cone monochromacy (BCM); Bornholm eye disease (BED); TYR- and OCA2-associated oculocutaneous albinism; and GPR143-associated ocular albinism. Compared with the TwinsUK cohort (n = 322; median age, 65.1 years) and Raine Study cohort (n = 1335; median age, 19.9 years), AL distributions were wider in the IRD groups. Increased odds for longer ALs were observed for BCM, BED, RPGR, RPE65, OCA2, and TYR; increased odds for short AL were observed for RPE65, TYR, and GPR143. In subanalysis of RPGR-associated disease, longer average ALs occurred in cone-rod dystrophy (n = 5) than rod-cone dystrophy (P = 0.002).

Conclusions

Several diseases showed increased odds for longer AL (highest OR with BCM); some showed increased odds for shorter AL (highest OR with GPR143). Patients with RPE65- and TYR-associated disease showed increased odds for longer and for shorter eyes. Albinism genes were associated with different effects on AL. These findings add to the phenotype of IRDs and may yield insights into mechanisms of refractive error development.

Maternal early-pregnancy ferritin and offspring neurodevelopment: A prospective cohort study from gestation to school age

BACKGROUND

Iron plays a role in many key processes in the developing brain. During pregnancy, iron supplementation is widely recommended to prevent and treat iron deficiency; however, the prevalence of iron deficiency and the risk of iron overload vary greatly between populations. Evidence on the role of high levels of maternal ferritin, a storage iron marker during pregnancy in relation to offspring neurodevelopment is lacking.

OBJECTIVE

Our main objective was to examine if maternal ferritin levels during pregnancy are associated with child cognitive and motor abilities.

METHODS

We included Dutch mother-child dyads from the prospective population-based Generation R Study, born in 2002-2006. We compared children whose mothers had high (standard deviation score >+1) or low (standard deviation score <-1) early-pregnancy ferritin to children whose mothers had intermediate ferritin (reference group) using linear regression. Children underwent non-verbal intelligence and language tests at 4-9 years (cognitive abilities), finger-tapping and balancing tests at 8-12 years (motor abilities), and structural magnetic resonance imaging at 8-12 years (brain morphology). Covariates were child age, sex, maternal intelligence quotient estimate, age, body-mass-index, education, parity, smoking and alcohol use.

RESULTS

Of the 2479 mother-child dyads with data on maternal ferritin and at least one child neurodevelopmental outcome, 387 mothers had low (mean = 20.6 µg/L), 1700 intermediate (mean = 64.6 µg/L) and 392 high (mean = 170.3 µg/L) early-pregnancy ferritin. High maternal ferritin was associated with 2.54 points (95% confidence interval -4.16, -0.92) lower child intelligence quotient and 16.02 cm³ (95% confidence interval -30.57, -1.48) smaller brain volume. Results remained similar after excluding mothers with high C-reactive protein. Low maternal ferritin was not associated with child cognitive abilities. Maternal ferritin was unrelated to child motor outcomes.

CONCLUSION

High maternal ferritin during pregnancy was associated with poorer child cognitive abilities and smaller brain volume. Maternal iron status during pregnancy may be associated with offspring neurodevelopment.

Maternal lipid profile in pregnancy and embryonic size: a population-based prospective cohort study

Background

Lipids are crucial for fetal growth and development. Maternal lipid concentrations are associated with fetal growth in the second and third trimester of pregnancy and with birth outcomes. However, it is unknown if this association starts early in pregnancy or arises later during fetal development. The aim of this study was to investigate the association between the maternal lipid profile in early pregnancy and embryonic size.

Methods

We included 1474 women from the Generation R Study, a population based prospective birth cohort. Both embryonic size and the maternal lipid profile were measured between 10 weeks + 1 day and 13 weeks + 6 days gestational age. The maternal lipid profile was defined as total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), remnant cholesterol, non-high-density (non-HDL-c) lipoprotein cholesterol concentrations and the triglycerides/high-density lipoprotein (TG/HDL-c) ratio. Additionally, maternal glucose concentrations were assessed. Embryonic size was assessed using crown-rump length (CRL) measurements. Associations were studied with linear regression models, adjusted for confounding factors: maternal age, pre-pregnancy body mass index (BMI), parity, educational level, ethnicity, smoking and folic acid supplement use.

Results

Triglycerides and remnant cholesterol concentrations are positively associated with embryonic size (fully adjusted models, 0.17 SDS CRL: 95% CI 0.03; 0.30, and 0.17 SDS: 95% CI 0.04; 0.31 per 1 MoM increase, respectively). These associations were not present in women with normal weight (triglycerides and remnant cholesterol: fully adjusted model, 0.44 SDS: 95% CI 0.15; 0.72). Associations between maternal lipid concentrations and embryonic size were not attenuated after adjustment for glucose concentrations. Total cholesterol, HDL-c, LDL-c, non-HDL-c concentrations and the TG/HDL-c ratio were not associated with embryonic size.

Conclusions

Higher triglycerides and remnant cholesterol concentrations in early pregnancy are associated with increased embryonic size, most notably in overweight women.

Trial registration

The study protocol has been approved by the Medical Ethics Committee of the Erasmus University Medical Centre (Erasmus MC), Rotterdam (MEC-2007-413). Written informed consent was obtained from all participants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04647-6.

Preconception and early-pregnancy risk prediction for birth complications: development of prediction models within a population-based prospective cohort

Background

Suboptimal maternal health already from preconception onwards is strongly linked to an increased risk of birth complications. To enable identification of women at risk of birth complications, we aimed to develop a prediction model for birth complications using maternal preconception socio-demographic, lifestyle, medical history and early-pregnancy clinical characteristics in a general population.

Methods

In a population-based prospective cohort study among 8340 women, we obtained information on 33 maternal characteristics at study enrolment in early-pregnancy. These characteristics covered the preconception period and first half of pregnancy (< 21 weeks gestation). Preterm birth was < 37 weeks gestation. Small-for-gestational-age (SGA) and large-for-gestational-age (LGA) at birth were gestational-age-adjusted birthweight in the lowest or highest decile, respectively. Because of their co-occurrence, preterm birth and SGA were combined into a composite outcome.

Results

The basic preconception model included easy obtainable maternal characteristics in the preconception period including age, ethnicity, parity, body mass index and smoking. This basic preconception model had an area under the receiver operating characteristics curve (AUC) of 0.63 (95% confidence interval (CI) 0.61 to 0.65) and 0.64 (95% CI 0.62 to 0.66) for preterm birth/SGA and LGA, respectively. Further extension to more complex models by adding maternal socio-demographic, lifestyle, medical history and early-pregnancy clinical characteristics led to small, statistically significant improved models. The full model for prediction of preterm birth/SGA had an AUC 0.66 (95% CI 0.64 to 0.67) with a sensitivity of 22% at a 90% specificity. The full model for prediction of LGA had an AUC of 0.67 (95% CI 0.65 to 0.69) with sensitivity of 28% at a 90% specificity. The developed models had a reasonable level of calibration within highly different socio-economic subsets of our population and predictive performance for various secondary maternal, delivery and neonatal complications was better than for primary outcomes.

Conclusions

Prediction of birth complications is limited when using maternal preconception and early-pregnancy characteristics, which can easily be obtained in clinical practice. Further improvement of the developed models and subsequent external validation is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04497-2.

Associations of maternal and infant metabolite profiles with foetal growth and the odds of adverse birth outcomes

BACKGROUND

Adaptations in maternal and foetal metabolic pathways may predispose to altered foetal growth and adverse birth outcomes.

OBJECTIVE

To assess the associations of maternal early-pregnancy metabolite profiles and infant metabolite profiles at birth with foetal growth from first trimester onwards and the odds of adverse birth outcomes.

METHODS

In a prospective population-based cohort among 976 Dutch pregnant women and their children, serum concentrations of amino acids, non-esterified fatty acids (NEFA), phospholipids (PL) and carnitines in maternal early-pregnancy blood and in cord blood were obtained by liquid-chromatography tandem mass spectrometry. Information on foetal growth was available from first trimester onwards.

RESULTS

After false discovery rate correction for multiple testing, higher infant total and individual NEFA concentrations were associated with a lower weight, length, and head circumference at birth. Higher infant total and individual acyl-lysophosphatidylcholine (lyso.PC.a) and alkyl-lysophosphatidylcholine concentrations were associated with higher weight and head circumference (lyso.PC.a only) at birth, higher odds of LGA and lower odds of SGA. Few individual maternal metabolites were associated with foetal growth measures in third trimester and at birth, but not with the odds of adverse birth outcomes.

CONCLUSIONS

Our results suggest that infant metabolite profiles, particularly total and individual lyso.PC.a and NEFA concentrations, were strongly related to growth measures at birth and the odds of adverse birth outcomes. Few individual maternal early-pregnancy metabolites, but not total metabolite concentrations, are associated with foetal growth measures in third trimester and at birth.

Bridging gaps between images and data: a systematic update on imaging biobanks

BACKGROUND AND OBJECTIVE

The systematic collection of medical images combined with imaging biomarkers and patient non-imaging data is the core concept of imaging biobanks, a key element for fuelling the development of modern precision medicine. Our purpose is to review the existing image repositories fulfilling the criteria for imaging biobanks.

METHODS

Pubmed, Scopus and Web of Science were searched for articles published in English from January 2010 to July 2021 using a combination of the terms: "imaging" AND "biobanks" and "imaging" AND "repository". Moreover, the Community Research and Development Information Service (CORDIS) database ( https://cordis.europa.eu/projects ) was searched using the terms: "imaging" AND "biobanks", also including collections, projects, project deliverables, project publications and programmes.

RESULTS

Of 9272 articles retrieved, only 54 related to biobanks containing imaging data were finally selected, of which 33 were disease-oriented (61.1%) and 21 population-based (38.9%). Most imaging biobanks were European (26/54, 48.1%), followed by American biobanks (20/54, 37.0%). Among disease-oriented biobanks, the majority were focused on neurodegenerative (9/33, 27.3%) and oncological diseases (9/33, 27.3%). The number of patients enrolled ranged from 240 to 3,370,929, and the imaging modality most frequently involved was MRI (40/54, 74.1%), followed by CT (20/54, 37.0%), PET (13/54, 24.1%), and ultrasound (12/54, 22.2%). Most biobanks (38/54, 70.4%) were accessible under request.

CONCLUSIONS

Imaging biobanks can serve as a platform for collecting, sharing and analysing medical images integrated with imaging biomarkers, biological and clinical data. A relatively small proportion of current biobanks also contain images and can thus be classified as imaging biobanks.

KEY POINTS

• Imaging biobanks are a powerful tool for large-scale collection and processing of medical images integrated with imaging biomarkers and patient non-imaging data. • Most imaging biobanks retrieved were European, disease-oriented and accessible under user request. • While many biobanks have been developed so far, only a relatively small proportion of them are imaging biobanks.

Sample management: a primary critical starting point for successful omics studies

Biological samples collected from cohort studies are widely utilized in molecular genetic studies and are typically stored long term for future applications, such as omics analyses. The extent of sample availability is determined by proper sample handling, and it is of primary importance for successful omics studies. However, questions on whether samples in long-term storage are properly available for omics experiments has been raised, because the quality and availability of such samples remain unknown until their actual utilization. In that perspective, several guidelines for proper sample management have been suggested. In addition, several researchers assessed how improper management damages sample using mock sample and suggested a set of requirements for sample handling. In this review, we present several considerations for sample handling eligible for omics studies. Focusing on birth cohorts, we describe the types of samples collected from which omics data were generated. This review ultimately aims to provide proper guidelines for sample handling for successful human omics studies.

Stability and Change of Psychopathology Symptoms Throughout Childhood and Adolescence

Assessing stability and change of children's psychopathology symptoms can help elucidate whether specific behaviors are transient developmental variations or indicate persistent psychopathology. This study included 6930 children across early childhood (T1), late childhood (T2) and early adolescence (T3), from the general population. Latent profile analysis identified psychopathology subgroups and latent transition analysis quantified the probability that children remained within, or transitioned across psychopathology subgroups. We identified four psychopathology subgroups; no problems (T1: 85.9%, T2: 79.0%, T3: 78.0%), internalizing (T1: 5.1%, T2: 9.2%, T3: 9.0%), externalizing (T1: 7.3%, T2: 8.3%, T3: 10.2%) and the dysregulation profile (DP) (T1: 1.7%, T2: 3.5%, T3: 2.8%). From T1 to T2, 44.7% of the children remained in the DP. Between T2 and T3, 33.6% remained in the DP; however, 91.4% were classified in one of the psychopathology subgroups. Our findings suggest that for many children, internalizing or externalizing symptoms encompass a transient phase within development. Contrary, the DP resembles a severe at-risk state in which the predictive value for being in one of the psychopathology subgroups increases over time.

Maternal Body Mass Index, Early-Pregnancy Metabolite Profile, and Birthweight

CONTEXT

Maternal prepregnancy body mass index (BMI) has a strong influence on gestational metabolism, but detailed metabolic alterations are unknown.

OBJECTIVE

First, to examine the associations of maternal prepregnancy BMI with maternal early-pregnancy metabolite alterations. Second, to identify an early-pregnancy metabolite profile associated with birthweight in women with a higher prepregnancy BMI that improved prediction of birthweight compared to glucose and lipid concentrations.

DESIGN, SETTING, AND PARTICIPANTS

Prepregnancy BMI was obtained in a subgroup of 682 Dutch pregnant women from the Generation R prospective cohort study.

MAIN OUTCOME MEASURES

Maternal nonfasting targeted amino acids, nonesterified fatty acid, phospholipid, and carnitine concentrations measured in blood serum at mean gestational age of 12.8 weeks. Birthweight was obtained from medical records.

RESULTS

A higher prepregnancy BMI was associated with 72 altered amino acids, nonesterified fatty acid, phospholipid and carnitine concentrations, and 6 metabolite ratios reflecting Krebs cycle, inflammatory, oxidative stress, and lipid metabolic processes (P-values < 0.05). Using penalized regression models, a metabolite profile was selected including 15 metabolites and 4 metabolite ratios based on its association with birthweight in addition to prepregnancy BMI. The adjusted R2 of birthweight was 6.1% for prepregnancy BMI alone, 6.2% after addition of glucose and lipid concentrations, and 12.9% after addition of the metabolite profile.

CONCLUSIONS

A higher maternal prepregnancy BMI was associated with altered maternal early-pregnancy amino acids, nonesterified fatty acids, phospholipids, and carnitines. Using these metabolites, we identified a maternal metabolite profile that improved prediction of birthweight in women with a higher prepregnancy BMI compared to glucose and lipid concentrations.

Prediction of Healthy Pregnancy Outcomes in Women with Overweight and Obesity: The Role of Maternal Early-Pregnancy Metabolites

Women with obesity receive intensified antenatal care due to their increased risk of pregnancy complications, even though not all of these women develop complications. We developed a model based on maternal characteristics for prediction of healthy pregnancy outcomes in women with obesity or who are overweight. We assessed whether early-pregnancy metabolites improved prediction. In a population-based cohort study among a subsample of 1180 Dutch pregnant women with obesity or who are overweight, we developed a prediction model using 32 maternal socio-demographic, lifestyle, physical and pregnancy-related characteristics. We determined early-pregnancy amino acids, nonesterifed fatty acids, phospholipids and carnitines in blood serum using liquid chromatography-tandem mass spectrometry. A healthy pregnancy outcome was the absence of fetal death, gestational hypertension, preeclampsia, gestational diabetes, caesarian section, preterm birth, large-for-gestational-age at birth, macrosomia, postpartum weight retention and offspring overweight/obesity at 5 years. Maternal age, relationship status, parity, early-pregnancy body mass index, mid-pregnancy gestational weight gain, systolic blood pressure and estimated fetal weight were selected into the model using backward selection (area under the receiver operating characteristic curve: 0.65 (95% confidence interval 0.61 to 0.68)). Early-pregnancy metabolites did not improve model performance. Thus, in women with obesity or who are overweight, maternal characteristics can moderately predict a healthy pregnancy outcome. Maternal early-pregnancy metabolites have no incremental value in the prediction of a healthy pregnancy outcome.

Prenatal Exposure to Nonpersistent Chemical Mixtures and Offspring IQ and Emotional and Behavioral Problems

Prenatal exposure to nonpersistent chemicals such as phthalates, bisphenols, and organophosphate (OP) pesticides is ubiquitous and occurs in mixtures. So far, epidemiological studies investigating neurodevelopmental consequences of these exposures have mainly been restricted to single-pollutant models. Thus, we studied the association between prenatal exposure to nonpersistent chemical mixtures and child IQ and emotional and behavioral problems. Data came from 782 mother-child pairs. Eleven phthalate, one bisphenol, and five OP pesticide urinary exposure biomarkers were measured three times during pregnancy and averaged. Nonverbal IQ, internalizing and attention problems, aggressive behavior, and autistic traits were assessed at child age 6 years. We used quantile g-computation to estimate the change in each outcome per quartile increase in all chemicals within the mixture. Higher exposure to the mixture was associated with lower nonverbal IQ (-4.0 points (95%CI = -7.0, -1.0), -5.5 points (95%CI = -10.2, -0.9), and -4.6 points (95%CI = -10.8, 1.5) for the second, third, and fourth quartile, respectively, compared to the first quartile). These results were mainly driven by the phthalate mixture. No association was observed with emotional and behavioral problems. Prenatal exposure to nonpersistent chemical mixtures was associated with lower nonverbal IQ in children. Exposure to chemical mixtures during gestation is universal and may impact neurodevelopment.

Body fat, cardiovascular risk factors and brain structure in school-age children

BACKGROUND

In adults, cardiovascular risk factors are known to be associated with brain health. We hypothesized that these associations are already present at school-age. We examined the associations of adverse body fat measures and cardiovascular risk factors with brain structure, including volumetric measures and white matter microstructure, in 10-year-old children.

METHODS

We performed a cross-sectional analysis in a population-based prospective cohort study in Rotterdam, the Netherlands. Analyses were based on 3098 children aged 10 years with neuroimaging data and at least one measurement of body fat and cardiovascular risk factors. Body fat measures included body mass index (BMI), fat mass index and android fat mass percentage obtained by Dual-energy X-ray absorptiometry. Cardiovascular risk factors included blood pressure, and serum glucose, insulin and lipids blood concentrations. Structural neuroimaging, including global and regional brain volumes, was quantified by magnetic resonance imaging. DTI was used to assess white matter microstructure, including global fractional anisotropy (FA) and mean diffusivity (MD).

RESULTS

As compared to children with a normal weight, those with underweight had a smaller total brain and white matter volumes (differences -18.10 (95% Confidence Interval (CI) -30.97,-5.22) cm³, -10.64 (95% CI -16.82,-4.47) cm³, respectively). In contrast, one SDS (Standard Deviation Score) increase in fat mass index was associated with a smaller gray matter volume (differences -3.48 (95% CI -16.82, -4.47) cm³). Also, one SDS increase in android fat mass percentage was associated with lower white matter diffusivity (difference -0.06 (95% CI -0.10, -0.02) SDS). None of the other cardiovascular risk factors were associated with any of the brain outcomes.

CONCLUSIONS

Body fat measures, but not other cardiovascular risk factors, were associated with structural neuroimaging outcomes in school-aged children. Prospective studies are needed to assess causality, direction and long-term consequences of the associations.

Prenatal Exposure to Nonpersistent Chemical Mixtures and Fetal Growth: A Population-Based Study

BACKGROUND

Prenatal exposure to mixtures of nonpersistent chemicals is universal. Most studies examining these chemicals in association with fetal growth have been restricted to single exposure models, ignoring their potentially cumulative impact.

OBJECTIVE

We aimed to assess the association between prenatal exposure to a mixture of phthalates, bisphenols, and organophosphate (OP) pesticides and fetal measures of head circumference, femur length, and weight.

METHODS

Within the Generation R Study, a population-based cohort in Netherlands (n=776), urinary concentrations of 11 phthalate metabolites, 3 bisphenols, and 5 dialkylphosphate (DAP) metabolites were measured at <18, 18-25, and >25 weeks of gestation and averaged. Ultrasound measures of head circumference, femur length, and estimated fetal weight (EFW) were taken at 18-25 and >25 weeks of gestation, and measurements of head circumference, length, and weight were performed at delivery. We estimated the difference in each fetal measurement per quartile increase in all exposures within the mixture with quantile g-computation.

RESULTS

The average EFW at 18-25 wk and >25wk was 369 and 1,626g, respectively, and the average birth weight was 3,451g. Higher exposure was associated with smaller fetal and newborn growth parameters in a nonlinear fashion. At 18-25 wk, fetuses in the second, third, and fourth quartiles of exposure (Q2-Q4) had 26g [95% confidence intervals (CI):-38, -13], 35g (95% CI: -55, -15), and 27g (95% CI: -54, 1) lower EFW compared with those in the first quartile (Q1). A similar dose-response pattern was observed at >25wk, but all effect sizes were smaller, and no association was observed comparing Q4 to Q1. At birth, we observed no differences in weight between Q1-Q2 or Q1-Q3. However, fetuses in Q4 had 91g (95% CI: -258, 76) lower birth weight in comparison with those in Q1. Results observed at 18-25 and >25wk were similar for femur length; however, no differences were observed at birth. No associations were observed for head circumference.

DISCUSSION

Higher exposure to a mixture of phthalates, bisphenols, and OP pesticides was associated with lower EFW in the midpregnancy period. In late pregnancy, these differences were similar but less pronounced. At birth, the only associations observed appeared when comparing individuals from Q1 and Q4. This finding suggests that even low levels of exposure may be sufficient to influence growth in early pregnancy, whereas higher levels may be necessary to affect birth weight. Joint exposure to nonpersistent chemicals may adversely impact fetal growth, and because these exposures are widespread, this impact could be substantial. https://doi.org/10.1289/EHP9178.

Maternal Early-Pregnancy Glucose Concentrations and Liver Fat Among School-Age Children

BACKGROUND AND AIMS

Gestational diabetes seems to be associated with offspring NAFLD. We hypothesized that maternal glucose concentrations across the full range may have persistent effects on offspring liver fat accumulation.

APPROACH AND RESULTS

In a multiethnic, population-based, prospective cohort study among 2,168 women and their offspring, maternal early-pregnancy glucose concentrations were measured at a median of 13.1 weeks' gestation (95% CI, 9.6-17.2). Liver fat fraction was measured at 10 years by MRI. NAFLD was defined as liver fat fraction ≥5.0%. We performed analyses among all mothers with different ethnic backgrounds and those of European ancestry only. The multiethnic group had a median maternal early-pregnancy glucose concentration of 4.3 mmol/L (interquartile range, 3.9-4.9) and a 2.8% (n = 60) prevalence of NAFLD. The models adjusted for child age and sex only showed that in the multiethnic group, higher maternal early-pregnancy glucose concentrations were associated with higher liver fat accumulation and higher odds of NAFLD, but these associations attenuated into nonsignificance after adjustment for potential confounders. Among mothers of European ancestry only, maternal early-pregnancy glucose concentrations were associated with increased odds of NAFLD (OR, 1.95; 95% CI, 1.32; 2.88, after adjustment for confounders) per 1-mmol/L increase in maternal early-pregnancy glucose concentration. These associations were not explained by maternal prepregnancy and childhood body mass index, visceral fat, and metabolic markers.

CONCLUSIONS

In this study, maternal early-pregnancy glucose concentrations were only among mothers of European ancestry associated with offspring NAFLD. The associations of higher maternal early-pregnancy glucose concentrations with offspring NAFLD may differ between ethnic groups.

Diet quality and cardiometabolic health in childhood: the Generation R Study

Purpose

Diet is an important determinant of cardiometabolic disease risk in adults. We aimed to study associations of diet quality with cardiometabolic health in school-age children.

Methods

This study was embedded in the Generation R Study a prospective population-based cohort in Rotterdam, the Netherlands and included 3991 children. Food intake was assessed with a Food-Frequency Questionnaire at age 8 years. A diet quality score (0–10) was calculated reflecting adherence to age-specific dietary guidelines. The following outcome variables were measured at age 10 years and used to create a continuous cardiometabolic risk factor score: body fat percentage, insulin, triglycerides, HDL cholesterol, and systolic and diastolic blood pressure. Outcomes were expressed in age- and sex-specific standard deviation scores (SDS). Multivariable linear regression models were used to assess associations between the diet quality score and the cardiometabolic risk factor score and with the individual cardiometabolic risk factors.

Results

In models adjusted for socioeconomic and lifestyle factors and BMI, a higher diet quality was associated with a lower cardiometabolic risk factor score [− 0.08 per point higher diet score, (95% CI − 0.15, − 0.001)]. This association was mainly driven by associations of higher diet quality with lower systolic [− 0.04 SD (95% CI − 0.06, − 0.01)] and diastolic blood pressure [− 0.05 SD, (95% CI − 0.07, − 0.02)]. No statistically significant associations were found for insulin, triglycerides, HDL cholesterol, or body fat percentage as individual factors.

Conclusions

We found an association between higher diet quality and better cardiometabolic health in childhood, mainly driven by a lower blood pressure. Further research is needed to explore associations of diet quality in childhood with long-term cardiometabolic health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02673-2.

Associations of Hair Cortisol Concentrations With Cardiometabolic Risk Factors in Childhood

CONTEXT

Biological stress is related to cardiovascular disease in adults. The associations of stress with cardiovascular and metabolic diseases may originate in childhood.

OBJECTIVE

This work aims to examine the associations of hair cortisol concentrations at age 6 years with cardiometabolic risk factors at ages 6 and 10 years.

METHODS

Cortisol concentrations were measured in hair of 6-year-old children (n = 2598) participating in the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. Main outcome measures included blood pressure, heart rate, concentrations of insulin, glucose, lipids, and C-reactive protein in blood at ages 6 and 10 years.

RESULTS

Higher hair cortisol concentrations at age 6 years were associated with higher systolic blood pressure at age 10 years (difference 0.17 SD score; 95% CI, 0.03-0.31). The association attenuated into nonsignificance after adjustment for childhood body mass index (BMI) at age 6 years. Higher hair cortisol concentrations at age 6 years were associated with an increase in total and low-density lipoprotein cholesterol between ages 6 and 10 years but not with those measurements at age 6 or 10 years. Hair cortisol concentrations were not associated with other cardiometabolic risk factors at age 6 or 10 years.

CONCLUSION

Hair cortisol concentrations were not independent of BMI associated with cardiometabolic risk factors at 6 or 10 years. The associations of biological stress with cardiometabolic risk factors may develop at later ages.

Phenotypic Consequences of the GJD2 Risk Genotype in Myopia Development

Purpose

To study the relatively high effect of the refractive error gene GJD2 in human myopia, and to assess its relationship with refractive error, ocular biometry and lifestyle in various age groups.

Methods

The population-based Rotterdam Study (RS), high myopia case-control study MYopia STudy, and the birth-cohort study Generation R were included in this study. Spherical equivalent (SER), axial length (AL), axial length/corneal radius (AL/CR), vitreous depth (VD), and anterior chamber depth (ACD) were measured using standard ophthalmologic procedures. Biometric measurements were compared between GJD2 (rs524952) genotype groups; education and environmental risk score (ERS) were calculated to estimate gene-environment interaction effects, using the Synergy index (SI).

Results

RS adults carrying two risk alleles had a lower SER and longer AL, ACD and VD (AA versus TT, 0.23D vs. 0.70D; 23.79 mm vs. 23.52 mm; 2.72 mm vs. 2.65 mm; 16.12 mm vs. 15.87 mm; all P < 0.001). Children carrying two risk alleles had larger AL/CR at ages 6 and 9 years (2.88 vs. 2.87 and 3.00 vs. 2.96; all P < 0.001). Education and ERS both negatively influenced myopia and the biometric outcomes, but gene-environment interactions did not reach statistical significance (SI 1.25 [95% confidence interval {CI}, 0.85-1.85] and 1.17 [95% CI, 0.55-2.50] in adults and children).

Conclusions

The elongation of the eye caused by the GJD2 risk genotype follows a dose-response pattern already visible at the age of 6 years. These early effects are an example of how a common myopia gene may drive myopia.

Smartphone Use Associated with Refractive Error in Teenagers: The Myopia App Study

PURPOSE

To investigate the association between smartphone use and refractive error in teenagers using the Myopia app.

DESIGN

Cross-sectional population-based study.

PARTICIPANTS

A total of 525 teenagers 12 to 16 years of age from 6 secondary schools and from the birth cohort study Generation R participated.

METHODS

A smartphone application (Myopia app; Innovattic) was designed to measure smartphone use and face-to-screen distance objectively and to pose questions about outdoor exposure. Participants underwent cycloplegic refractive error and ocular biometry measurements. Mean daily smartphone use was calculated in hours per day and continuous use as the number of episodes of 20 minutes on screen without breaks. Linear mixed models were conducted with smartphone use, continuous use, and face-to-screen distance as determinants and spherical equivalent of refraction (SER) and axial length-to-corneal radius (AL:CR) ratio as outcome measures stratified by median outdoor exposure.

MAIN OUTCOME MEASURES

Spherical equivalent of refraction in diopters and AL:CR ratio.

RESULTS

The teenagers on average were 13.7 ± 0.85 years of age, and myopia prevalence was 18.9%. During school days, total smartphone use on average was 3.71 ± 1.70 hours/day and was associated only borderline significantly with AL:CR ratio (β = 0.008; 95% confidence interval [CI], -0.001 to 0.017) and not with SER. Continuous use on average was 6.42 ± 4.36 episodes of 20-minute use without breaks per day and was associated significantly with SER and AL:CR ratio (β = -0.07 [95% CI, -0.13 to -0.01] and β = 0.004 [95% CI, 0.001-0.008], respectively). When stratifying for outdoor exposure, continuous use remained significant only for teenagers with low exposure (β = -0.10 [95% CI, -0.20 to -0.01] and β = 0.007 [95% CI, 0.001-0.013] for SER and AL:CR ratio, respectively). Smartphone use during weekends was not associated significantly with SER and AL:CR ratio, nor was face-to-screen distance.

CONCLUSIONS

Dutch teenagers spent almost 4 hours per day on their smartphones. Episodes of 20 minutes of continuous use were associated with more myopic refractive errors, particularly in those with low outdoor exposure. This study suggested that frequent breaks should become a recommendation for smartphone use in teenagers. Future large longitudinal studies will allow more detailed information on safe screen use in youth.

Maternal First-Trimester Cow-Milk Intake Is Positively Associated with Childhood General and Abdominal Visceral Fat Mass and Lean Mass but Not with Other Cardiometabolic Risk Factors at the Age of 10 Years

BACKGROUND

Higher maternal cow-milk intake during pregnancy is associated with higher fetal growth measures and higher birth weight.

OBJECTIVE

The aim of this study was to assess the associations of maternal milk intake during pregnancy with body fat measures and cardiometabolic risk factors at the age of 10 y.

METHODS

In a population-based cohort of Dutch mothers and their children (n = 2466) followed from early pregnancy onwards, we assessed maternal first-trimester milk intake (milk and milk drinks) by food-frequency questionnaire. Maternal milk intake was categorized into 0-0.9, 1-1.9, 2-2.9, 3-3.9, 4-4.9, and ≥5 glasses/d, with 1 glass equivalent to 150 mL milk. For children at the age of 10 y, we calculated BMI and obtained detailed measures of body and organ fat by DXA and MRI. We also measured blood pressure and lipid, insulin, and glucose concentrations. Data were analyzed using linear and logistic regression models.

RESULTS

Compared with children whose mothers consumed 0-0.9 glass of milk/d during their pregnancy, those whose mothers consumed ≥5 glasses of milk/d had a 0.29 SD (95% CI: 0.10, 0.48) higher BMI, 0.27 SD (95% CI: 0.08, 0.47) higher fat mass, 0.26 SD (95% CI: 0.07, 0.46) higher lean mass, 0.30 SD (95% CI: 0.09, 0.50) higher android-to-gynoid fat mass ratio and 0.38 SD (95% CI: 0.09, 0.67) higher abdominal visceral fat mass. After correction for multiple comparisons, groups of maternal milk intake were not associated with pericardial fat mass index, liver fat fraction, blood pressure, or lipid, insulin, or glucose concentrations (P values >0.0125).

CONCLUSIONS

Our results suggest that maternal first-trimester milk intake is positively associated with childhood general and abdominal visceral fat mass and lean mass, but not with other cardiometabolic risk factors.

Maternal iron status during early pregnancy and school-age, lung function, asthma, and allergy: The Generation R Study

BACKGROUND

Iron deficiency during early life could affect the developing lung and immune system, and influence child's respiratory or allergy outcomes in later life.

OBJECTIVE

To examine the associations of maternal iron status during early pregnancy with child's lung function, asthma, inhalant allergic sensitization, and physician-diagnosed inhalant allergy at school-age.

METHODS

In a population-based cohort study, among 3825 mother-child pairs, ferritin, transferrin concentrations, and transferrin saturation were measured from maternal venous blood samples during early pregnancy. In children at the age of 10 years, spirometry was used to determine child's lung function, current asthma and physician-diagnosed inhalant allergy were assessed by questionnaires, and inhalant allergic sensitization was measured by skin prick tests. We used multivariable regression models to examine the associations.

RESULTS

After adjustment for gestational age at maternal iron status measurement and sociodemographic or lifestyle-related confounders, a higher maternal transferrin concentration was associated with a higher risk of physician-diagnosed inhalant allergy (odds ratio [95% confidence interval]: 1.13 [1.01 to1.26]), but not with lung function, asthma, or inhalant allergic sensitization. This association did not attenuate after further adjustment for maternal hemoglobin levels or early growth factors. We observed no consistent association of maternal ferritin concentrations or transferrin saturation with child's respiratory or allergy outcomes.

CONCLUSION

Higher maternal transferrin concentrations during pregnancy, reflecting lower serum iron levels, were associated with an increased risk of child's physician-diagnosed inhalant allergy but not lung outcomes. Underlying mechanisms and clinical implications need to be explored.

DNA methylation signatures of aggression and closely related constructs: A meta-analysis of epigenome-wide studies across the lifespan

DNA methylation profiles of aggressive behavior may capture lifetime cumulative effects of genetic, stochastic, and environmental influences associated with aggression. Here, we report the first large meta-analysis of epigenome-wide association studies (EWAS) of aggressive behavior (N = 15,324 participants). In peripheral blood samples of 14,434 participants from 18 cohorts with mean ages ranging from 7 to 68 years, 13 methylation sites were significantly associated with aggression (alpha = 1.2 × 10-7; Bonferroni correction). In cord blood samples of 2425 children from five cohorts with aggression assessed at mean ages ranging from 4 to 7 years, 83% of these sites showed the same direction of association with childhood aggression (r = 0.74, p = 0.006) but no epigenome-wide significant sites were found. Top-sites (48 at a false discovery rate of 5% in the peripheral blood meta-analysis or in a combined meta-analysis of peripheral blood and cord blood) have been associated with chemical exposures, smoking, cognition, metabolic traits, and genetic variation (mQTLs). Three genes whose expression levels were associated with top-sites were previously linked to schizophrenia and general risk tolerance. At six CpGs, DNA methylation variation in blood mirrors variation in the brain. On average 44% (range = 3-82%) of the aggression-methylation association was explained by current and former smoking and BMI. These findings point at loci that are sensitive to chemical exposures with potential implications for neuronal functions. We hope these results to be a starting point for studies leading to applications as peripheral biomarkers and to reveal causal relationships with aggression and related traits.

Application of the Instrumental Inequalities to a Mendelian Randomization Study With Multiple Proposed Instruments

Supplemental Digital Content is available in the text.

Investigators often support the validity of Mendelian randomization (MR) studies, an instrumental variable approach proposing genetic variants as instruments, via. subject matter knowledge. However, the instrumental variable model implies certain inequalities, offering an empirical method of falsifying (but not verifying) the underlying assumptions. Although these inequalities are said to detect only extreme assumption violations in practice, to our knowledge they have not been used in settings with multiple proposed instruments.

The association of maternal folic acid supplementation and prenatal folate and vitamin B12 concentrations with child dental development

OBJECTIVE

Low folic acid, folate and vitamin B12 might affect tooth formation and mineralization. The conversion of folic acid into folate is catalysed by the methylenetetrahydrofolate (MTHFR) enzyme which is encoded by the MTHFR gene. Among 3728 mothers and their 10-year-old children from the Generation R Study, we investigated associations of maternal folic acid supplementation and prenatal folate and vitamin B12 concentrations with child dental development. Secondly, we checked the modifying effect of MTHFR-C677T polymorphism.

METHODS

Information on folic acid supplementation was obtained by questionnaires. Concentrations of folate and vitamin B12 were measured from venous samples taken in early pregnancy. Developmental stages of teeth were defined by the Demirjian method at the age-10 assessment. In addition, dental age of the children was calculated using the Dutch standard. GLM and multivariate linear regression models were built to study the associations.

RESULTS

Folic acid supplementation started when pregnancy was known (β = -0.09; 95% CI: -0.17, -0.01) and folic acid supplementation started prior to known pregnancy (β = -0.12; 95% CI: -0.20, -0.04) were both associated with decelerated dental development by 1-2 months lower dental age of 10-year-old children. Folate (β = -0.02, 95% CI: -0.05, 0.02) and vitamin B12 (β = 0.03, 95% CI: -0.00, 0.06) were not associated with dental age. MTHFR-C677T did not modify the associations.

CONCLUSIONS

Maternal folic acid supplementation delays dental development of children by 1-2 months dental age, whereas maternal folate and vitamin B12 concentrations in early pregnancy do not affect the timing of child dental development.

Gestational lipid profile as an early marker of metabolic syndrome in later life: a population-based prospective cohort study

BACKGROUND

In pregnancy lipid levels increase with gestation resembling an atherogenic lipid profile. Currently it is unclear whether gestational lipid levels are associated with an adverse cardiovascular risk profile later in life. The aim of this study is to assess the association between gestational lipid levels and lipid levels and prevalence of the metabolic syndrome (MS) six years after pregnancy.

METHODS

In plasma of 3510 women from the Generation R Study; a prospective population-based cohort, we measured lipid levels (total cholesterol, triglycerides and high-density lipoprotein cholesterol [HDL-c]), and low-density lipoprotein cholesterol (LDL-c), remnant cholesterol and non-HDL-c were calculated in early pregnancy (median 13.2 weeks, 90% range [10.5 to 17.1]) and six years after pregnancy (median 6.5 years, 90% range [6.2 to 7.8]). MS was assessed six years after pregnancy according to the NCEP/ATP3 criteria. We also examined the influence of pregnancy complications on these associations.

RESULTS

Gestational lipid levels were positively associated with corresponding lipid levels six years after pregnancy, independent of pregnancy complications. Six years after pregnancy the prevalence of MS was 10.0%; the prevalence was higher for women with a previous placental syndrome (13.5%). Gestational triglycerides and remnant cholesterol in the highest quartile and HDL-c in the lowest quartile were associated with the highest risk for future MS, independent of smoking and body mass index.

CONCLUSIONS

Gestational lipid levels provide an insight in the future cardiovascular risk profile of women in later life. Monitoring and lifestyle intervention could be indicated in women with an unfavorable gestational lipid profile to optimize timely cardiovascular risk prevention.

Design and overview of the Origins of Alzheimer's Disease Across the Life course (ORACLE) study

Brain development and deterioration across the lifespan are integral to the etiology of late-life neurodegenerative disease. Factors that influence the health of the adult brain remain to be elucidated and include risk factors, protective factors, and factors related to cognitive and brain reserve. To address this knowledge gap we designed a life-course study on brain health, which received funding through the EU ERC Programme under the name Origins of Alzheimer’s Disease Across the Life course (ORACLE) Study. The ORACLE Study is embedded within Generation R, a prospective population-based cohort study of children and their parents, and links this with the Rotterdam Study, a population-based study in middle-aged and elderly persons. The studies are based in Rotterdam, the Netherlands. Generation R focuses on child health from fetal life until adolescence with repeated in-person examinations, but has also included data collection on the children’s parents. The ORACLE Study aims to extend the parental data collection in nearly 2000 parents with extensive measures on brain health, including neuroimaging, cognitive testing and motor testing. Additionally, questionnaires on migraine, depressive symptoms, sleep, and neurological family history were completed. These data allow for the investigation of longitudinal influences on adult brain health as well as intergenerational designs involving children and parents. As a secondary focus, the sampling is enriched by mothers (n = 356) that suffered from hypertensive disorders during pregnancy in order to study brain health in this high-risk population. This article provides an overview of the rationale and the design of the ORACLE Study.

Associations of maternal metabolic profile with placental and fetal cerebral and cardiac hemodynamics

OBJECTIVE

Maternal obesity and metabolic health affect pregnancy outcomes. We examined whether maternal metabolic profiles are associated with placental and fetal hemodynamics.

STUDY DESIGN

In a population-based prospective cohort study among 1175 women we examined the associations of an adverse maternal metabolic profile in early pregnancy with placental, fetal cerebral and cardiac hemodynamic development. We obtained maternal pre-pregnancy BMI by questionnaire and measured blood pressure, cholesterol, triglycerides and glucose concentrations at a median gestational age of 12.6 (95 % range 9.6-17.1) weeks. An adverse maternal metabolic profile was defined as ≥4 risk factors. Placental and fetal hemodynamics were measured by pulsed-wave-Doppler at a median gestational age of 30.3 (95 % range 28.8-32.3) weeks.

RESULTS

An adverse maternal metabolic profile was associated with a 0.29 Z-score higher (95 %CI 0.08-0.50) fetal cerebral middle artery pulsatility index (PI), but not with placental or fetal cardiac hemodynamic patterns. When the individual components of an adverse maternal metabolic profile were assessed, we observed that higher maternal total cholesterol and triglyceride concentrations were associated with a higher cerebral middle artery PI (Z-score, 0.09 (95 %CI 0.02-0.15), 0.09 (95 %CI 0.03-0.15) per Z-score increase). Higher total and HDL maternal cholesterol concentrations were also associated with a higher aorta ascendens peak systolic velocity (PSV) Z-score, 0.08 (95 %CI 0.01-0.14)), and a larger left cardiac output (Z-score, 0.08 (95 %CI 0.00-0.15), respectively).

CONCLUSION

An adverse maternal metabolic profile, especially higher cholesterol and triglycerides concentrations, are associated with increased fetal cerebral vascular resistance and larger fetal aorta ascendens diameter, PSV and left cardiac output, but not with placental vascular resistance indices. Further studies are needed to identify long-term consequences of the observed associations.

Fetal phthalates and bisphenols and childhood lipid and glucose metabolism. A population-based prospective cohort study

BACKGROUND AND AIMS

Fetal exposure to endocrine disruptors such as phthalates and bisphenols may lead to developmental metabolic adaptations. We examined associations of maternal phthalate and bisphenol urine concentrations during pregnancy with lipids, insulin, and glucose concentrations at school age.

METHODS

In a population-based, prospective cohort study among 757 mother-child pairs, we measured maternal phthalate and bisphenol urine concentrations in first, second and third trimester of pregnancy. We measured non-fasting lipids, glucose and insulin blood concentrations of their children at a mean age of 9.7 (standard deviation 0.2) years. Analyses were performed for boys and girls separately.

RESULTS

An interquartile range (IQR) higher natural log transformed third trimester maternal urine phthalic acid concentration was associated with a 0.20 (95% confidence interval (CI) 0.07-0.34) standard deviation score (SDS) higher triglycerides concentration among boys. Maternal bisphenol urine concentrations were not associated with non-fasting lipid concentrations during childhood. An IQR higher natural log transformed second trimester maternal high molecular weight phthalates (HMWP) and di-2-ethylhexylphthalate (DEHP) urine concentration were associated with a 0.19 (95% CI 0.31-0.07) respectively 0.18 (95% CI 0.31-0.06) SDS lower glucose concentration among boys. An IQR higher natural log transformed third trimester maternal bisphenol F urine concentration was associated with a 0.22 (95% CI 0.35-0.09) SDS lower non-fasting insulin concentration among boys.

CONCLUSIONS

Our results suggest potential persisting sex specific effects of fetal exposure to phthalates and bisphenols on childhood lipid concentrations and glucose metabolism. Future studies are needed for replication and exploring underlying mechanisms.

Associations of Plasma Fatty Acid Patterns during Pregnancy with Respiratory and Allergy Outcomes at School Age

Fatty acids might play a role in asthma and allergy development as they can modulate immune responses. We examined among 4260 mother-child pairs participating in a population-based cohort the associations of maternal plasma fatty acid patterns during pregnancy with a child's respiratory and allergy outcomes at school-age. In mid-pregnancy, 22 individual fatty acids were measured from maternal blood. Three patterns were previously identified by principal component analysis: A 'high n-6 polyunsaturated fatty acid (PUFA)', a 'monounsaturated and saturated fatty acid', and a 'high n-3 PUFA' pattern. At the age of 10 years, a child's lung function was assessed by spirometry, current asthma and physician-diagnosed inhalant allergy by questionnaire, and inhalant allergic sensitization by skin prick tests. A higher 'high n-6 PUFA' pattern was associated with a higher forced expiratory volume in 1 s/forced vital capacity and forced expiratory flow after exhaling 75% of forced vital capacity (Z-score difference (95% CI) 0.04 (0, 0.07) and 0.04 (0.01, 0.07), respectively, per SD increase in the fatty acid pattern). We observed no associations of maternal fatty acid patterns with a child's asthma or allergy outcomes. Our results showed limited associations of maternal patterns of high n-6 PUFA concentrations in pregnancy with a better lung function in school-aged children.

Maternal lipid profile in early pregnancy is associated with foetal growth and the risk of a child born large-for-gestational age: a population-based prospective cohort study : Maternal lipid profile in early pregnancy and foetal growth

BACKGROUND

Lipids such as cholesterol and triglycerides play an important role in both maternal and foetal energy metabolism. Little is known about maternal lipid levels in pregnancy and their effect on foetal growth. The aim of this study was to assess maternal lipid levels, foetal growth and the risk of small-for-gestational age (SGA) and large-for-gestational age (LGA).

METHODS

We included 5702 women from the Generation R Study, a prospective population-based cohort. Maternal lipid levels (total cholesterol, triglycerides and high-density lipoprotein cholesterol [HDL-c]) were measured in early pregnancy (median 13.4 weeks, 90% range [10.5 to 17.2]). Low-density lipoprotein cholesterol (LDL-c), remnant cholesterol and non-HDL-c were calculated. Foetal growth was measured repeatedly by ultrasound. Information on birth anthropometrics was retrieved from medical records. A birth weight below the 10th percentile was defined as SGA and above the 90th percentile as LGA.

RESULTS

Maternal triglyceride and remnant cholesterol levels were associated with increased foetal head circumference and abdominal circumference growth rates. Triglycerides and remnant cholesterol were positively associated with the risk of LGA (odds ratio [OR] 1.11, 95% confidence interval [CI] [1.01 to 1.22] and OR 1.11, 95% CI [1.01 to 1.23], respectively). These associations were independent of maternal pre-pregnancy body mass index, but not maternal glucose levels. We observed no association between maternal lipids in early pregnancy and SGA.

CONCLUSIONS

Our study suggests a novel association of early pregnancy triglyceride and remnant cholesterol levels with foetal growth, patterns of foetal growth and the risk of LGA. Future studies are warranted to explore clinical implication possibilities.

Associations of maternal early-pregnancy blood glucose and insulin concentrations with DNA methylation in newborns

BACKGROUND

Intrauterine exposure to a disturbed maternal glucose metabolism is associated with adverse offspring outcomes. DNA methylation is a potential mechanism underlying these associations. We examined whether maternal early-pregnancy glucose and insulin concentrations are associated with newborn DNA methylation. In a population-based prospective cohort study among 935 pregnant women, maternal plasma concentrations of non-fasting glucose and insulin were measured at a median of 13.1 weeks of gestation (95% range 9.4-17.4). DNA methylation was measured using the Infinium HumanMethylation450 BeadChip (Ilumina). We analyzed associations of maternal early-pregnancy glucose and insulin concentrations with single-CpG DNA methylation using robust linear regression models. Differentially methylated regions were analyzed using the dmrff package in R. We stratified the analyses on normal weight versus overweight or obese women. We also performed a look-up of CpGs and differently methylated regions from previous studies to be associated with maternal gestational diabetes, hyperglycemia or hyperinsulinemia, or with type 2 diabetes in adults.

RESULTS

Maternal early-pregnancy glucose and insulin concentrations were not associated with DNA methylation at single CpGs nor with differentially methylated regions in the total group. In analyses stratified on maternal BMI, maternal early-pregnancy glucose concentrations were associated with DNA methylation at one CpG (cg03617420, XKR6) among normal weight women and at another (cg12081946, IL17D) among overweight or obese women. No stratum-specific associations were found for maternal early-pregnancy insulin concentrations. The two CpGs were not associated with birth weight or childhood glycemic measures (p values > 0.1). Maternal early-pregnancy insulin concentrations were associated with one CpG known to be related to adult type 2 diabetes. Enrichment among nominally significant findings in our maternal early-pregnancy glucose concentrations was found for CpGs identified in a previous study on adult type 2 diabetes.

CONCLUSIONS

Maternal early-pregnancy glucose concentrations, but not insulin concentrations, were associated with DNA methylation at one CpG each in the subgroups of normal weight and of overweight or obese women. No associations were present in the full group. The role of these CpGs in mechanisms underlying offspring health outcomes needs further study. Future studies should replicate our results in larger samples with early-pregnancy information on maternal fasting glucose metabolism.