Associations of light exposure patterns with sleep among Dutch children: The ABCD cohort study.

Light exposure affects the circadian system and consequently can affect sleep quality. Only few studies examined this relationship in children. We evaluated associations between light exposure patterns and sleep metrics in children. We measured the sleep parameters of 247 Dutch children, aged between 11 and 13 years and recruited from the ABCD cohort, using actigraphy and sleep records for 7 consecutive nights. Personal light exposures were measured with a light meter during the whole day and night. We applied generalized mixed-effects regression models, adjusted for possible confounders, to evaluate the associations of light exposure patterns on sleep duration, sleep efficiency and sleep-onset delay. In the models mutually adjusted for potential confounders, we found the amount of hours between the first time of bright light in the morning and going to sleep and the duration of bright light to be significantly associated with decreased sleep duration (in min; ß: -2.02 [95% confidence interval: -3.84, -0.25], ß: -8.39 [95% confidence interval: -16.70, -0.07], respectively) and with shorter sleep-onset delay (odds ratio: 0.88 [95% confidence interval: 0.80, 0.97], odds ratio: 0.40 [95% confidence interval: 0.19, 0.87], respectively). Increased light intensities at night were associated with decreased sleep duration (T2 ß: -8.54 [95% confidence interval: -16.88, -0.20], T3 ß: -14.83 [95% confidence interval: -28.04, -1.62]), while increased light intensities before going to bed were associated with prolonged sleep onset (odds ratio: 4.02 [95% confidence interval: 2.09, 7.73]). These findings further suggest that children may be able to influence their sleep quality by influencing the light exposure patterns during day and night.

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

AIMS: To examine associations of assisted reproductive technology (ART) conception (vs. natural conception: NC) with offspring cardiometabolic health outcomes and whether these differ with age. METHODS AND RESULTS: Differences in systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), lipids, and hyperglycaemic/insulin resistance markers were examined using multiple linear regression models in 14 population-based birth cohorts in Europe, Australia, and Singapore, and results were combined using meta-analysis. Change in cardiometabolic outcomes from 2 to 26 years was examined using trajectory modelling of four cohorts with repeated measures. 35 938 (654 ART) offspring were included in the meta-analysis. Mean age ranged from 13 months to 27.4 years but was <10 years in 11/14 cohorts. Meta-analysis found no statistical difference (ART minus NC) in SBP (-0.53 mmHg; 95% CI:-1.59 to 0.53), DBP (-0.24 mmHg; -0.83 to 0.35), or HR (0.02 beat/min; -0.91 to 0.94). Total cholesterol (2.59%; 0.10-5.07), HDL cholesterol (4.16%; 2.52-5.81), LDL cholesterol (4.95%; 0.47-9.43) were statistically significantly higher in ART-conceived vs. NC offspring. No statistical difference was seen for triglycerides (TG), glucose, insulin, and glycated haemoglobin. Long-term follow-up of 17 244 (244 ART) births identified statistically significant associations between ART and lower predicted SBP/DBP in childhood, and subtle trajectories to higher SBP and TG in young adulthood; however, most differences were not statistically significant. CONCLUSION: These findings of small and statistically non-significant differences in offspring cardiometabolic outcomes should reassure people receiving ART. Longer-term follow-up is warranted to investigate changes over adulthood in the risks of hypertension, dyslipidaemia, and preclinical and clinical cardiovascular disease.

Early pregnancy triglycerides and not fructosamine are associated with birth weight (with foetal sexual dimorphism).

BACKGROUND: We evaluated whether maternal triglycerides (TGs) or fructosamine (measured in early pregnancy) predominantly contribute to birth weight (BW), in a foetal sexual dimorphism. METHODS: Analysis of data from the Amsterdam Born Children and their Development cohort study (total n = 3514). Maternal nonfasting TGs and fructosamine were determined in early gestation (median 13 weeks). Multivariable linear regression analysis was used to determine whether maternal TGs or fructosamine was associated with BW-small for gestational age (SGA)-large for gestational age (LGA) and whether it was sex-dependent. RESULTS: With each 1 mmol/L increase in TGs, BW increased significantly by 81.7 g. This increase was larger with boys (107.3 g; 95% CI 66-148) than girls (60.5 g; 95% CI 23.6-97.4). No association was found with fructosamine. When including different covariates (gestational age at blood sampling, total duration of pregnancy, maternal height, age, parity, ethnicity, educational level, smoking, alcohol, and pre-pregnancy BMI), 29% of the variance in BW can be explained. Adding fructosamine to this model gave no added value in predicting BW, in contrast to adding TGs (R2 raised from 0.292 to 0.299, p < .001). The odds of a newborn LGA with higher maternal TG were increased (OR 1.6, 95% CI 1.3-2.0), in contrast to fructosamine. CONCLUSIONS: Maternal TGs were more dominant (compared to fructosamine) in its association with BW (measured in early physiological pregnancy) and more prominently present when carrying a male foetus. These remarkable observations warrant more future research, especially in obese patients at risk for gestational diabetes.

Modelling individual infancy growth trajectories to predict excessive gain in BMI z-score: a comparison of growth measures in the ABCD and GECKO Drenthe cohorts.

BACKGROUND: Excessive weight gain during childhood is a strong predictor for adult overweight, but it remains unknown which growth measures in infancy (0-2 years of age), besides predictors known at birth, are the strongest predictors for excessive weight gain between 2 and 5-7 years of age. METHODS: The Amsterdam Born Children and their Development (ABCD) study formed the derivation cohort, and the Groningen Expert Center for Kids with Obesity (GECKO) Drenthe study formed the validation cohort. Change (Δ) in body mass index (BMI) z-score between 2 and 5-7 years was the outcome of interest. The growth measures considered were weight, weight-for-length (WfL), and body mass index (BMI). Formats considered for each growth measure were values at 1, 6, 12, and 24 months, at the BMI peak, the change between aforementioned ages, and prepeak velocity. 10 model structures combining different variable formats and including predictors at birth were derived for each growth measure, resulting in 30 linear regression models. A Parsimonious Model considering all growth measures and a Birth Model considering none were also derived. RESULTS: The derivation cohort consisted of 3139 infants of which 373 (11.9%) had excessive gain in BMI z-score (> 0.67). The validation cohort contained 2201 infants of which 592 (26.9%) had excessive gain. Across the 3 growth measures, 5 model structures which included measures related to the BMI peak and prepeak velocity (derivation cohort area under the curve [AUC] range = 0.765-0.855) achieved more accurate estimates than 3 model structures which included growth measure change over time (0.706-0.795). All model structures which used BMI were superior to those using weight or WfL. The AUC across all models was on average 0.126 lower in the validation cohort. The Parsimonious Model's AUCs in the derivation and validation cohorts were 0.856 and 0.766, respectively, compared to 0.690 and 0.491, respectively, for the Birth Model. The respective false positive rates were 28.2% and 20.1% for the Parsimonious Model and 70.0% and 74.6% for the Birth Model. CONCLUSION: Models' performances varied significantly across model structures and growth measures. Developing the optimal model requires extensive testing of the many possibilities.

Parental Discontent with Infant Sleep During the First Two Years of Life.

BACKGROUND: Problematic sleep in infants can have a high impact on families. We examined parental discontent with infant sleep in the first six months of life and parent-perceived problematic sleep during the second year of life. METHODS: We used Sarphati Cohort data of 1471 children. During periodic youth health care visits in the first six months of life, professionals registered parental discontent with infant sleep. In the second year of life, parents filled out the Brief Infant Sleep Questionnaire (BISQ), from which we defined parent-perceived problematic sleep and BISQ-defined problematic sleep. We examined the association of parental discontent with infant sleep during the first six months with both BISQ-derived outcomes up to age two, using multivariable logistic regression analysis. RESULTS: 26% of parents were discontented with infant sleep during the first six months of life. During the second year of life, 27% of the parents perceived their child's sleep as problematic, and 9% of the infants had BISQ-defined problematic sleep. Early parental discontent with infant sleep was associated with parent-perceived problematic sleep [adjusted OR 2.50 (95% CI 1.91-3.28)], and BISQ-defined problematic sleep [adjusted OR 1.88 (1.11-3.17)]. CONCLUSIONS: Early registered parental discontent with infant sleep was a predictor of parent-perceived problematic sleep in early toddlerhood. Registering parental discontent during infancy might enable professionals to identify a group of infants at risk for later problematic sleep. We recommend screening and parental support for sleep difficulties in an early stage.

Ideal cardiovascular health at age 5-6 years and cardiometabolic outcomes in preadolescence.

BACKGROUND: The American Heart Association (AHA) developed a definition of ideal cardiovascular health (ICH) based on the presence of both ideal health behaviours (diet, physical activity, weight status and smoking) and ideal health factors (glucose, total cholesterol and blood pressure levels). However, research of ICH in the paediatric population is scarce. We aimed to study ICH at age 5-6 years by extending the original ICH score with the health behaviours: sleep duration, screen time and prenatal smoke exposure, and to evaluate its association with cardiometabolic outcomes at age 11-12. METHODS: A total of 1666 children aged 5-6 years were selected from the database of the ABCD-study, a prospective cohort study on the health and development of children born in Amsterdam, the Netherlands. Of these, 846 (50.8%) were boys and 1460 (87.6%) had a healthy weight. Data on self-reported health behaviours and health factors were used to calculate the ICH scores (original and extended) by adding the frequency of scoring 'healthy' on each indicator, based on international cut-offs. The children were followed up for 6 years and cardiometabolic outcomes (carotid intima-media thickness (CIMT), blood pressure, glucose and lipids) were measured. Associations between ICH (both original and extended) and cardiometabolic outcomes were examined using multivariable regression models. RESULTS: At age 5-6 years, 11% scored poor (score 1-5), 56% intermediate (score 6-7) and 33% good (score 8-9) on extended ICH. Healthy diet and normal total cholesterol concentrations were the least prevalent. Neither the original nor the extended ICH scores were associated with CIMT at age 11-12. A higher score on the extended ICH was associated with lower total cholesterol (p for trend < 0.001), lower systolic (p for trend = 0.012) and diastolic blood pressure (p for trend = 0.011), and lower body mass index (BMI) (p < 0.001) at age 11-12. The original ICH score was associated with lower total cholesterol (p < 0.001) and BMI (p < 0.001) only. CONCLUSION: Our findings suggest that extending the ICH score in young children with additional health behaviours improves prediction of some cardiometabolic outcomes, but not CIMT in preadolescence, compared to the original ICH score. We would recommend other researchers to incorporate objective measures of health behaviours and longer follow-up to find out whether associations persist into adulthood.

First trimester employment, working conditions and preterm birth: a prospective population-based cohort study.

OBJECTIVES: To explore the association between working conditions during first trimester and total preterm birth (PTB), and subtypes: spontaneous PTB and iatrogenic PTB, additionally to explore the role of hypertension. METHODS: Pregnant women from the Amsterdam Born Children and their Development study, filled out a questionnaire between January 2003 and March 2004, two weeks after first prenatal screening (singleton liveborn, n=7561). Working conditions were working hours/week, standing/walking hours/week, physical work load and job strain. RESULTS: Prolonged standing/walking during first trimester was associated with an increased risk for total PTB (OR=1.5; 95% CI 1.0-2.3, after adjustments). Other working conditions were not related to total PTB. The separation into spontaneous and iatrogenic PTB revealed that standing/walking was associated with iatrogenic PTB only (OR=2.09; 95% CI 1.00-4.97). The highest risk was found for the combination of a long workweek with high physical work load (OR=3.42; 95% CI 1.04-8.21). Hypertension did not mediate these associations; however, stratified analysis revealed that high physical work load was only related to iatrogenic PTB when pregnancy-induced hypertension was present (OR=6.44; 95% CI 1.21-29.76). CONCLUSION: This study provides evidence that high physically demanding work is associated with an increased risk for iatrogenic PTB and not with spontaneous PTB. Pregnancy-induced hypertension may play a role: when present, high physical work load leads to a more severe outcome.

Radiofrequency electromagnetic fields from mobile communication: Description of modeled dose in brain regions and the body in European children and adolescents.

BACKGROUND: Little is known about radiofrequency electromagnetic fields (RF) from mobile technology and resulting dose in young people. We describe modeled integrated RF dose in European children and adolescents combining own mobile device use and surrounding sources. METHODS: Using an integrated RF model, we estimated the daily RF dose in the brain (whole-brain, cerebellum, frontal lobe, midbrain, occipital lobe, parietal lobe, temporal lobes) and the whole-body in 8358 children (ages 8-12) and adolescents (ages 14-18) from the Netherlands, Spain, and Switzerland during 2012-2016. The integrated model estimated RF dose from near-field sources (digital enhanced communication technology (DECT) phone, mobile phone, tablet, and laptop) and far-field sources (mobile phone base stations via 3D-radiowave modeling or RF measurements). RESULTS: Adolescents were more frequent mobile phone users and experienced higher modeled RF doses in the whole-brain (median 330.4 mJ/kg/day) compared to children (median 81.8 mJ/kg/day). Children spent more time using tablets or laptops compared to adolescents, resulting in higher RF doses in the whole-body (median whole-body dose of 81.8 mJ/kg/day) compared to adolescents (41.9 mJ/kg/day). Among brain regions, temporal lobes received the highest RF dose (medians of 274.9 and 1786.5 mJ/kg/day in children and adolescents, respectively) followed by the frontal lobe. In most children and adolescents, calling on 2G networks was the main contributor to RF dose in the whole-brain (medians of 31.1 and 273.7 mJ/kg/day, respectively). CONCLUSION: This first large study of RF dose to the brain and body of children and adolescents shows that mobile phone calls on 2G networks are the main determinants of brain dose, especially in temporal and frontal lobes, whereas whole-body doses were mostly determined by tablet and laptop use. The modeling of RF doses provides valuable input to epidemiological research and to potential risk management regarding RF exposure in young people.

Psychosocial and peripartum determinants of postpartum depression: Findings from a prospective population-based cohort. The ABCD study.

BACKGROUND: Postpartum depression is prevalent and concerns a serious health problem for women and their families. The current large-scale birth cohort study investigated: (1) the associations of various potential determinants of postpartum depression using a multidimensional approach, and (2) the individual contribution of obstetric and perinatal determinants and pregnancy-specific anxiety to the risk of postpartum depression. METHODS: This study was based on a large-scale birth cohort study in Amsterdam, the Netherlands (ABCD-study). In 5109 women depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (cut-off ≥16 indicating high risk of postpartum depression). Determinants were assessed using self-report or perinatal registries. RESULTS: In the final multivariable model, other-Western and non-Western ethnic background, increased antepartum depressive symptoms, increased antepartum anxiety, increased pregnancy-specific anxiety, being unemployed, poor sleep quality, unwanted pregnancy, abuse, multiparity, and congenital abnormality were all independently related to an increased risk of postpartum depression. The strongest risk factors for postpartum depression were antepartum depressive symptoms (adjusted odds ratio (AOR) = 3.86, 95% confidence interval (CI) 3.02-4.92), having a baby with a congenital abnormality (AOR = 2.33, 95% CI 1.46-3.73), and abuse (AOR = 1.95, 95% CI 1.02-3.73). The final model accounted for 24.5% of the variance. LIMITATIONS: Our dataset did not provide information on social support or maternal and family history of depression. Next to these determinants, future research should include biological factors. CONCLUSIONS: The determinants identified provide opportunities for the development of multidimensional early screening and early intervention strategies for women with an increased risk of postpartum depression.

Feeding patterns and BMI trajectories during infancy: a multi-ethnic, prospective birth cohort.

BACKGROUND: Milk feeding type (exclusive breastfeeding [EBF], formula feeding or mixed feeding) and timing of complementary feeding (CF) have been associated with infant growth. However, studies evaluating their combined role, and the role of ethnicity, are scarce. We examined associations of feeding patterns (milk feeding type combined with timing of CF) with infant body mass index (BMI) trajectories and potential ethnic-specific associations. METHODS: Infant feeding and BMI data during the 1st year of life from 3524 children (Dutch n = 2880, Moroccan n = 404 and Turkish n = 240) from the Amsterdam Born Children and their Development (ABCD) cohort were used. Six feeding patterns were defined: EBF/earlyCF, EBF/lateCF (reference), formula/earlyCF, formula/lateCF, mixed/earlyCF and mixed/lateCF. A covariate adjusted latent class mixed model was applied to simultaneously model BMI trajectories and associations with feeding patterns. Potential ethnic differences in the associations were studied in a separate model where interactions between ethnicity and feeding patterns were included. RESULTS: Four distinct BMI trajectories (low, mid-low, mid-high and high) were identified. Feeding pattern of formula/earlyCF was associated with lower odds for low (OR: 0.43; 95% CI: 0.25, 0.76) or mid-high (0.28; 0.16, 0.51) (ref: high) trajectory compared with EBF/lateCF pattern (ref). An ethnic-specific model revealed that among Dutch infants, formula/earlyCF pattern was associated with lower odds for low trajectory (0.46; 0.24, 0.87), whereas among Turkish/Moroccan infants almost all feeding patterns were associated with lower odds for the low trajectory (ref: high). CONCLUSION: Infant feeding patterns are associated with early BMI trajectories with specific ethnic differences. Future studies should take the role of ethnicity into account in the associations between infant feeding and growth.

Maternal verbal aggression in early infancy and child's internalizing symptoms: interaction by common oxytocin polymorphisms.

Genetic predisposition of social sensitivity might affect vulnerability to develop psychopathology after early life stress exposure. This study examined whether maternal verbally aggressive behavior in early infancy interacts with oxytocin polymorphisms in developing internalizing symptoms at ages 5-6 and 11-12. In the Amsterdam-Born-Children-and-their-Development (ABCD) study, a large observational, population-based birth cohort, maternal verbally aggressive behavior was assessed in the 13th postnatal week by a self-report questionnaire. Internalizing symptoms at age 5-6 were assessed by maternal report (N = 969) and internalizing symptoms at age 11-12 were assessed by self-report (N = 750). Data on oxytocin receptor polymorphisms rs53576 and rs2268498 and oxytocin polymorphisms rs2740210 and rs4813627 were collected. If the child was carrier of rs2740210 CA/AA polymorphism, exposure to maternal verbally aggressive behavior (10.6%) was positively associated with general anxiety at age 5-6 and emotional symptoms at age 11-12 (p for interaction = 0.011 and p = 0.015, respectively). If the child was carrier of rs4813627 GG (wild type), exposure to maternal verbally aggressive behavior was negatively associated with anxiety sensitivity and emotional symptoms at age 11-12 (p for interaction = 0.011 and p = 0.022, respectively). After exposure to maternal verbally aggressive behavior in early infancy, oxytocin polymorphisms may partly determine a child's vulnerability to internalizing symptoms.

Maternal environmental risk factors and the development of internalizing and externalizing problems in childhood: The complex role of genetic factors.

The development of problem behavior in children is associated with exposure to environmental factors, including the maternal environment. Both are influenced by genetic factors, which may also be correlated, that is, environmental risk and problem behavior in children might be influenced by partly the same genetic factors. In addition, environmental and genetic factors could interact with each other increasing the risk of problem behavior in children. To date, limited research investigated these mechanisms in a genome-wide approach. Therefore, the goal of this study was to investigate the association between genetic risk for psychiatric and related traits, as indicated by polygenetic risk scores (PRSs), exposure to previously identified maternal risk factors, and problem behavior in a sample of 1,154 children from the Amsterdam Born Children and their Development study at ages 5-6 and 11-12 years old. The PRSs were derived from genome-wide association studies (GWASs) on schizophrenia, major depressive disorder, neuroticism, and wellbeing. Regression analysis showed that the PRSs were associated with exposure to multiple environmental risk factors, suggesting passive gene-environment correlation. In addition, the PRS based on the schizophrenia GWAS was associated with externalizing behavior problems in children at age 5-6. We did not find any association with problem behavior for the other PRSs. Our results indicate that genetic predispositions for psychiatric disorders and wellbeing are associated with early environmental risk factors for children's problem behavior.

Associations of Maternal Cell-Phone Use During Pregnancy With Pregnancy Duration and Fetal Growth in 4 Birth Cohorts.

Results from studies evaluating potential effects of prenatal exposure to radio-frequency electromagnetic fields from cell phones on birth outcomes have been inconsistent. Using data on 55,507 pregnant women and their children from Denmark (1996-2002), the Netherlands (2003-2004), Spain (2003-2008), and South Korea (2006-2011), we explored whether maternal cell-phone use was associated with pregnancy duration and fetal growth. On the basis of self-reported number of cell-phone calls per day, exposure was grouped as none, low (referent), intermediate, or high. We examined pregnancy duration (gestational age at birth, preterm/postterm birth), fetal growth (birth weight ratio, small/large size for gestational age), and birth weight variables (birth weight, low/high birth weight) and meta-analyzed cohort-specific estimates. The intermediate exposure group had a higher risk of giving birth at a lower gestational age (hazard ratio = 1.04, 95% confidence interval: 1.01, 1.07), and exposure-response relationships were found for shorter pregnancy duration (P < 0.001) and preterm birth (P = 0.003). We observed no association with fetal growth or birth weight. Maternal cell-phone use during pregnancy may be associated with shorter pregnancy duration and increased risk of preterm birth, but these results should be interpreted with caution, since they may reflect stress during pregnancy or other residual confounding rather than a direct effect of cell-phone exposure.

The explanatory role of maternal feeding practices: do they explain ethnic differences in body weight of preadolescents?

INTRODUCTION: This study aimed to explore the role of ethnicity and maternal perceived weight status in the association between maternal child feeding practices and childhood Body Mass Index (BMI) at the age of 11-12 years in a multi-ethnic population. METHODS: We collected data on child feeding practices by the validated Child Feeding Questionnaire (CFQ) among 2398 mothers of adolescents (Mage = 11.2, SDage = 0.6). Multivariate linear analyses were used to determine the cross-sectional association between child feeding practices ('Restriction', 'Pressure to eat', and 'Monitoring'), maternal perception of child's weight status, SDS-BMI, and ethnicity. RESULTS: 'Restriction' (ß = 0.16; 95% CI [0.11; 0.20]) and 'Pressure to eat' (ß = -0.32 [-0.36;-0.28]) were significantly associated with child SDS-BMI. Both associations were strongly influenced by the mother's perception of child's weight status. Besides, non-native Dutch mothers performed significantly higher levels of 'Restriction' (M±SD = 12.17 ±â€¯4.41) and 'Pressure to eat' (10.75 ±â€¯4.03) compared to native Dutch mothers (11.25 ±â€¯4.15 and 9.99 ±â€¯3.83, respectively). Native Dutch mothers performed higher levels of 'Monitoring' (17.15 ±â€¯2.54) compared to non-native Dutch mothers (16.73 ±â€¯3.01). Furthermore, children of non-native Dutch mothers had a 0.15 (0.27; 0.46) higher SDS-BMI. Finally, results showed that the association between 'Pressure to eat' and SDS-BMI was stronger in native Dutch mothers (ß = -0.20; 95% CI [-0.24; -0.15]) compared to non-native Dutch mothers (ß = -0.11; 95% CI [-0.18; -0.04]). DISCUSSION AND CONCLUSION: Ethnic differences in childhood BMI seemed to be partially attributable to the maternal perception of her child's weight status. Besides, maternal perception of child's weight appeared to play an important role in the association between maternal child feeding practices and childhood SDS-BMI. Hence, our findings contribute to the growing evidence concerning the bi-directional association between child feeding practices and childhood BMI.

Does early onset asthma increase childhood obesity risk? A pooled analysis of 16 European cohorts.

The parallel epidemics of childhood asthma and obesity over the past few decades have spurred research into obesity as a risk factor for asthma. However, little is known regarding the role of asthma in obesity incidence. We examined whether early-onset asthma and related phenotypes are associated with the risk of developing obesity in childhood.This study includes 21 130 children born from 1990 to 2008 in Denmark, France, Germany, Greece, Italy, The Netherlands, Spain, Sweden and the UK. We followed non-obese children at 3-4 years of age for incident obesity up to 8 years of age. Physician-diagnosed asthma, wheezing and allergic rhinitis were assessed up to 3-4 years of age.Children with physician-diagnosed asthma had a higher risk for incident obesity than those without asthma (adjusted hazard ratio (aHR) 1.66, 95% CI 1.18-2.33). Children with active asthma (wheeze in the last 12 months and physician-diagnosed asthma) exhibited a higher risk for obesity (aHR 1.98, 95% CI 1.31-3.00) than those without wheeze and asthma. Persistent wheezing was associated with increased risk for incident obesity compared to never wheezers (aHR 1.51, 95% CI 1.08-2.09).Early-onset asthma and wheezing may contribute to an increased risk of developing obesity in later childhood.

Air Pollution Exposure During Pregnancy and Symptoms of Attention Deficit and Hyperactivity Disorder in Children in Europe.

BACKGROUND: Exposure to air pollution during pregnancy may increase attention-deficit/hyperactivity disorder (ADHD) symptoms in children, but findings have been inconsistent. We aimed to study this association in a collaborative study of eight European population-based birth/child cohorts, including 29,127 mother-child pairs. METHODS: Air pollution concentrations (nitrogen dioxide [NO2] and particulate matter [PM]) were estimated at the birth address by land-use regression models based on monitoring campaigns performed between 2008 and 2011. We extrapolated concentrations back in time to exact pregnancy periods. Teachers or parents assessed ADHD symptoms at 3-10 years of age. We classified children as having ADHD symptoms within the borderline/clinical range and within the clinical range using validated cutoffs. We combined all adjusted area-specific effect estimates using random-effects meta-analysis and multiple imputations and applied inverse probability-weighting methods to correct for loss to follow-up. RESULTS: We classified a total of 2,801 children as having ADHD symptoms within the borderline/clinical range, and 1,590 within the clinical range. Exposure to air pollution during pregnancy was not associated with a higher odds of ADHD symptoms within the borderline/clinical range (e.g., adjusted odds ratio [OR] for ADHD symptoms of 0.95, 95% confidence interval [CI] = 0.89, 1.01 per 10 µg/m increase in NO2 and 0.98, 95% CI = 0.80, 1.19 per 5 µg/m increase in PM2.5). We observed similar associations for ADHD within the clinical range. CONCLUSIONS: There was no evidence for an increase in risk of ADHD symptoms with increasing prenatal air pollution levels in children aged 3-10 years. See video abstract at, http://links.lww.com/EDE/B379.

Maternal vitamin D concentrations are associated with faster childhood reaction time and response speed, but not with motor fluency and flexibility, at the age of 5-6 years: the Amsterdam Born Children and their Development (ABCD) Study.

About 57 % of the pregnant European women have 25-hydroxyvitamin D (25(OH)D) concentrations below 50 nmol/l. However, as data on the impact of gestational vitamin D deficiency on maternal and fetal health are limited, the WHO does not advocate vitamin D supplementation as part of routine antenatal care. We explored associations between first trimester maternal 25(OH)D status and childhood cognition at 5-6 years of age (n 1854, primarily Caucasian). Median serum 25(OH)D was determined at 13 (interquartile range 12-14) weeks of gestation. Childhood attention, motor fluency and flexibility and executive function were assessed using the Amsterdam Neuropsychological Tasks. Restricted cubic splines and linear regression analyses were used to analyse the data while adjusting for many maternal and child related covariates. Higher 25(OH)D status (nmol/l) was associated with better attention and executive functioning as shown by a faster reaction time (ß -0·30 (sd 0·14) ms, P=0·03), faster response speed (ß -0·58 (sd 0·21) ms, P=0·006), and better response speed stability (ß -0·45 (sd 0·17) ms, P=0·009). No associations were observed of serum 25(OH)D with motor fluency and flexibility. Associations were most pronounced among children of African origin (n 205) as compared with those of Caucasian or another origin, for example attention (reaction time, ß -2·06 (sd 0·70) ms, P=0·004) and executive function (response speed, ß -1·95 (sd 0·94) ms, P=0·04). Concluding, maternal 25(OH)D status was significantly associated with childhood attention and executive function, while no associations were observed for 25(OH)D status with motor fluency and flexibility.

Association between pre-pregnancy weight status and maternal micronutrient status in early pregnancy.

OBJECTIVE: Inadequate maternal micronutrient status during pregnancy can lead to short- and long-term health risks for mother and offspring. The present study investigated the association between pre-pregnancy weight status and micronutrient status during pregnancy. DESIGN: Maternal blood samples were collected during early pregnancy (median 13, interquartile range 12-15 weeks) and were assayed for serum folate, ferritin, Fe and vitamin B12. Regression modelling was used to assess the association between pre-pregnancy underweight, normal weight, overweight and obesity, and micronutrient levels, as well as the odds for deficiencies. SETTING: The Amsterdam Born Children and their Development (ABCD) study, the Netherlands. SUBJECTS: Women with singleton pregnancies without diabetes (n 4243). RESULTS: After adjustment for covariates, overweight women and obese women had lower (ß; 95 % CI) folate (-1·2; -2·2, -0·2 and -2·3; -4·0, -0·7 nmol/l, respectively) and Fe (-1·7; -2·3, -1·1 and -3·6; -4·7, -2·6 µmol/l, respectively) levels than women with normal weight. Furthermore, overweight women had 6 % (95 % CI -9, -3 %) and obese women had 15 % (-19, -10 %), lower vitamin B12 levels, and obese women had 19 % (6, 32 %) higher ferritin levels, than normal-weight women. Obese women had higher odds (OR; 95 % CI) for folate deficiency (2·03; 1·35, 3·06), Fe deficiency (3·26; 2·09, 5·08) and vitamin B12 deficiency (2·05; 1·41, 2·99) than women with normal weight. Underweight was not associated with micronutrient status. CONCLUSIONS: During early pregnancy, women with pre-pregnancy overweight and obesity had lower serum folate, Fe and vitamin B12 status. This resulted in increased risk of serum folate, Fe and vitamin B12 deficiencies in women with obesity.

Socioeconomic inequalities in psychosocial problems of children: mediating role of maternal depressive symptoms.

Background: Socioeconomically disadvantaged children often have psychosocial problems. This study examined the mediating role of maternal depressive symptoms during pregnancy, infancy and early childhood in the association between maternal education, as indicator of socioeconomic status (SES), and child's psychosocial problems. Methods: Included were 3410 children from the Amsterdam Born Children and their Development (ABCD) study. To assess the child's psychosocial problems at age 5-6 years, mothers and teachers completed the Strengths and Difficulties Questionnaire (SDQ). Maternal depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale and the Depressive Anxiety and Stress Scale 21. Mediation analysis was performed to calculate the direct effect of maternal education on SDQ score and indirect effects through maternal depressive symptoms. Results: The mean mother-reported SDQ total score was significantly higher (P < 0.001) for children of low-educated mothers (6.74 ± 4.41) compared with children of highly educated mothers (4.47 ± 3.73). Levels of maternal depressive symptoms were also higher in low-educated mothers during pregnancy, infancy and early childhood. Maternal depressive symptoms explained 27.5% of the association between maternal education and mother-reported SDQ scores and 22.9% for combined mother/teacher SDQ scores. Maternal depressive symptoms during pregnancy had the strongest indirect effect. Conclusion: Maternal depressive symptoms during pregnancy mediate the association between low maternal education and child's psychosocial problems. Early recognition and treatment of maternal depressive symptoms is important to prevent psychosocial problems in children, especially in those with low education.

The Influence of Meteorological Factors and Atmospheric Pollutants on the Risk of Preterm Birth.

Atmospheric pollutants and meteorological conditions are suspected to be causes of preterm birth. We aimed to characterize their possible association with the risk of preterm birth (defined as birth occurring before 37 completed gestational weeks). We pooled individual data from 13 birth cohorts in 11 European countries (71,493 births from the period 1994-2011, European Study of Cohorts for Air Pollution Effects (ESCAPE)). City-specific meteorological data from routine monitors were averaged over time windows spanning from 1 week to the whole pregnancy. Atmospheric pollution measurements (nitrogen oxides and particulate matter) were combined with data from permanent monitors and land-use data into seasonally adjusted land-use regression models. Preterm birth risks associated with air pollution and meteorological factors were estimated using adjusted discrete-time Cox models. The frequency of preterm birth was 5.0%. Preterm birth risk tended to increase with first-trimester average atmospheric pressure (odds ratio per 5-mbar increase = 1.06, 95% confidence interval: 1.01, 1.11), which could not be distinguished from altitude. There was also some evidence of an increase in preterm birth risk with first-trimester average temperature in the -5°C to 15°C range, with a plateau afterwards (spline coding, P = 0.08). No evidence of adverse association with atmospheric pollutants was observed. Our study lends support for an increase in preterm birth risk with atmospheric pressure.