The cross-sectional association of parental psychosocial status with children's Body Mass Index z-score and the mediating role of children's energy balance behaviors - the ABCD Study

OBJECTIVE

Investigate the cross-sectional association between the psychosocial status of mothers and fathers and the BMI z-scores of their 10 to 12-year-old children. Explore whether this association is mediated by children's diet, physical activity, screen time and sleep. Analyze the moderating effect of the educational levels of both the mother and father on the association.

DESIGN

In a cross-sectional study design, children's height and weight were measured following a standardized protocol. Parents completed the validated Depression Anxiety and Stress questionnaire, while diet quality, sports participation, time spent in bed and screen time were assessed through child-report using previously validated questions.

PARTICIPANTS

The data for this study were obtained from the Amsterdam Born Children and their Development study, involving children aged 10 to 12 years and both of their parents (N = 1315).

RESULTS

The majority, 80%, of the parents were highly educated and born in the Netherlands, and 68% of the children had a healthy BMI. Maternal or paternal psychosocial status was not significantly associated with children's BMI z-score (maternal β -0.0037; 95% CI: -0.008 to 0.0007, paternal β 0.0028; 95% CI: -0.007 to 0.002). Screen time mediated the association between paternal psychosocial status and children's BMI z-score (β = 0.010, 95% CI: 0.002; 0.020). Children's diet, physical activity, and sleep did not mediate the association between paternal psychosocial status and children's BMI z-score. Parental educational level was not a moderator.

CONCLUSIONS

This research is unique in including four energy balance behaviors and including both mothers and fathers' psychosocial status. Children withfathers experiencing poorer psychosocial status engaged in more screen time which partly explained their higher BMI z-score.

Population trajectories and age-dependent associations of obesity risk factors with body mass index from childhood to adolescence across European regions: A two-cohort study

OBJECTIVE

To investigate population trajectories of behavioural risk factors of obesity from childhood to adolescence and their associations with body mass index (BMI) in children across European regions.

METHODS

Data were harmonised between the European multi-centre IDEFICS/I.Family and the Amsterdam Born Children and their Development Cohort. Participants were aged 2.0-9.9 and 5.0-7.5 years at baseline, respectively, and were followed until age 18 years. Behavioural risk factors of interest included diet, physical activity, media use and sleep. Mixed effects models were used for statistical analyses to account for repeated measurements taken from the same child.

RESULTS

The study included a total of 14 328 individuals: 4114, 4582, 3220 and 2412 participants from Northern, Southern, Eastern Europe and Amsterdam, respectively. Risk factor means and prevalences changed with age, but the trajectories were mostly similar across regions. Almost no associations between behavioural factors and BMI were found at the age of 6 years. At 11 years, daily sugar-sweetened foods consumption, use of active transport, sports club membership and longer nocturnal sleep duration were negatively associated with BMI in most regions; positive associations were found with media use. Most associations at 11 years of age persisted to 15 years.

CONCLUSIONS

Whilst population trajectories of media use and nocturnal sleep duration are similar across European regions, those of other behavioural risk factors like active transport and daily vegetable consumption differ. Also, associations between behavioural risk factors and BMI become stronger with age and show similar patterns across regions.

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.

Age-Specific Quantification of Overweight/Obesity Risk Factors From Infancy to Adolescence and Differences by Educational Level of Parents

Objectives: To explore the age-dependent associations between 26 risk factors and BMI in early life, and differences by parental educational level. Methods: Data of 10,310 children (24,155 measurements) aged 2-16 years participating in a multi-centre European cohort from 2007 to 2014 were utilized. Trajectories of overweight/obesity risk factors and their age-specific associations with BMI were estimated using polynomial mixed-effects models. Results: Exposure to most unfavourable factors was higher in the low/medium compared to the high education group, e.g., for PC/TV time (12.6 vs. 10.6 h/week). Trajectories of various risk factors markedly changed at an age of 9-11 years. Having a family history of obesity, maternal BMI, pregnancy weight gain and birth weight were positively associated with BMI trajectories throughout childhood/adolescence in both education groups; associations of behavioural factors with BMI were small. Parental unemployment and migrant background were positively associated with BMI in the low/medium education group. Conclusion: Associations of risk factors with BMI trajectories did not essentially differ by parental education except for social vulnerabilities. The age period of 9-11 years may be a sensitive period for adopting unfavourable behaviours.

The effects of hypothetical behavioral interventions on the 13-year incidence of overweight/obesity in children and adolescents

BACKGROUND

In view of the high burden of childhood overweight/obesity (OW/OB), it is important to identify targets for interventions that may have the greatest effects on preventing OW/OB in early life. Using methods of causal inference, we studied the effects of sustained behavioral interventions on the long-term risk of developing OW/OB based on a large European cohort.

METHODS

Our sample comprised 10 877 children aged 2 to < 10 years at baseline who participated in the well-phenotyped IDEFICS/I.Family cohort. Children were followed from 2007/08 to 2020/21. Applying the parametric g-formula, the 13-year risk of developing OW/OB was estimated under various sustained hypothetical interventions on physical activity, screen time, dietary intake and sleep duration. Interventions imposing adherence to recommendations (e.g. maximum 2 h/day screen time) as well as interventions 'shifting' the behavior by a specified amount (e.g. decreasing screen time by 30 min/day) were compared to 'no intervention' (i.e. maintaining the usual or so-called natural behavior). Separately, the effectiveness of these interventions in vulnerable groups was assessed.

RESULTS

The 13-year risk of developing OW/OB was 30.7% under no intervention and 25.4% when multiple interventions were imposed jointly. Meeting screen time and moderate-to-vigorous physical activity (MVPA) recommendations were found to be most effective, reducing the incidence of OW/OB by -2.2 [-4.4;-0.7] and -2.1 [-3.7;-0.8] percentage points (risk difference [95% confidence interval]), respectively. Meeting sleep recommendations (-0.6 [-1.1;-0.3]) had a similar effect as increasing sleep duration by 30 min/day (-0.6 [-0.9;-0.3]). The most effective intervention in children of parents with low/medium educational level was being member in a sports club; for children of mothers with OW/OB, meeting screen time recommendations and membership in a sports club had the largest effects.

CONCLUSIONS

While the effects of single behavioral interventions sustained over 13 years were rather small, a joint intervention on multiple behaviors resulted in a relative reduction of the 13-year OW/OB risk by between 10 to 26%. Individually, meeting MVPA and screen time recommendations were most effective. Nevertheless, even under the joint intervention the absolute OW/OB risk remained at a high level of 25.4% suggesting that further strategies to better prevent OW/OB are required.

Carrying an unintended pregnancy to term and long-term maternal psychological distress: Findings from the Dutch prospective Amsterdam Born Children and their Development study

BACKGROUND

Given the estimated high rate of unintended pregnancies, it is important to investigate long-term effects on psychological distress in women carrying an unintended pregnancy to term. However, research into associations between unintended pregnancies carried to term and psychological distress postpartum is mixed, and especially, evidence on long-term associations is scarce.

OBJECTIVE

To examine whether carrying an unintended pregnancy to term is associated with maternal psychological distress later in life, up to 12 years postpartum.

DESIGN

This study is based on the population-based birth cohort study 'Amsterdam Born Children and their Development' study, which included pregnant people in 2003 (n = 7784) and followed them up until 12 years postpartum.

METHODS

Unintended pregnancy was measured as a multidimensional construct, based on self-reported data around 16 weeks gestation on pregnancy mistiming, unwantedness and unhappiness. Symptoms of maternal psychological distress were assessed around 3 months, 5 years and 12 years postpartum using multiple questionnaires measuring symptoms of depression, anxiety and stress. Multiple structural equation modelling models were analysed, examining the associations between dimensions of unintended pregnancy and maternal psychological distress per time point, while controlling for important co-occurring risks.

RESULTS

Pregnancy mistiming and unhappiness were significant predictors of more maternal psychological distress around 3 months postpartum. Around 5 years postpartum, only pregnancy mistiming was positively associated with maternal psychological distress. Dimensions of unintended pregnancy were no longer associated with maternal psychological distress around 12 years postpartum. Strikingly, antenatal psychological distress was a much stronger predictor of maternal psychological distress than pregnancy intention dimensions.

CONCLUSION

Those who carried a more unintended pregnancy to term reported more symptoms of psychological distress at 3 months and 5 years postpartum. People carrying an unintended pregnancy to term may benefit from extra support, not because of the pregnancy intentions per se, but because they may be related to antenatal psychological distress.

Genetic association study of childhood aggression across raters, instruments, and age

Childhood aggressive behavior (AGG) has a substantial heritability of around 50%. Here we present a genome-wide association meta-analysis (GWAMA) of childhood AGG, in which all phenotype measures across childhood ages from multiple assessors were included. We analyzed phenotype assessments for a total of 328 935 observations from 87 485 children aged between 1.5 and 18 years, while accounting for sample overlap. We also meta-analyzed within subsets of the data, i.e., within rater, instrument and age. SNP-heritability for the overall meta-analysis (AGGoverall) was 3.31% (SE = 0.0038). We found no genome-wide significant SNPs for AGGoverall. The gene-based analysis returned three significant genes: ST3GAL3 (P = 1.6E-06), PCDH7 (P = 2.0E-06), and IPO13 (P = 2.5E-06). All three genes have previously been associated with educational traits. Polygenic scores based on our GWAMA significantly predicted aggression in a holdout sample of children (variance explained = 0.44%) and in retrospectively assessed childhood aggression (variance explained = 0.20%). Genetic correlations (rg) among rater-specific assessment of AGG ranged from rg = 0.46 between self- and teacher-assessment to rg = 0.81 between mother- and teacher-assessment. We obtained moderate-to-strong rgs with selected phenotypes from multiple domains, but hardly with any of the classical biomarkers thought to be associated with AGG. Significant genetic correlations were observed with most psychiatric and psychological traits (range [Formula: see text]: 0.19-1.00), except for obsessive-compulsive disorder. Aggression had a negative genetic correlation (rg = ~-0.5) with cognitive traits and age at first birth. Aggression was strongly genetically correlated with smoking phenotypes (range [Formula: see text]: 0.46-0.60). The genetic correlations between aggression and psychiatric disorders were weaker for teacher-reported AGG than for mother- and self-reported AGG. The current GWAMA of childhood aggression provides a powerful tool to interrogate the rater-specific genetic etiology of AGG.

Effect of Maternal Prepregnancy/Early-Pregnancy Body Mass Index and Pregnancy Smoking and Alcohol on Congenital Heart Diseases: A Parental Negative Control Study

Background Congenital heart diseases (CHDs) are the most common congenital anomaly. The causes of CHDs are largely unknown. Higher prenatal body mass index (BMI), smoking, and alcohol consumption are associated with increased risk of CHDs. Whether these are causal is unclear. Methods and Results Seven European birth cohorts, including 232 390 offspring (2469 CHD cases [1.1%]), were included. We applied negative exposure paternal control analyses to explore the intrauterine effects of maternal BMI, smoking, and alcohol consumption during pregnancy, on offspring CHDs and CHD severity. We used logistic regression, adjusting for confounders and the other parent's exposure and combined estimates using a fixed-effects meta-analysis. In adjusted analyses, maternal overweight (odds ratio [OR], 1.15 [95% CI, 1.01-1.31]) and obesity (OR, 1.12 [95% CI, 0.93-1.36]), compared with normal weight, were associated with higher odds of CHD, but there was no clear evidence of a linear increase in odds across the whole BMI distribution. Associations of paternal overweight, obesity, and mean BMI were similar to the maternal associations. Maternal pregnancy smoking was associated with higher odds of CHD (OR, 1.11 [95% CI, 0.97-1.25]) but paternal smoking was not (OR, 0.96 [95% CI, 0.85-1.07]). The positive association with maternal smoking appeared to be driven by nonsevere CHD cases (OR, 1.22 [95% CI, 1.04-1.44]). Associations with maternal moderate/heavy pregnancy alcohol consumption were imprecisely estimated (OR, 1.16 [95% CI, 0.52-2.58]) and similar to those for paternal consumption. Conclusions We found evidence of an intrauterine effect for maternal smoking on offspring CHDs, but no evidence for higher maternal BMI or alcohol consumption. Our findings provide further support for the importance of smoking cessation during pregnancy.

Maternal Total Cortisol Levels in Early Pregnancy Depends on Fetal Sexual Dimorphism. But Finally No Association With Birth Weight

Enhanced maternal cortisol levels may have a negative impact on fetal development with a higher risk for diseases later in life, e.g. premature cardiovascular disease and type 2 diabetes. Prior studies do assume even a sex specific impact. Currently, it is unknown whether sexual dimorphism in the fetus could display a different maternal cortisol level that is associated with intra uterine growth. In the present study (performed in the Amsterdam Born Children and their Development (ABCD) –cohort), we evaluated in 3049 pregnant women (in early pregnancy) whether fetal sex is related to the level of maternal serum total cortisol and whether this contributes to fetal growth. Maternal serum total cortisol levels increased along early pregnancy from on average 390±22 nmol/L (at 5th week of pregnancy) to 589±15 nmol/L (at 20th week of pregnancy). The presence of a female fetus was associated with higher maternal total cortisol level in a distinctive time interval along early pregnancy; before 11th week of pregnancy, no difference, and from the 12th week of pregnancy a difference of 15 (SE:7) nmol/L between mothers carrying a male vs female fetus was found and that difference increased to 45 (22) nmol/L at 20th week of pregnancy (p-for-interaction=0.05). Maternal serum total cortisol levels were negatively associated with maternal age, pBMI, smoking and parity, the last one also increasing with pregnancy duration. After adjusting for these factors, the association between fetal sex and maternal cortisol remained Maternal serum total cortisol levels were significantly associated with birth weight, standardized for pregnancy duration (ß -.22; SE:0.06; P < 0.001). Girls had a significantly lower birth weight (-132 SE:16 gram) compared to males, however, maternal cortisol did not alter the association between fetal sex and birth weight to a relevant degree indicating no mediation by maternal cortisol. In early pregnancy, the maternal total cortisol levels are related to fetal sex. However this difference in maternal total cortisol level was finally not related to birth weight.

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.

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.

Association between estimated whole-brain radiofrequency electromagnetic fields dose and cognitive function in preadolescents and adolescents

OBJECTIVE

To investigate the association between estimated whole-brain radiofrequency electromagnetic fields (RF-EMF) dose, using an improved integrated RF-EMF exposure model, and cognitive function in preadolescents and adolescents.

METHODS

Cross-sectional analysis in preadolescents aged 9-11 years and adolescents aged 17-18 years from the Dutch Amsterdam Born Children and their Development Study (n = 1664 preadolescents) and the Spanish INfancia y Medio Ambiente Project (n = 1288 preadolescents and n = 261 adolescents), two population-based birth cohort studies. Overall whole-brain RF-EMF doses (mJ/kg/day) were estimated for several RF-EMF sources together including mobile and Digital Enhanced Cordless Telecommunications phone calls (named phone calls), other mobile phone uses than calling, tablet use, laptop use (named screen activities), and far-field sources. We also estimated whole-brain RF-EMF doses in these three groups separately (i.e. phone calls, screen activities, and far-field) that lead to different patterns of RF-EMF exposure. We assessed non-verbal intelligence in the Dutch and Spanish preadolescents, information processing speed, attentional function, and cognitive flexibility in the Spanish preadolescents, and working memory and semantic fluency in the Spanish preadolescents and adolescents using validated neurocognitive tests.

RESULTS

Estimated overall whole-brain RF-EMF dose was 90.1 mJ/kg/day (interquartile range (IQR) 42.7; 164.0) in the Dutch and Spanish preadolescents and 105.1 mJ/kg/day (IQR 51.0; 295.7) in the Spanish adolescents. Higher overall estimated whole-brain RF-EMF doses from all RF-EMF sources together and from phone calls were associated with lower non-verbal intelligence score in the Dutch and Spanish preadolescents (-0.10 points, 95% CI -0.19; -0.02 per 100 mJ/kg/day increase in each exposure). However, none of the whole-brain RF-EMF doses was related to any other cognitive function outcome in the Spanish preadolescents or adolescents.

CONCLUSIONS

Our results suggest that higher brain exposure to RF-EMF is related to lower non-verbal intelligence but not to other cognitive function outcomes. Given the cross-sectional nature of the study, the small effect sizes, and the unknown biological mechanisms, we cannot discard that our resultsare due to chance finding or reverse causality. Longitudinal studies on RF-EMF brain exposure and cognitive function are needed.

The effect of maternal pre-/early-pregnancy BMI and pregnancy smoking and alcohol on congenital heart diseases: a parental negative control study

BACKGROUND

Congenital heart diseases (CHDs) are the most common congenital anomaly. The causes of CHDs are largely unknown. Higher prenatal body mass index (BMI), smoking and alcohol consumption are associated with increased risk of CHDs. Whether these are causal is unclear.

METHODS AND RESULTS

Seven European birth cohorts including 232,390 offspring (2,469 CHD cases [1.1%]) were included. We applied negative exposure paternal control analyses to explore the intrauterine effects of maternal BMI, smoking and alcohol consumption during pregnancy, on offspring CHDs and CHD severity. We used logistic regression and combined estimates using a fixed-effects meta-analysis. Analyses of BMI categories resulted in similar increased odds of CHD in overweight (mothers OR: 1.15 (1.01, 1.31) and fathers 1.10 (0.96, 1.27)) and obesity (mothers OR: 1.12 (0.93, 1.36) and fathers 1.16 (0.90, 1.50)). The association of mean BMI with CHD was null. Maternal smoking was associated with increased odds of CHD (OR: 1.11 (0.97, 1.25)) but paternal smoking was not (OR: 0.96 (0.85, 1.07)). The difference increased when removing offspring with genetic/chromosomal defects (mothers OR: 1.15 (1.01, 1.32) and fathers 0.93 (0.83, 1.05)). The positive association with maternal pregnancy smoking appeared to be driven by non-severe CHD cases (OR: 1.22 (1.04, 1.44)). Associations with maternal (OR: 1.16 (0.52, 2.58)) and paternal (OR: 1.23 (0.74, 2.06)) moderate/heavy pregnancy alcohol consumption were similar.

CONCLUSIONS

We found evidence of an intrauterine effect for maternal smoking on offspring CHDs, but no evidence for higher maternal BMI or alcohol consumption. Our findings provide further support for why smoking cessation is important during pregnancy.

A System Dynamics and Participatory Action Research Approach to Promote Healthy Living and a Healthy Weight among 10-14-Year-Old Adolescents in Amsterdam: The LIKE Programme

This paper describes the design of the LIKE programme, which aims to tackle the complex problem of childhood overweight and obesity in 10–14-year-old adolescents using a systems dynamics and participatory approach. The LIKE programme focuses on the transition period from 10-years-old to teenager and was implemented in collaboration with the Amsterdam Healthy Weight Programme (AHWP) in Amsterdam-East, the Netherlands. The aim is to develop, implement and evaluate an integrated action programme at the levels of family, school, neighbourhood, health care and city. Following the principles of Participatory Action Research (PAR), we worked with our population and societal stakeholders as co-creators. Applying a system lens, we first obtained a dynamic picture of the pre-existing systems that shape adolescents’ behaviour relating to diet, physical activity, sleep and screen use. The subsequent action programme development was dynamic and adaptive, including quick actions focusing on system elements (quick evaluating, adapting and possibly catalysing further action) and more long-term actions focusing on system goals and/or paradigm change. The programme is supported by a developmental systems evaluation and the Intervention Level Framework, supplemented with routinely collected data on weight status and health behaviour change over a period of five years. In the coming years, we will report how this approach has worked to provide a robust understanding of the programme’s effectiveness within a complex dynamic system. In the meantime, we hope our study design serves as a source of inspiration for other public health intervention studies in complex systems.

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.

Shedding Some Light in the Dark-A Comparison of Personal Measurements with Satellite-Based Estimates of Exposure to Light at Night among Children in the Netherlands

BACKGROUND

Exposure to light at night (LAN) can perturb the biological clock and affect sleep and health. Previous epidemiological studies have evaluated LAN levels measured by satellites, but the validity of this measure as a proxy for personal LAN exposure is unclear. In addition, outdoor satellite-measured LAN levels are higher in urban environments, which means that this measure could potentially represent a proxy for other, likely urban, environmental exposures.

OBJECTIVES

We evaluated correlations of satellite-assessed LAN with measured bedroom light levels and explored correlations with other environmental exposures, in particular, air pollution, green space, and area-level socioeconomic position (SEP).

METHODS

We compared satellite measurements with evening and nighttime bedroom measurements of illuminance (in units of lux) for 256 children, and we evaluated correlations between satellite-based measures and other urban exposures such as air pollution, area-level SEP, and surrounding green space for 3,021 children.

RESULTS

Satellite-measured LAN levels (nanowatts per centimeter squared per steradian) were not correlated with measured evening or nighttime lux levels [Spearman correlation coefficients ([Formula: see text]) [Formula: see text] to 0.04]. There was a weak correlation with measurements during the darkest time period if parents and their children reported that outdoor light sometimes or usually influenced indoor light levels ([Formula: see text], [Formula: see text]). In contrast, satellite-measured LAN levels were correlated with air pollution ([Formula: see text] with [Formula: see text], [Formula: see text] with [Formula: see text]), and surrounding green space ([Formula: see text] for green space within [Formula: see text] of the home). A weak correlation with area-level SEP was also observed ([Formula: see text]).

CONCLUSIONS

Outdoor satellite-assessed outdoor LAN exposure levels were correlated with urban environmental exposures, but they were not a good proxy for indoor evening or nighttime personal exposure as measured in our study population of 12-y-old children. Studies planning to evaluate potential risks from LAN should consider such modifying factors as curtains and indoor lighting and the use of electronic devices and should include performing indoor or personal measurements to validate any exposure proxies. The moderate-to-strong correlation of outdoor LAN with other environmental exposures should be accounted for in epidemiological investigations. https://doi.org/10.1289/EHP3431.

Prospective associations of age at complementary feeding and exclusive breastfeeding duration with body mass index at 5-6 years within different risk groups

BACKGROUND

Children with overweight or obesity are at risk for developing obesity in adulthood. Certain maternal characteristics, such as ethnicity, education, body mass index (BMI) or neighbourhood, are determinants for childhood overweight risk. There are large variations in how mothers differing in these characteristics feed their infants. Therefore, associations of age at complementary feeding, exclusive breast feeding duration with childhood overweight may differ in these groups. Understanding these associations would be essential to develop overweight prevention strategies.

OBJECTIVES

The objective of this study is to study the associations of age at complementary feeding, exclusive breastfeeding duration with BMI-standard deviation score (SDS) at 5-6 years within risk groups.

METHODS

Using data from the Amsterdam Born Children and their Development study, a population-based birth cohort (n = 4495), we formed groups of children at varying risk of overweight according to maternal characteristics of ethnicity, education, pre-pregnancy BMI and neighbourhood. Linear and logistic regression analyses were conducted.

RESULTS

Complementary feeding after 5 months of age was associated with lower BMI-SDS in children of mothers of Dutch ethnicity (B: -0.12; 95% CI: -0.21, -0.04), medium-level education (-0.19; -0.30, -0.08), normal BMI (-0.08; -0.16, -0.01) and high-risk neighbourhood (-0.16; -0.29, -0.02). Compared with exclusive breastfeeding for <3 months, exclusive breastfeeding for ≥6 months was associated with lower BMI-SDS in groups of medium-level education (-0.28; 0.44, -0.11), normal BMI (-0.18; -0.29, -0.08) and medium-risk (-0.18; -0.33, -0.04) and high-risk (-0.22; -0.42, -0.02) neighbourhoods.

CONCLUSIONS

Associations between infant feeding practices and childhood BMI may differ between risk groups, implying that overweight prevention strategies should be group-specific.

Maternal cell phone use during pregnancy and child behavioral problems in five birth cohorts

INTRODUCTION

Previous studies have reported associations between prenatal cell phone use and child behavioral problems, but findings have been inconsistent and based on retrospective assessment of cell phone use. This study aimed to assess this association in a multi-national analysis, using data from three cohorts with prospective data on prenatal cell phone use, together with previously published data from two cohorts with retrospectively collected cell phone use data.

METHODS

We used individual participant data from 83,884 mother-child pairs in the five cohorts from Denmark (1996-2002), Korea (2006-2011), the Netherlands (2003-2004), Norway (2004-2008), and Spain (2003-2008). We categorized cell phone use into none, low, medium, and high, based on frequency of calls during pregnancy reported by the mothers. Child behavioral problems (reported by mothers using the Strengths and Difficulties Questionnaire or Child Behavior Checklist) were classified in the borderline/clinical and clinical ranges using validated cut-offs in children aged 5-7years. Cohort specific risk estimates were meta-analyzed.

RESULTS

Overall, 38.8% of mothers, mostly from the Danish cohort, reported no cell phone use during pregnancy and these mothers were less likely to have a child with overall behavioral, hyperactivity/inattention or emotional problems. Evidence for a trend of increasing risk of child behavioral problems through the maternal cell phone use categories was observed for hyperactivity/inattention problems (OR for problems in the clinical range: 1.11, 95%CI 1.01, 1.22; 1.28, 95%CI 1.12, 1.48, among children of medium and high users, respectively). This association was fairly consistent across cohorts and between cohorts with retrospectively and prospectively collected cell phone use data.

CONCLUSIONS

Maternal cell phone use during pregnancy may be associated with an increased risk for behavioral problems, particularly hyperactivity/inattention problems, in the offspring. The interpretation of these results is unclear as uncontrolled confounding may influence both maternal cell phone use and child behavioral problems.

Occupational Exposure to Endocrine-Disrupting Chemicals and Birth Weight and Length of Gestation: A European Meta-Analysis

BACKGROUND

Women of reproductive age can be exposed to endocrine-disrupting chemicals (EDCs) at work, and exposure to EDCs in pregnancy may affect fetal growth.

OBJECTIVES

We assessed whether maternal occupational exposure to EDCs during pregnancy as classified by application of a job exposure matrix was associated with birth weight, term low birth weight (LBW), length of gestation, and preterm delivery.

METHODS

Using individual participant data from 133,957 mother-child pairs in 13 European cohorts spanning births from 1994 through 2011, we linked maternal job titles with exposure to 10 EDC groups as assessed through a job exposure matrix. For each group, we combined the two levels of exposure categories (possible and probable) and compared birth outcomes with the unexposed group (exposure unlikely). We performed meta-analyses of cohort-specific estimates.

RESULTS

Eleven percent of pregnant women were classified as exposed to EDCs at work during pregnancy, based on job title. Classification of exposure to one or more EDC group was associated with an increased risk of term LBW [odds ratio (OR) = 1.25; 95% CI: 1.04, 1.49], as were most specific EDC groups; this association was consistent across cohorts. Further, the risk increased with increasing number of EDC groups (OR = 2.11; 95% CI: 1.10, 4.06 for exposure to four or more EDC groups). There were few associations (p < 0.05) with the other outcomes; women holding job titles classified as exposed to bisphenol A or brominated flame retardants were at higher risk for longer length of gestation.

CONCLUSION

Results from our large population-based birth cohort design indicate that employment during pregnancy in occupations classified as possibly or probably exposed to EDCs was associated with an increased risk of term LBW. Citation: Birks L, Casas M, Garcia AM, Alexander J, Barros H, Bergström A, Bonde JP, Burdorf A, Costet N, Danileviciute A, Eggesbø M, Fernández MF, González-Galarzo MC, Gražulevičienė R, Hanke W, Jaddoe V, Kogevinas M, Kull I, Lertxundi A, Melaki V, Andersen AM, Olea N, Polanska K, Rusconi F, Santa-Marina L, Santos AC, Vrijkotte T, Zugna D, Nieuwenhuijsen M, Cordier S, Vrijheid M. 2016. Occupational exposure to endocrine-disrupting chemicals and birth weight and length of gestation: a European meta-analysis. Environ Health Perspect 124:1785-1793; http://dx.doi.org/10.1289/EHP208.

Perinatal outcome in singleton pregnancies complicated with preeclampsia and eclampsia in Ecuador

Preeclampsia in Ecuador is an understudied subject since available epidemiological data are scarce. The aim of this study was to describe perinatal outcomes among singleton pregnancies complicated with preeclampsia and eclampsia in a sample of low-income Ecuadorian women. Pregnant women complicated with preeclampsia (mild and severe) and eclampsia (defined according to criteria of the ACOG) delivering at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital, Guayaquil, Ecuador were surveyed with a structured questionnaire containing maternal (socio-demographic) and neonatal data. Perinatal outcomes were compared according to severity of clinical presentation. A total of 163 women with preeclampsia [mild (23.9%), severe (68.7%) and eclampsia (7.4%)] were surveyed. Perinatal mortality and stillbirth rate was similar among studied groups (mild vs. severe preeclampsia/eclampsia cases). However, severe cases displayed higher rates of adverse perinatal outcomes: lower birth Apgar scores, more preterm births, and more low birth weight and small for gestational age infants. Caesarean-section rate and the number of admissions to intensive or intermediate neonatal care were higher in severe cases. A similar trend was found when analysis excluded preterm gestations. In conclusion, in this specific low-income Ecuadorian population perinatal outcome was adverse in pregnancies complicated with severe preeclampsia/eclampsia.

[Ethnic differences in uptake of professional maternity care assistance]

OBJECTIVE

To examine the ethnic differences in the uptake of professional maternity care assistance (MCA) in the Netherlands, and the factors that may explain these differences. Additionally the effect of MCA on health risk behaviour around infants is examined.

DESIGN

Questionnaire survey.

METHOD

Questionnaire data from 3967 mothers from the ABCD study (Amsterdam Born Children and their Development) included during pregnancy in 2003-2004, were used. We examined the explanatory role of ethnicity, age, socioeconomic status, mastery of the Dutch language, parity, housing situation and place of giving birth on MCA uptake, and the effect of MCA uptake on health risk behaviour around infants, such as smoking indoors, infant sleep behaviour, infant nutrition, and response to infant crying.

RESULTS

Mothers of non-Western origin less often used MCA than Dutch mothers (Ghanaian: 70%; Turkish: 75%; Moroccan: 79%; Surinamese: 81%; Dutch Caribbean: 85% vs. Dutch: 95%). Higher educational level, better mastery of the Dutch language, having a paid job and home delivery were all independently associated with the uptake of MCA, and also partially explained ethnic differences in the uptake of MCA. Mothers who received MCA more often breastfed, more often gave vitamin K when not breastfeeding, and more often lived in smoke-free homes. The protective effect of MCA was stronger for non-Western mothers than for Dutch mothers.

CONCLUSION

Mothers of non-Western origin make less use of professional MCA. Given that the use of MCA is associated with a less risk behaviour around infants, efforts should be made to improve the accessibility of professional MCA for mothers of non-Western origin.

Antenatal maternal anxiety is associated with problem behaviour at age five

BACKGROUND

Developmental programming by maternal stress during pregnancy is found to influence behavioural development in the offspring.

AIM

To prospectively investigate the association between antenatal maternal anxiety and children's behaviour rated by their mothers and teachers.

METHODS

In a large, community based birth-cohort (the ABCD-study) antenatal maternal state-anxiety (M = 36.7, SD = 9.8) was measured around the 16th week of gestation. Five years later, 3,446 mothers and 3,520 teachers evaluated 3,758 children's overall problem behaviour, emotional symptoms, conduct problems, hyperactivity/inattention problems, peer relationship problems and pro-social behaviour.

RESULTS

Hierarchical multiple regression analysis using a large number of potential covariates revealed that children of mothers who reported higher levels of anxiety during their pregnancy showed more overall problem behaviour, hyperactivity/inattention problems, emotional symptoms, peer relationship problems, conduct problems and showed less pro-social behaviour when mothers rated their child's behaviour. When teachers rated child behaviour, children showed more overall problem behaviour and less pro-social behaviour that was related to antenatal anxiety. The child's sex moderated the association between antenatal anxiety with overall problem behaviour and hyperactivity/inattention problems when reported by the mother. In boys, exposure to antenatal anxiety was associated with a stronger increase in overall problem behaviour compared to girls. Furthermore, antenatal anxiety was significantly related to an increase in hyperactivity/inattention problems in boys, while this was not the case in girls.

CONCLUSIONS

Exposure to antenatal maternal anxiety is associated with children's problem behaviour, with different outcome patterns for both sexes. Nevertheless, effect sizes in this study were small.

The validity and reliability of the Dutch Effort-Reward Imbalance Questionnaire

The reliability and validity of the Effort-Reward Imbalance Questionnaire were tested in 775 blue- and white-collar workers in the Netherlands. Cronbach's alpha revealed sufficient internal consistency of all subscales except Need for Control. With exploratory probabilistic scaling (Mokken) analysis, the psychometric qualities of the Need for Control scale were improved. With confirmatory factor analysis, the factorial validity of the Extrinsic Effort and Reward subscales was confirmed. A model with 3 separate dimensions for reward (status control, esteem reward, and monetary gratification) proved adequate, emphasizing the importance of distinguishing subscales. The congruent validity of the subscales and a hypothesized relationship with an external construct, health functioning, were confirmed.

The validity and reliability of the Dutch Effort-Reward Imbalance Questionnaire

The reliability and validity of the Effort-Reward Imbalance Questionnaire were tested in 775 blue- and white-collar workers in the Netherlands. Cronbach's alpha revealed sufficient internal consistency of all subscales except Need for Control. With exploratory probabilistic scaling (Mokken) analysis, the psychometric qualities of the Need for Control scale were improved. With confirmatory factor analysis, the factorial validity of the Extrinsic Effort and Reward subscales was confirmed. A model with 3 separate dimensions for reward (status control, esteem reward, and monetary gratification) proved adequate, emphasizing the importance of distinguishing subscales. The congruent validity of the subscales and a hypothesized relationship with an external construct, health functioning, were confirmed.