Eva M. Loomans

Maternal hypothyroxinemia in early pregnancy predicts reduced performance in reaction time tests in 5- to 6-year-old offspring.

CONTEXT Overt hypothyroidism in pregnant women is associated with poorer neurodevelopment in their children. Findings from studies investigating the effect of less severe impairments in the maternal thyroid function on cognitive functioning in offspring are difficult to interpret for a number of reasons, including lack of objective cognitive tests, preschool age at assessment, and small sample sizes. OBJECTIVE We aimed to assess the effect of the maternal thyroid status in early pregnancy on their offsprings cognitive performance at 5 to 6 years of age. DESIGN AND PARTICIPANTS This was a prospective study that included the data of 1765 healthy 5- to 6-year-old children from the Amsterdam Born Children and their Development study. Maternal serum free T4 and TSH were obtained at a median gestational age of 90 (interquartile range, 83 to 100) days. MAIN OUTCOME MEASURES Cognitive performance was tested using a computerized assessment program that measured response speed, response speed stability, visuomotor skills, response selection, and response inhibition. RESULTS Maternal hypothyroxinemia (ie, maternal free T4 in the lowest 10% of distribution) was associated with a 41.3 (95% confidence interval, 20.3-62.4) ms slower response speed in a simple reaction time task. In this test, it was also associated with a decreased stability in response speed. The relations found persisted after adjustment for family background and perinatal conditions. The effect of hypothyroxinemia on these outcomes was dependent on its interaction with TSH level. CONCLUSIONS Lower maternal free T4 concentration at the end of the first trimester predicted slower response speed and decreased stability in response speed in offspring at 5 to 6 years of age.

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 childrens 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 childrens 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 childs behaviour. When teachers rated child behaviour, children showed more overall problem behaviour and less pro-social behaviour that was related to antenatal anxiety. The childs 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 childrens problem behaviour, with different outcome patterns for both sexes. Nevertheless, effect sizes in this study were small.

Caffeine Intake During Pregnancy and Risk of Problem Behavior in 5- to 6-Year-Old Children

BACKGROUND AND OBJECTIVE: Human studies that have investigated the association between caffeine intake during pregnancy and offspring’s behavioral outcomes are scant and inconclusive. We prospectively investigated the association between maternal caffeine intake during pregnancy and children’s problem behavior at age 5 to 6 years. Mediation by fetal growth restriction and gestational age as well as effect modification by the child’s gender and maternal smoking was tested. METHODS: In a community based multiethnic birth cohort, dietary caffeine intake (coffee, caffeinated tea, and cola) was measured (maternal self-report, n = 8202) around the 16th week of gestation. At age 5, children’s overall problem behavior, emotional problems, conduct problems, hyperactivity/inattention problems, peer relationship problems, and prosocial behavior were rated by both mother and teacher (n = 3439) with the Strengths and Difficulties Questionnaire. Analyses were adjusted for maternal age, ethnicity, cohabitant status, education, smoking and alcohol consumption during pregnancy, child’s gender, family size, and prenatal maternal anxiety. RESULTS: Caffeine intake was not associated with a higher risk for behavior problems or with suboptimal prosocial behavior. No evidence was found for mediation by fetal growth restriction or gestational age, nor for effect modification by the child’s gender. CONCLUSIONS: Results did not provide evidence for developmental programming influences of intrauterine exposure to caffeine on offspring’s problem behavior at age 5. Present results give no indication to advise pregnant women to reduce their caffeine intake to prevent behavior problems in their children.

Modelling indoor electromagnetic fields (EMF) from mobile phone base stations for epidemiological studies.

Radio frequency electromagnetic fields (RF-EMF) from mobile phone base stations can be reliably modelled for outdoor locations, using 3D radio wave propagation models that consider antenna characteristics and building geometry. For exposure assessment in epidemiological studies, however, it is especially important to determine indoor exposure levels as people spend most of their time indoors. We assessed the accuracy of indoor RF-EMF model predictions, and whether information on building characteristics could increase model accuracy. We performed 15-minute spot measurements in 263 rooms in 101 primary schools and 30 private homes in Amsterdam, the Netherlands. At each measurement location, we collected information on building characteristics that can affect indoor exposure to RF-EMF, namely glazing and wall and window frame materials. Next, we modelled RF-EMF at the measurement locations with the 3D radio wave propagation model NISMap. We compared model predictions with measured values to evaluate model performance, and explored if building characteristics modified the association between modelled and measured RF-EMF using a mixed effect model. We found a Spearman correlation of 0.73 between modelled and measured total downlink RF-EMF from base stations. The average modelled and measured RF-EMF were 0.053 and 0.041mW/m(2), respectively, and the precision (standard deviation of the differences between predicted and measured values) was 0.184mW/m(2). Incorporating information on building characteristics did not improve model predictions. Although there is exposure misclassification, we conclude that it is feasible to reliably rank indoor RF-EMF from mobile phone base stations for epidemiological studies.

Maternal cell phone and cordless phone use during pregnancy and behaviour problems in 5-year-old children

Background A previous study found an association between maternal cell phone use during pregnancy and maternal-reported child behaviour problems at age 7. Together with cell phones, cordless phones represent the main exposure source of radiofrequency-electromagnetic fields to the head. Therefore, we assessed the association between maternal cell phone and cordless phone use during pregnancy and teacher-reported and maternal-reported child behaviour problems at age 5. Methods The study was embedded in the Amsterdam Born Children and their Development study, a population-based birth cohort study in Amsterdam, the Netherlands (2003–2004). Teachers and mothers reported child behaviour problems using the Strength and Difficulties Questionnaire at age 5. Maternal cell phone and cordless phone use during pregnancy was asked when children were 7 years old. Results A total of 2618 children were included. As compared to non-users, those exposed to prenatal cell phone use showed an increased but non-significant association of having teacher-reported overall behaviour problems, although without dose-response relationship with the number of calls (OR=2.12 (95% CI 0.95 to 4.74) for <1 call/day, OR=1.58 (95% CI 0.69 to 3.60) for 1–4 calls/day and OR=2.04 (95% CI 0.86 to 4.80) for ≥5 calls/day). ORs for having teacher-reported overall behaviour problems across categories of cordless phone use were below 1 or close to unity. Associations of maternal cell phone and cordless phone use with maternal-reported overall behaviour problems remained non-significant. Non-significant associations were found for the specific behaviour problem subscales. Conclusion Our results do not suggest that maternal cell phone or cordless phone use during pregnancy increases the odds of behaviour problems in their children.

Maternal Long-Chain Polyunsaturated Fatty Acid Status during Early Pregnancy and Children's Risk of Problem Behavior at Age 5-6 Years

OBJECTIVE To prospectively investigate the association between maternal long-chain polyunsaturated fatty acid (LCPUFA) status and ratio during pregnancy and childrens risk of problem behavior at 5 years of age. STUDY DESIGN Maternal LCPUFA status in plasma phospholipids during pregnancy (M = 13.3, SD = 3 weeks) was available for 4336 women. Childrens behavior was rated by their mother (n = 2502) and teacher (n = 2061). RESULTS When using multivariate logistic regression analyses, we found that greater concentrations of omega-3 fatty acid docosahexaenoic acid (OR 0.75; 95% CI 0.56-0.99; P = .05) decreased childrens risk for emotional symptoms. Although lower eicosapentaenoic acid and a greater omega-6:omega-3 LCPUFA (ie, arachidonic acid/[docosahexaenoic acid + eicosapentaenoic acid]) tended to increase the risk for emotional symptoms and the risk of hyperactivity/inattention problems for the omega-6:omega-3 LCPUFA, the results were nonsignificant (P = .07). No evidence was found for mediation by preterm birth and being small for gestational age. The childs sex and infant feeding pattern did not modify the associations. CONCLUSION Our results suggest long-term developmental programming influences of maternal LCPUFA status during pregnancy and stress the importance of an adequate and balanced supply of fatty acids in pregnant women for optimal fetal brain development and subsequent long-term behavioral outcomes.

Early life influences on cognition, behavior, and emotion in humans: from birth to age 20

The long-lasting effects of fetal exposure to early life influences (ELI) such as maternal anxiety, stress, and micronutrient deficiencies as well as mediating and moderating factors are quite well established in animal studies, but remain unclear in humans. Here, we report about effects on cognition, behavior, and emotion in offspring aged 5-20 years old in two prospective longitudinal birth cohorts.