Little evidence that time in child care causes externalizing problems during early childhood in Norway

Early childcare arrangements and children's internalizing and externalizing symptoms: an individual participant data meta-analysis of six prospective birth cohorts in Europe

Background

Early childcare attendance may be related to children's internalizing and externalizing symptoms throughout childhood and young adolescence, however evidence from Europe is limited. We aimed to assess this association across multiple population-based birth cohorts of children recruited in different European countries.

Methods

Data come from six parent-offspring prospective birth cohort studies across five European countries within the EU Child Cohort Network. A total of 87,208 parent-child dyads were included in the study. To test associations between childcare attendance (centre-based or informal) anytime between ages 0 and 4 years and children's internalizing and externalizing symptoms in middle childhood and young adolescence (measured at: 5-6 years, 7-9 years, and 10-13 years) a two-stage individual participant data meta-analysis was implemented. Linear regression models were performed in each cohort separately; combined random-effects meta-analysis was then used to obtain overall association estimates. In secondary analyses, we tested interactions between childcare attendance and mother's post-partum depression, low education status, and the child's sex.

Findings

Compared to children who were exclusively cared for by their parents prior to school entry, those who attended centre-based childcare had lower levels of internalizing symptoms in all age groups [5-6 years: β: -1.78 (95% CI: -3.39, -0.16); 7-9 years: β: -0.55 (95% CI: -0.88, -0.73); 10-13 years: β: -0.76 (95% CI: -1.15, -0.37)]. Children who attended informal childcare appeared to have elevated levels of internalizing symptoms between 7-9 and 10-13 years, respectively [β: 1.65 (95% CI: 1.25, 2.06); β: 1.25 (95% CI: 0.96, 1.54)]. Informal childcare attendance was also associated with increased levels of children's externalizing symptoms between 7-9 and 10-13 years, respectively [β: 2.84 (95% CI: 1.41, 4.26); β: 2.19 (95% CI: 0.54, 3.84)].

Interpretation

Early centre-based childcare is associated with decreased levels of children's internalizing symptoms compared to exclusive parental care. For informal childcare, opposite associations were observed. Overall, our results suggest that centre-based childcare attendance may be associated with slight positive impacts on children's emotional development and should be encouraged by public policies. In addition, children from socioeconomically disadvantaged families require special attention, as they may not sufficiently benefit from universal early childhood education and care (ECEC).

Funding

This research was funded by the ERC Consolidator grant RESEDA (Horizon Europe, 101001420).

Non-parental Childcare During Early Childhood and Problem Behaviour Trajectories from Ages 5 to 14 Years

Using data from the nationally representative Millennium Cohort Study, this study examined the association between age of starting and weekly hours in formal childcare between birth and 5 years with internalising and externalising behaviour trajectories from ages 5 to 14 years in England (N = 6194 children). Associations were analysed using multilevel general linear regression models, with adjustment for socio-economic position, maternal mental health, demographics, and child temperament. Later entry was associated with more internalising behaviours at age 14 years. Children who spent > 40 h per week in childcare between birth and 3 years displayed more externalising behaviour at 5 years than children who did not attend childcare. Controlling for socio-economic position and parental mental health attenuated findings.

Revisiting the childcare-attachment question: under what conditions is childcare participation associated with mother-child attachment security?

Decades have passed since the controversy regarding the putative risks of childcare for mother-child attachment broke out. Yet, some uncertainty remains, as relevant studies have produced inconsistent evidence. Some have proposed that those conflicting findings may be due to the fact that the effects of childcare are conditioned on parenting. Accordingly, this study examined whether relations between childcare participation and mother-child attachment vary according to maternal sensitivity and autonomy support. In this sample of 236 mother-child dyads, there was no indication of main effects of childcare participation on attachment. There were, however, some interactive effects, such that the children who showed the least secure attachment behaviors were those who did not attend childcare and had either less sensitive or less autonomy-supportive mothers. The findings suggest that the effects of childcare on mother-child attachment are best understood in light of the parenting children receive at home.

The double jeopardy of low family income and negative emotionality: The family stress model revisited

The family stress model has, for decades, guided empirical work linking poverty with increased risk of child social-emotional dysfunction. The present study extends this line of work by examining whether child negative emotionality moderates associations between family income, family stress (maternal distress, parental locus of control, and relationship dissatisfaction), and later externalizing and internalizing behavior problems. In a longitudinal population-based sample (n ~ 80,000) of Norwegian children followed from birth through age five (The Norwegian Mother, Father, and Child Cohort Study; MoBa), we examined whether high (vs. moderate or low) negative emotionality families would display: (a) compounding stress (i.e., particularly strong associations between low family income and family stress), (b) diathesis-stress (i.e., particularly strong associations between family stress and behavior problems), or (c) double jeopardy (i.e., both compounding stress and diathesis-stress moderating effects). Negative emotionality significantly moderated the association between family income and behavior problems in a manner most consistent with double jeopardy. As a result, compared with children with moderate/low negative emotionality, the family income-behavior problems association was two to three times larger for those with higher negative emotionality. These findings underscore the active role children may play in family processes that link low family income with behavior problems.

Association between the starting age of non-parental Early Childhood Education and Care (ECEC), and psycho-social problems in adolescence in West and East Germany - a natural experiment using data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS)

INTRODUCTION

The study aimed to investigate the association between the start age of non-parental Early Childhood Education and Care (ECEC) and psycho-social problems in adolescence. The similarities and differences between West and East Germany were also investigated in a natural experiment.

METHODS

Our sample consisted of 1022 children (621 from West Germany, 401 from East Germany) aged 3-4 years at wave 2003-2006 that were followed up to wave 2014-2017 as adolescents (mean ± SD age = 14.4 ± 0.03 years) in the KiGGS study. The psycho-social problems were measured by the parent-reported Strengths and Difficulties Questionnaire (SDQ) at wave 2014-2017. Linear regression was used to explore the relationship between ECEC-start-age and psycho-social problems in adolescence in Germany, and stratified by West and East Germany.

RESULTS

Those who started ECEC between 2 and 3 years old (reference) had the lowest scores of psycho-social problems in the whole Germany and in West Germany in adolescence. In comparison, those who started ECEC older than 3 years old had higher scores of internalizing psycho-social problems in both West Germany (with statistically significant results) and East Germany (with a relatively larger effect size but insignificant results). Those who started ECEC younger than 1 year old had statistically significant higher scores for externalizing psycho-social problems in West Germany, even though less children started ECEC younger than 1 in West Germany compared to East Germany. This significant association was not found in East Germany. Those who started ECEC between 1 and 2 years old tended to have higher scores of externalizing psycho-social problems in both West and East Germany.

CONCLUSION

The results suggest that if children start ECEC older than 3 years or younger than 2 years, more attention needs to be given to internalizing or externalizing psycho-social problems respectively. The regional differences for children younger than 1 year old may suggest a selection effect in West Germany where only fewer parents bring babies to ECEC, while the regional similarities for children over 3 years old indicate the importance of providing access to ECEC for children over 3 years old.

Positive maternal mental health attenuates the associations between prenatal stress and children's internalizing and externalizing symptoms

Positive maternal mental health can improve perceptions of stressful situations and promote the use of adaptive coping strategies. However, few studies have examined how positive maternal mental health affects children's development. The aims of this study were to examine the associations between positive maternal mental health and children's internalizing and externalizing symptoms, and to ascertain whether positive maternal mental health moderated the associations between prenatal stress and children's internalizing and externalizing symptoms. This study is based on the Norwegian Mother, Father, and Child Cohort Study (MoBa), and comprised 36,584 mother-child dyads. Prenatal stress was assessed using 41 self-reported items measured during pregnancy. Positive maternal mental health (self-efficacy, self-esteem, and enjoyment) was assessed by maternal report during pregnancy and postpartum. Child internalizing and externalizing symptoms were assessed by maternal report at age 5. Structural equation modeling was used for analysis. Maternal self-efficacy, self-esteem, and enjoyment were negatively associated with internalizing and externalizing symptoms in males and females. The association between prenatal stress and internalizing symptoms in males was stronger at low than at high levels of maternal self-esteem and enjoyment, whereas for females, the association was stronger at low than at high levels of maternal self-esteem and self-efficacy. This study provides evidence of associations between positive maternal mental health and children's mental health, and suggests that higher positive maternal mental health may buffer against the impacts of prenatal stress. Positive maternal mental health may represent an important intervention target to improve maternal-child well-being and foster intergenerational resilience.

Early care and education

This chapter briefly reviews the history of early care and education (ECE) in the United States, the ECE conceptual frameworks, how ECE is organized, who uses ECE, and associations between ECE experiences and child outcomes. Nonparent care is now experienced by most children in the United States, with home-based care most common for infants and toddlers and center-based care for preschoolers. ECE settings that involve frequent and responsive teacher-child interactions and access to age-appropriate activities appear to promote children's cognitive and social development, although those associations tend to be quite modest. Publicly funded programs like Head Start and pre-kindergarten programs tend to serve children from low-income families, and are successful in promoting school readiness skills, especially early academic skills. However, the impacts of today's programs largely disappear in the first years of elementary school, and even flipped from being positive to negative in the methodologically most rigorous studies. Explanations for this fadeout are explored.

Do more hours in center-based care cause more externalizing problems? A cross-national replication study

Whether high quantities of center-based care cause behavior problems is a controversial question. Studies using covariate adjustment for selection factors have detected relations between center care and behavior problems, but studies with stronger internal validity less often find such evidence. We examined whether within-child changes in hours in center-based care predicted changes in externalizing problems in toddlers and preschoolers (N = 10,105; 49% female; data collection 1993-2012) in seven studies, including from Germany, Netherlands, Norway, two from Canada and two from the U.S. Race/ethnicity data were only collected in the United States (57% and 80% White; 42% and 13% African-American; 1.2% and 5% Latinx). Meta-analyses showed no association (r = .00, p = .88) between hours in center-based care and externalizing problems.

Prenatal mercury exposure, fish intake and child emotional behavioural regulation in the Norwegian Mother, Father and Child Cohort Study

Objective

While maternal fish consumption in pregnancy has consistently been linked to better cognitive and emotional outcomes in children, fish is also a primary source of exposure to methyl mercury (MeHg), which has been linked to poorer child cognitive outcomes. The aim of this study was to evaluate the associations between MeHg exposure, using calculated MeHg exposure from maternal diet and total mercury (Hg) concentration in maternal blood during pregnancy, and child internalising and externalising behaviours at 3 and 5 years of age.

Design and participants

The study sample comprised 51 238 mother-child pairs in the Norwegian Mother, Father and Child Cohort Study. Data on maternal blood Hg concentration in gestational week 18 were available for a sub-sample of 2936 women. Maternal MeHg exposure from diet was calculated from a validated Food Frequency Questionnaire answered in mid-pregnancy. Mothers reported children's emotional behaviour at age 3 and 5 years by questionnaires including twenty items from the Child Behaviour Checklist. Longitudinal associations were examined using generalised estimating equations, adjusted for potential confounders and stratified by maternal fish intake.

Results

Maternal blood Hg concentration (median=1.02 µg/L, 90th percentile=2.22, range=0-13.8) was not associated with emotional behaviour in children. Increasing dietary MeHg intake (median 0.15 µg/kg body weight/week, 90th percentiles=0.31, range=0-1.86) was significantly associated with lower internalising β=-0.03 (95% CI -0.05 to -0.00) and externalising child behaviours β=-0.04 (95% CI -0.07 to -0.02) in adjusted models. The inverse associations were also apparent when stratifying by low/high maternal fish intake (<400 and ≥400 g/week).

Conclusions

The results indicated that prenatal MeHg exposure, well below the weekly tolerable intake established by European Food Safety Authority (1.3 µg/kg bw), did not adversely affect child emotional regulation. Children of mothers consuming fish regularly were less likely to show signs of emotional behavioural problems.

Maternal and paternal anxiety during pregnancy: Comparing the effects on behavioral problems in offspring

Prenatal maternal anxiety has been associated with both short and long-term mental health problems in the child. The current study aims to examine the association between maternal and paternal prenatal anxiety and behaviour problems in the child at 1.5 and 5 years, using three different approaches; (1) adjusting for covariates, (2) using fathers' anxiety during pregnancy as a negative control, and (3) using a sibling-comparison design, controlling for unmeasured family factors. We used data from the Norwegian Mother, Father and Child Cohort Study (MoBa) is used. MoBa is a cohort consisting of about 114 000 pregnancies (about 34000 siblings) recruited from 1999 to 2008. Self-reported measures on maternal anxiety were obtained twice in pregnancy and 6 months after birth, while paternal anxiety was reported prenatally at 17th weeks of gestation. Maternal reports on child behaviour problems were obtained at 1.5 and 5 years of age. Results suggests that prenatal exposure to maternal anxiety was associated with behaviour problems at 1.5 years: adjusted beta (β) = 0.13 (CI = 0.12, 0.15), and at 5 years: β = 0.11 (CI = 0.09, 0.14). However, paternal anxiety was also associated with behaviour problems at 1.5 years: β = 0.03 (CI = 0.01-0.03) and at 5 years β = 0.03 (CI = 0.02, 0.03). These associations were attenuated in the sibling comparison analyses: β = -0.02 (CI = -0.02-0.05) at 1.5 years and β = -0.05 (CI = -0.10, 0.02) at 5 years. In conclusions, the sibling analyses are not consistent with a direct effect of prenatal maternal anxiety on child behaviour problems. It is more likely that genetic or shared family environment explain this association.

External childcare and socio-behavioral development in Switzerland: Long-term relations from childhood into young adulthood

This study examined early external childcare in relation to development from age 7 to 20. A Swiss sample was used (N = 1,225; 52% male). Development included multi-informant-reported externalizing behavior, internalizing problems, prosocial behavior, delinquency, and substance use. Growth curve models revealed that, dependent on the informant, time in a daycare center was related to increased externalizing and internalizing problems until at least age 11. It was not related to delinquency. Roughly three days per week at a daycare mother or playgroup was related to increased externalizing behavior. External family care was associated with increased prosocial behavior. Finally, time in a daycare center was associated with fewer externalizing but more internalizing problems and substance use for children from vulnerable backgrounds. This relation with substance use lasted to age 20.

Association between colic and sleep problems in infancy and subsequent development, emotional and behavioral problems: a longitudinal study

Background

Sleep and colic problems in infancy have been linked to adverse health outcome, but there is limited knowledge of the association between sleep and colic problems in infancy and subsequent development, emotional and behavior problems in young children. The aim of the present study was to examine whether there is an associations between infants’ crying and sleep problems at 6 months and behavioral and development problems at 18 months, 3 and 5 years.

Methods

This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa), conducted at the Norwegian Institute of Public Health from June 1999 to December 2008. A total of 86,724 children were included. Colic and sleep (sleep duration, nocturnal awakenings and easy to put to bed) was assessed by mother-reports. Z-scores were used to assess differences between groups of children (e.g. having colic or not, having a sleep problem or not). Emotional and behavioral problems were measured with items from the Child Behavior Checklist. Development problems were measured with items from The Ages and Stages Questionnaire.

Results

Infants with colic scored significantly lower on development at 5 years (B=-0.10, CI [− 0.14 to - 0.06]) and higher on internalizing problems both at 3 years (B=0.15. CI [0.11 to 0.18]) and 5 years (B=0.17. CI [0.12 to 0.21]) than the reference population. Children who awoke frequently and were more difficult to put to bed at 6 months scored significantly lower on development at 18 months and 3 and 5 years, and higher on internalizing behavior problems at 3 and 5 years (B=0.18 and B=0.16). Children with shorter sleep duration at 6 months had more internalizing behavior problems at 3 years (B=0.14. CI [0.07 to 0.21]) and 5 years (B=0.15. CI [0.05 to 0.25]) than the reference population.

Conclusions

Colic and sleep problems early in life should be taken into account as risk factors for development and behavioral problems within the first 5 years of a child’s life.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-020-02483-1.

Early environmental risk factors for neurodevelopmental disorders - a systematic review of twin and sibling studies

While neurodevelopmental disorders (NDDs) are highly heritable, several environmental risk factors have also been suggested. However, the role of familial confounding is unclear. To shed more light on this, we reviewed the evidence from twin and sibling studies. A systematic review was performed on case control and cohort studies including a twin or sibling within-pair comparison of neurodevelopmental outcomes, with environmental exposures until the sixth birthday. From 7,315 screened abstracts, 140 eligible articles were identified. After adjustment for familial confounding advanced paternal age, low birth weight, birth defects, and perinatal hypoxia and respiratory stress were associated with autism spectrum disorder (ASD), and low birth weight, gestational age and family income were associated with attention-deficit/hyperactivity disorder (ADHD), categorically and dimensionally. Several previously suspected factors, including pregnancy-related factors, were deemed due to familial confounding. Most studies were conducted in North America and Scandinavia, pointing to a global research bias. Moreover, most studies focused on ASD and ADHD. This genetically informed review showed evidence for a range of environmental factors of potential casual significance in NDDs, but also points to a critical need of more genetically informed studies of good quality in the quest of the environmental causes of NDDs.

Peer-Victimization of Young Children With Developmental and Behavioral Difficulties-A Population-Based Study

OBJECTIVE

The aim is to investigate if young children with developmental and behavioral difficulties (DBDs) have greater risk of peer-victimization compared with typically developing (TD) children.

METHOD

The sample was drawn from the Norwegian Mother and Child Cohort Study (MoBa). MoBa has collected population-based data on children's health and development for 114,500 children. We included children that were 5 years of age (n = 41,609). Multivariate logistic regression was used to estimate the effect of different DBDs and of co-occurring DBDs on peer-victimization compared with TD children. Categories of DBDs included autistic traits, emotional difficulties, behavioral difficulties, general learning difficulties, attention difficulties/impulsive behavior, motor development difficulties, language difficulties, and hearing and vision difficulties. Results were adjusted for socioeconomic status and the child's sex.

RESULTS

Peer-victimization was 2.8% (933) among TD children, and 8.0% (615) among children with DBD. The highest risk of peer-victimization was found among children with autistic traits and children with five or more co-occurring DBDs (adjusted odds ratios [ORs] = 12.76; 95% confidence interval [CI] 8.64-18.84; p ≤ .001) and 17.37 (95% CI 12.15-24.82; p ≤ .001)], respectively. The lowest risk was found among children with hearing and vision difficulties and children with only one DBD [adjusted ORs = 1.98 (95% CI 1.71-2.29; p ≤ .001) and 1.95 (95% CI 1.70-2.22; p ≤ .001)].

CONCLUSION

Children with DBD have a substantially higher risk of peer-victimization compared with TD children. Peer-victimization varies with type of DBD and increases cumulatively by number of DBDs.

Pathways to behavior problems in Norwegian kindergarten children: The role of parent emotion socialization and child emotion understanding

More than two decades of research have shown that parental emotion-related socialization behaviors (ERSBs) significantly predict child emotion understanding and externalizing behavior problems. This study aimed to replicate these findings in a sample of 40 Norwegian preschool children and to test whether the effect of parental ERSBs on externalizing child behavior problems was mediated through child emotion understanding. Parental report on ERSBs was obtained using the Coping with Children's Negative Emotions Scale (CCNES) questionnaire. Child emotion understanding was assessed directly using the Test of Emotion Comprehension (TEC). The results showed that parental distress reactions and externalizing child behavior problems were significantly correlated and that parental expressive encouragement was significantly correlated with child emotion understanding. Estimation of indirect effects was conducted using process analysis and showed that parental expressive encouragement was indirectly related to externalizing child behavior problems (b = -0.17) via child emotion understanding. The results suggest that better child emotion understanding, and lower parental distress are related to lower levels of behavior problems in preschool children. These findings provide support for the Parental Meta-Emotion Philosophy (PMEP) model, where the effect of parental emotion socialization on externalizing child behavior problems is mediated through emotion understanding.

Maternal Drinking and Child Emotional and Behavior Problems

BACKGROUND AND OBJECTIVES

Maternal drinking is associated with child emotional and behavior problems. There is, however, a lack of studies that properly account for confounding. Our objective was to estimate the association between at-risk drinking in mothers of young children and child emotional and behavior problems, taking into account the passive transmission of familial risk.

METHODS

This population-based sample consists of 34 039 children nested within 21 911 nuclear families and 18 158 extended families from the Norwegian Mother, Father, and Child Cohort Study. Participants were recruited between 1999 and 2009 during routine ultrasound examinations. Data were collected during the 17th and 30th gestational week and when the children were 1.5, 3, and 5 years old. We applied a multilevel structural equation model that accounted for unobserved familial risks.

RESULTS

Children of mothers with at-risk drinking had a higher likelihood of behavior problems (β = 3.53; 95% confidence interval [CI] 3.01 to 4.05) than children of mothers with low alcohol consumption. This association was reduced after adjusting for factors in the extended family (β = 1.93; 95% CI 1.16 to 2.71) and the nuclear family (β = 1.20; 95% CI 0.39 to 2.01). Maternal at-risk drinking had a smaller association with child emotional problems (β = 1.80; 95% CI 1.26 to 2.34). This association was reduced after adjusting for factors in the extended family (β = 0.67; 95% CI -0.12 to 1.46) and the nuclear family (β = 0.58; 95% CI -0.31 to 1.48).

CONCLUSIONS

The results suggest an association between maternal at-risk drinking and child behavior problems. A reduction in maternal drinking may improve outcomes for children with such symptoms.

Early childhood child care and disruptive behavior problems during adolescence: a 17-year population-based propensity score study

BACKGROUND

Child-care services during early childhood provide opportunities for social interactions that may facilitate children's learning of acceptable social behaviors. Furthermore, they may reduce exposure to family adversity for some children. The aim of this study was to determine whether intensity of exposure to child-care services prior to age 5 years has a beneficial effect on disruptive behavior problems during adolescence, and whether the effect is more pronounced for children from low socioeconomic families.

METHODS

N = 1,588 participants from the Québec Longitudinal Study of Child Development were assessed 14 times from 5 months to 17 years. Intensity of child-care exposure was measured from 5 months to 5 years of age. Main outcomes were self-reported physical aggression and opposition from age 12 to 17 years. Family socioeconomic status (SES) was measured at 5 months. Factors explaining differences in child-care use were controlled using propensity score weights (PSW).

RESULTS

Children exposed to moderate-intensity child-care services (part-time child-care services before 1½ years and full time afterward) reported lower levels of physical aggression (d = -.11, p = .056) and opposition (d = -.14, p = .029) during adolescence compared to children exposed to low-intensity child-care services. A significant child care by SES interaction (p = .017) for physical aggression indicated that the moderate-intensity child-care effect was specific to children from low SES families (d = -.36, p = .002). No interaction with socioeconomic status was found for opposition.

CONCLUSIONS

Moderate-intensity child-care services from infancy to school entry may prevent disruptive behavior during adolescence, especially for disadvantaged children.

How Lifestyle Factors Affect Cognitive and Executive Function and the Ability to Learn in Children

In today's research environment, children's diet, physical activity, and other lifestyle factors are commonly studied in the context of health, independent of their effect on cognition and learning. Moreover, there is little overlap between the two literatures, although it is reasonable to expect that the lifestyle factors explored in the health-focused research are intertwined with cognition and learning processes. This thematic review provides an overview of knowledge connecting the selected lifestyle factors of diet, physical activity, and sleep hygiene to children's cognition and learning. Research from studies of diet and nutrition, physical activity and fitness, sleep, and broader influences of cultural and socioeconomic factors related to health and learning, were summarized to offer examples of research that integrate lifestyle factors and cognition with learning. The literature review demonstrates that the associations and causal relationships between these factors are vastly understudied. As a result, current knowledge on predictors of optimal cognition and learning is incomplete, and likely lacks understanding of many critical facts and relationships, their interactions, and the nature of their relationships, such as there being mediating or confounding factors that could provide important knowledge to increase the efficacy of learning-focused interventions. This review provides information focused on studies in children. Although basic research in cells or animal studies are available and indicate a number of possible physiological pathways, inclusion of those data would distract from the fact that there is a significant gap in knowledge on lifestyle factors and optimal learning in children. In a climate where childcare and school feeding policies are continuously discussed, this thematic review aims to provide an impulse for discussion and a call for more holistic approaches to support child development.

Impact of prenatal exposure to benzodiazepines and z-hypnotics on behavioral problems at 5 years of age: A study from the Norwegian Mother and Child Cohort Study

Many women experience anxiety or sleep disorders during pregnancy and require pharmacological treatment with benzodiazepines (BZDs) or z-hypnotics. Limited information is currently available on how prenatal exposure to these medications affects behavioral problems in children over the long term. Therefore, from a public health perspective, this issue is highly important. The present study aimed to determine whether prenatal exposure to BZDs and z-hypnotics affected externalizing and internalizing behavior problems in children at age 5 years. This study was based on The Norwegian Mother and Child Cohort Study and The Medical Birth Registry of Norway. The final study population included data for 36 401 children, from questionnaires completed by the mothers throughout the 5-year follow up. Children’s behaviors were measured at age 5, based on parental responses to The Child Behavior Checklist. Children T-scores of 63 or above were considered to indicate clinically relevant behavior problems. We applied inverse probability of treatment weighting (IPTW) and log-binomial regression models to estimate risk ratios (RRs) and bootstrapped 95% confidence intervals (CIs) with censoring weights to account for loss during follow-up. Several sensitivity analyses were performed to assess the robustness of the main results. The final sample included 273 (0.75%) children that were exposed to BZDs and/or z-hypnotics during pregnancy. The main, IPTW and censoring weighted analyses showed that prenatal exposure to BZD and/or z-hypnotics increased the risks of internalizing behavioral problems (RR: 1.35, 95% CI: 0.73–2.49) and externalizing behavioral problems (RR: 1.51, 95% CI: 0.86–2.64). However, based on sensitivity analyses, we concluded that the risks of displaying externalizing and internalizing problems at 5 years of age did not significantly increase after prenatal exposure to BZDs and/or z-hypnotics. Instead, the sensitivity analyses suggested that residual confounding and selection bias might explain the increased risks observed in the main analyses.

Is the association between maternal alcohol consumption in pregnancy and pre-school child behavioural and emotional problems causal? Multiple approaches for controlling unmeasured confounding

BACKGROUND AND AIMS

Hazardous drinking (i.e. alcohol consumption that places drinkers at risk for adverse health outcomes) during pregnancy is associated with adverse child outcomes. To address whether the associations are causal, we aimed to estimate the effect of maternal hazardous drinking during the first trimester on offspring emotional and behavioural problems throughout the pre-school age. We adjusted for: (1) measured confounding (e.g. smoking), (2) familial risk factors by sibling control design and (3) non-shared environmental risk factors by using hazardous drinking the 3 months before pregnancy as an instrumental variable.

DESIGN

Prospective cohort study. Participants were recruited between 1999 and 2009 at ultrasound examination offered to all pregnant women in Norway. Data were collected during the 17th and the 30th weeks of gestation, and when the children were aged 1.5, 3 and 5 years.

SETTING

Norway, 1999-2015.

PARTICIPANTS

The sample consisted of 14 639 mothers with 25 744 offspring siblings from the Norwegian Mother and Child Cohort Study.

MEASUREMENTS

Respondents self-reported on: alcohol consumption, children's emotional problems (i.e. emotional reactive, anxiety/depression, somatic complaints) and children's behavioural problems (i.e. attention and aggressive behaviour) throughout pre-school age. We used longitudinal latent growth curve models to estimate the effect of maternal drinking during the first trimester on offspring emotional and behavioural problems.

FINDINGS

Most associations were strongly reduced after controlling for both familial and measured environmental risk factors. After adjustment, exposed children were more emotionally reactive [β = 2.33; 95% confidence interval (CI) = 0.13-4.53] and had more somatic complaints (β = 1.93; 95% CI = 0.09-3.77) at age 3, but not at age 5. Exposed children were less aggressive than unexposed siblings at age 5 (β = -2.27; 95% CI = -4.02 to -0.52).

CONCLUSIONS

Children exposed to their mothers' hazardous drinking during the first trimester appear to be more emotionally reactive and have more somatic complaints at age 3, but not at age 5, and are less aggressive at age 5 compared with unexposed siblings.

THE PERSISTENCE OF PRESCHOOL EFFECTS FROM EARLY CHILDHOOD THROUGH ADOLESCENCE

Using data from the Early Childhood Longitudinal Study Kindergarten Cohort of 1998 (n = 15,070), this study used propensity scores to examine the short- and long-term academic and psychosocial benefits of preschool education for a diverse sample of middle-class children. Compared with children who attended informal care at age 4, preschool attendees consistently performed better on achievement tests from age 5 through early adolescence, but exhibited less optimal psychosocial skills. These negative behavioral effects of preschool were concentrated among children who attended preschool for 20 or more hours per week, but otherwise, there was little evidence of heterogeneity as a function of program type or child- and family-characteristics. The long-term academic advantages of preschool were, however, largely explained by their positive effects on academic skills early in formal schooling and there was evidence for convergence in children's academic test scores, which was partially attributed to the differences in children's social skills during the early elementary school years.

Re-examining the link between prenatal maternal anxiety and child emotional difficulties, using a sibling design

Background

Prenatal exposure to maternal anxiety has been associated with child emotional difficulties in a number of epidemiological studies. One key concern, however, is that this link is vulnerable to confounding by pleiotropic genes or environmental family factors.

Methods

Data on 82 383 mothers and children from the population-based Mother and Child Cohort Study and data on 21 980 siblings were used in this study. Mothers filled out questionnaires for each unique pregnancy, for infant difficulties at 6 months and for emotional difficulties at 36 months. The link between prenatal maternal anxiety and child difficulties were examined using logistic regression analyses and multiple linear regression analyses for the full study sample and the sibling sample.

Results

In the conventional full-cohort analyses, prenatal exposure to maternal anxiety was associated with child difficulties at both 6 months [odds ratio (OR) = 2.1 (1.94-2.27)] and 36 months [OR = 2.72 (2.47-2.99)]. The findings were essentially the same whether we examined difficulties at 6 months or at 36 months. However, these associations were no longer present once we controlled for potential social and genetic confounders in the sibling comparison analyses, either at 6 months [OR = 1.32 (0.91-1.90)] or at 36 months [OR = 1.28 (0.63-2.60)]. Findings from multiple regression analyses with continuous measures were essentially the same.

Conclusions

Our finding lends little support for there being an independent prenatal effect on child emotional difficulties; rather, our findings suggest that the link between prenatal maternal anxiety and child difficulties could be confounded by pleiotropic genes or environmental family factors.

Developmental Origins of Chronic Physical Aggression: A Bio-Psycho-Social Model for the Next Generation of Preventive Interventions

This review describes a bio-psycho-social approach to understanding and preventing the development of chronic physical aggression. The debate on the developmental origins of aggression has historically opposed genetic and environmental mechanisms. Recent studies have shown that the frequency of physical aggression peaks in early childhood and then decreases until old age. Molecular genetic studies and twin studies have confirmed important genetic influences. However, recent epigenetic studies have highlighted the important role of environments in gene expression and brain development. These studies suggest that interrelated bio-psycho-social channels involved in the development of chronic physical aggression are generally the product of an intergenerational transmission process occurring through assortative mating, genetic inheritance, and the inheritance of physical and social environmental conditions that handicap brain functioning and support the use of physical aggression to solve problems. Given these intergenerational mechanisms and physical aggression onset in infancy, it appears clear that preventive interventions should start early in pregnancy, at the latest.

Peer Effects on Aggressive Behavior in Norwegian Child Care Centers

This study examined whether exposure to changes in peer aggression predicted changes in child physical aggression (PA) in preschool children attending Norwegian Early Childhood Education and Care (ECEC) centers. Data from the Behavior Outlook Norwegian Developmental Study were used, including 956 children. In fixed effects models, within-child changes in exposure to peer aggression predicted changes in teacher-rated child PA across ages 2, 3, and 4. Moreover, changes in exposure to a peer group with two or more externalizing children increased teacher-rated child PA over time, but only for boys. No significant peer effects on parent-rated child PA were found. Findings point to the importance of avoiding the congregation of several problematic children, particularly boys, in the same ECEC groups.

The influence of parental concern on the utility of autism diagnostic instruments

The parental report-based Autism Diagnostic Interview-Revised (ADI-R) and the clinician observation-based Autism Diagnostic Observation Schedule (ADOS) have been validated primarily in U.S. clinics specialized in autism spectrum disorder (ASD), in which most children are referred by their parents because of ASD concern. This study assessed diagnostic agreement of the ADOS-2 and ADI-R toddler algorithms in a more broadly based sample of 679 toddlers (age 35-47 months) from the Norwegian Mother and Child Cohort. We also examined whether parental concern about ASD influenced instrument performance, comparing toddlers identified based on parental ASD concern (n = 48) and parent-reported signs of developmental problems (screening) without a specific concern about ASD (n = 400). The ADOS cutoffs showed consistently well-balanced sensitivity and specificity. The ADI-R cutoffs demonstrated good specificity, but reduced sensitivity, missing 43% of toddlers whose parents were not specifically concerned about ASD. The ADI-R and ADOS dimensional scores agreed well with clinical diagnoses (area under the curve ≥ 0.85), contributing additively to their prediction. On the ADI-R, different cutoffs were needed according to presence or absence of parental ASD concern, in order to achieve comparable balance of sensitivity and specificity. These results highlight the importance of taking parental concern about ASD into account when interpreting scores from parental report-based instruments such as the ADI-R. While the ADOS cutoffs performed consistently well, the additive contributions of ADI-R and ADOS scores to the prediction of ASD diagnosis underscore the value of combining instruments based on parent accounts and clinician observation in evaluation of ASD. Autism Res 2017, 10: 1672-1686. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Early Nonparental Care and Social Behavior in Elementary School: Support for a Social Group Adaptation Hypothesis

This study examined the contribution of nonparental child-care services received during the preschool years to the development of social behavior between kindergarten and the end of elementary school with a birth cohort from Québec, Canada (N = 1,544). Mothers reported on the use of child-care services, while elementary school teachers rated children's shyness, social withdrawal, prosociality, opposition, and aggression. Children who received nonparental child-care services were less shy, less socially withdrawn, more oppositional, and more aggressive at school entry (age 6 years). However, these differences disappeared during elementary school as children who received exclusive parental care caught up with those who received nonparental care services. This "catch-up" effect from the perspective of children's adaptation to the social group is discussed.

Child effects and child care: Implications for risk and adjustment

Evocative effects of child characteristics on the quality and quantity of child care were assessed in two studies using longitudinal data from the NICHD Study of Early Child Care. We focus on the influence of child characteristics on two important aspects of the child care experience: language stimulation provided by caregivers and quantity of care. In Study 1, associations between the developmental status of children aged 15 to 54 months and the language stimulation provided by their caregivers were examined using path models, and longitudinal child effects were detected across the earliest time points of the study. In Study 2, the associations among child behavior, temperament, development, and time in care were examined. Little evidence was found for such child effects on time in care. The results are discussed in terms of the effects of child care on child development and implications for developmental processes, particularly for children at greatest risk for developmental delay or psychopathology.

Age of Entry Into Early Childhood Education and Care as a Predictor of Aggression

Socioemotional risks associated with nonparental care have been debated for decades, and research findings continue to be mixed. Yet few studies have been able to test the causal hypothesis that earlier, more extensive, and longer durations of nonmaternal care lead to more problems. To examine the consequences of age of entry into nonparental care for childhood aggression, we used prospective longitudinal data from Norway, where month of birth partly determines age of entry into Early Childhood Education and Care (ECEC) centers. In this sample of 939 children followed from ages 6 months through 4 years, ECEC teachers reported the children’s aggression when they were 2, 3, and 4 years old. We found some evidence that age of entry into ECEC predicted aggression at age 2, albeit modestly and not robustly. Between the ages of 2 and 4 years, the effect of age of entry on aggression faded to negligible levels. The implications for psychological science and policy are discussed.

Behavioural effects of fetal antidepressant exposure in a Norwegian cohort of discordant siblings

OBJECTIVE

Potential adverse effects of prenatal antidepressant exposure on child development are still debated. The possibility that associations are due to genetic or familial environmental risk factors rather than antidepressant use per se cannot easily be ruled out in conventional studies. Our objective was therefore to evaluate the association between prenatal antidepressant exposure and behavioural problems in a sibling controlled study.

METHOD

This study used data on 20 180 siblings identified from the population-based Norwegian Mother and Child Cohort Study recruited between 1999 and 2008. The mothers were asked to report antidepressant use at gestational weeks 17 and 30 and 6 months post-partum. Child Behavioral Checklist syndrome scales were used to assess externalizing and internalizing behavioural problems by questionnaires sent to mothers at 18 and 36 months postpartum. We performed unmatched and matched sibling analyses using both random- and fixed-effects linear models, respectively, to determine potential behavioural effects of antidepressant exposure.

RESULTS

Prenatal exposure to antidepressants was associated with increased levels of anxiety symptoms in 3 year old children after adjusting for maternal familial effects and confounding by indication (i.e. maternal depression). Effect of prenatal exposure to antidepressants was specific to anxiety, and not associated with emotional reactivity, somatic complaints, sleep problems, attention problems or aggression.

CONCLUSION

Using a sibling design, we showed that prenatal antidepressant use was specifically associated with increased anxiety symptoms after adjusting for maternal familial factors and confounding by indication.

Informal child care and adolescent psychological well-being: Hong Kong's "Children of 1997" birth cohort

BACKGROUND

Informal child care (child care by untrained family members, relatives or employees in the home) in Western populations is often associated with poorer psychological well-being, which may be confounded by socioeconomic position. We examined the association of informal child care, common in non-Western settings, with adolescent psychological well-being, using Hong Kong's Chinese "Children of 1997" birth cohort.

METHODS

Multivariable linear regression was used to examine the adjusted associations of informal child care (at 0.5, 3, 5 and 11 years) with parent-reported Rutter score for child behavior at 11 years, self-reported Culture-Free Self-Esteem Inventories score at 11 years and self-reported Patient Health Questionnaire-9 depressive symptom score at 13 years. Model comparisons were used to identify the best representation of child care, in terms of a critical period of exposure to informal child care (independent variable) at a specific age, combination of exposures to informal child care at several ages or an accumulation of exposures to informal child care.

RESULTS

Child care was not associated with behavioral problems. A model considering child care at 3 years best represented the association of child care with self-esteem while a model considering child care at 5 years best represented the association of child care with depressive symptoms. Informal child care at 3 years was associated with lower self-esteem (-0.70, 95% confidence interval (CI) -1.26 to -0.14). Informal child care at 5 years was associated with more depressive symptoms (0.45, 95% CI 0.17 to 0.73).

CONCLUSION

In a developed non-Western setting, informal child care was associated with lower self-esteem and more depressive symptoms.

Time spent in different types of childcare and children's development at school entry: an Australian longitudinal study

OBJECTIVE

To investigate whether the total amount of time in childcare through the first 3 years of life was associated with children's receptive vocabulary, externalising and internalising problem behaviours at age 4-5 years, and whether this association varied for different types of childcare.

METHODS

We used data from the prospective, population-based Longitudinal Study of Australian Children (n=3208-4066, depending on outcome). Parental reports of the time spent in different types of childcare were collected at face-to-face interviews at age 0-1years and at age 2-3 years. Children's receptive vocabulary was directly assessed in the child's home, and externalising and internalising behaviours were measured by questionnaire, completed by parents and teachers at age 4-5 years.

RESULTS

At 3 years of age, 75% of the sample spent regular time in the care of someone other than the parent. After adjustment, more time in childcare was not associated with children's receptive vocabulary ability but was associated with higher levels of parent-reported (β=0.10 (95% CI 0.00 to 0.21)) and teacher-reported (β=0.31 (0.19 to 0.44)) externalising problem behaviours and lower levels of parent-reported internalising problem behaviours (β=-0.08 (-0.15 to -0.00)). Compared with children who did not attend any type of childcare, children in centre-based care had higher parent-reported and teacher-reported externalising and lower internalising problem behaviours.

CONCLUSIONS

More time in centre-based childcare (but not other types of care) through the first 3 years of life was associated with higher parent-reported and teacher-reported externalising problem behaviours, and lower parent-reported internalising problem behaviours but not with children's receptive vocabulary ability at school entry.

Family income dynamics, early childhood education and care, and early child behavior problems in Norway

The sociopolitical context of Norway includes low poverty rates and universal access to subsidized and regulated Early Childhood Education and Care (ECEC). In this context, the association between family income dynamics and changes in early child behavior problems was investigated, as well as whether high-quality ECEC buffers children from the effects of income dynamics. In a population-based sample (N = 75,296), within-family changes in income-to-needs predicted changes in externalizing and internalizing problems (from ages 18 to 36 months), particularly for lower income children. For internalizing problems, ECEC buffered the effect of income-to-needs changes. These findings lend further support to the potential benefits of ECEC for children from lower income families.

Child care, socio-economic status and problem behavior: a study of gene-environment interaction in young Dutch twins

The influences of formal child care before age 4 on behavioral problems at 3, 5, and 7 years of age were assessed in 18,932 Dutch twins (3,878 attended formal child care). The effect of formal child care was studied on the average level of problem behavior and as moderator of genetic and non-genetic influences, while taking into account effects of sex and parental socio-economic status (SES). There was a small association between attending formal child care and higher externalizing problems, especially when SES was low. Heritability was lower for formal child care and in lower SES conditions. These effects were largest at age 7 and for externalizing problems. In 7 year-old boys and girls, the difference in heritability between the formal child care group of low SES and the home care group of high SES was 30% for externalizing and ~20% for internalizing problems. The decrease in heritability was explained by a larger influence of the environment, rather than by a decrease in genetic variance. These results support a bioecological model in which heritability is lower in circumstances associated with more problem behavior.

Prenatal paracetamol exposure and child neurodevelopment: a sibling-controlled cohort study

BACKGROUND

Paracetamol is used extensively during pregnancy, but studies regarding the potential neurodevelopmental sequelae of foetal paracetamol exposure are lacking. Method Between 1999 and 2008 all pregnant Norwegian women were eligible for recruitment into the prospective Norwegian Mother and Child Cohort Study. The mothers were asked to report on their use of paracetamol at gestational weeks 17 and 30 and at 6 months postpartum. We used data on 48 631 children whose mothers returned the 3-year follow-up questionnaire by May 2011. Within this sample were 2919 same-sex sibling pairs who were used to adjust for familial and genetic factors. We modelled psychomotor development (communication, fine and gross motor development), externalizing and internalizing behaviour problems, and temperament (emotionality, activity, sociability and shyness) based on prenatal paracetamol exposure using generalized linear regression, adjusting for a number of factors, including febrile illness, infections and co-medication use during pregnancy.

RESULTS

The sibling-control analysis revealed that children exposed to prenatal paracetamol for more than 28 days had poorer gross motor development [β 0.24, 95% confidence interval (CI) 0.12-0.51], communication (β 0.20, 95% CI 0.01-0.39), externalizing behaviour (β 0.28, 95% CI 0.15-0.42), internalizing behaviour (β 0.14, 95% CI 0.01-0.28), and higher activity levels (β 0.24, 95% CI 0.11-0.38). Children exposed prenatally to short-term use of paracetamol (1-27 days) also had poorer gross motor outcomes (β 0.10, 95% CI 0.02-0.19), but the effects were smaller than with long-term use. Ibuprofen exposure was not associated with neurodevelopmental outcomes.

CONCLUSION

Children exposed to long-term use of paracetamol during pregnancy had substantially adverse developmental outcomes at 3 years of age.

Genetic vulnerability interacts with parenting and early care education to predict increasing externalizing behavior

The current study examined interactions among genetic influences and children's early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental regulation. Early environments included both family (overreactive parenting) and out-of-home factors (center-based Early Care and Education; ECE). Overreactive parenting predicted more child externalizing behaviors. Attending center-based ECE was associated with increasing externalizing behaviors only for children with genetic liability for dysregulation. Additionally, children who were at risk for externalizing behaviors due to both genetic variability and exposure to center-based ECE were more sensitive to the effects of overreactive parenting on externalizing behavior than other children.

Maternal and early postnatal nutrition and mental health of offspring by age 5 years: a prospective cohort study

OBJECTIVE

Diet quality is related to the risk for depression and anxiety in adults and adolescents; however, the possible impact of maternal and early postnatal nutritional exposures on children's subsequent mental health is unexplored.

METHOD

The large prospective Norwegian Mother and Child Cohort Study recruited pregnant women between 1999 and 2008. Data were collected from mothers during pregnancy and when children were 6 months and 1.5, 3, and 5 years of age. Latent growth curve models were used to model linear development in children's internalizing and externalizing problems from 1.5 to 5 years of age as a function of diet quality during pregnancy and at 1.5 and 3 years. Diet quality was evaluated by dietary pattern extraction and characterized as "healthy" or "unhealthy." The sample comprised 23,020 eligible women and their children. Adjustments were made for variables including sex of the child, maternal depression, maternal and paternal age, maternal educational attainment, household income, maternal smoking before and during pregnancy, mothers' parental locus of control, and marital status.

RESULTS

Higher intakes of unhealthy foods during pregnancy predicted externalizing problems among children, independently of other potential confounding factors and childhood diet. Children with a high level of unhealthy diet postnatally had higher levels of both internalizing and externalizing problems. Moreover, children with a low level of postnatal healthy diet also had higher levels of both internalizing and externalizing problems.

CONCLUSION

Among this large cohort of mothers and children, early nutritional exposures were independently related to the risk for behavioral and emotional problems in children.