Comparison of outcomes of the 50-year follow-up of a randomized trial assessed by study questionnaire and by data linkage: The CONCUR study.

BACKGROUND/AIMS: Self-reported questionnaires on health status after randomized trials can be time-consuming, costly, and potentially unreliable. Administrative data sets may provide cost-effective, less biased information, but it is uncertain how administrative and self-reported data compare to identify chronic conditions in a New Zealand cohort. This study aimed to determine whether record linkage could replace self-reported questionnaires to identify chronic conditions that were the outcomes of interest for trial follow-up. METHODS: Participants in 50-year follow-up of a randomized trial were asked to complete a questionnaire and to consent to accessing administrative data. The proportion of participants with diabetes, pre-diabetes, hyperlipidaemia, hypertension, mental health disorders, and asthma was calculated using each data source and agreement between data sources assessed. RESULTS: Participants were aged 49 years (SD = 1, n = 424, 50% male). Agreement between questionnaire and administrative data was slight for pre-diabetes (kappa = 0.10), fair for hyperlipidaemia (kappa = 0.27), substantial for diabetes (kappa = 0.65), and moderate for other conditions (all kappa >0.42). Administrative data alone identified two to three times more cases than the questionnaire for all outcomes except hypertension and mental health disorders, where the questionnaire alone identified one to two times more cases than administrative data. Combining all sources increased case detection for all outcomes. CONCLUSIONS: A combination of questionnaire, pharmaceutical, and laboratory data with expert panel review were required to identify participants with chronic conditions of interest in this follow-up of a clinical trial.

Long-term health conditions among household families in Aotearoa New Zealand: cross-sectional analysis of integrated Census and administrative data.

AIM: Little is known about the extent to which families in Aotearoa New Zealand are affected by long-term health conditions (HCs). This study aimed to explore the rates of nine selected HCs among New Zealand family members within the same household. METHOD: Linked population and administrative health data were obtained for families living in the same household according to the 2013 New Zealand Census (N=1,043,172). Health data (2008-2013) were used to ascertain whether people in these families (N=3,137,517) received treatment or services for nine selected HCs: cancer, chronic obstructive pulmonary disease, heart disease, diabetes, dementia, gout, stroke, traumatic brain injury (TBI), or mental health/behaviour conditions (MHBCs). RESULTS: Over 60% of families included at least one person with a HC, and this rate was higher among multi-generation families (73.9%). The most common HCs were MHBCs (39.4% of families), diabetes (16.0%) and TBI (13.9%). At the highest level of socio-economic deprivation, 57.6% of children aged under 18 years lived with a family member who had a HC. CONCLUSION: Three in five New Zealand household families included someone with at least one of nine selected HCs, with differences in the proportion affected according to family composition, socio-economic status and an individual's ethnicity. This suggests that there are a substantial number of people at risk of the poor outcomes associated with the experience of HCs within their family.

Association between maternal depression symptoms and child telomere length.

The biological mechanisms that explain how adverse early life events influence adult disease risk are poorly understood. One proposed mechanism is via the induction of accelerated biological aging, for which telomere length is considered a biomarker. We aimed to determine if maternal depression pre- and post-partum was associated with telomere length in children at 4 years of age (n = 4299). Mothers completed structured questionnaires assessing depression during pregnancy (Edinburgh Depression Scale), at 9 months (Edinburgh Depression Scale), and at 54 months postpartum (Patient Health Questionnaire 9). Regression methods were used to investigate the relationship between telomere length (DNA from saliva) and maternal depression score recorded at each stage. Significant covariates included in the final model were: maternal age at pregnancy; child sex; child ethnicity; gestational age group, and rurality group. Child telomere length was found to be longer if their mother had a higher depression score at both postpartum time points tested (9 months of age; coefficient 0.003, SE = 0.001, P = 0.01, 54 months of age; coefficient 0.003, SE = 0.002, P = 0.02). Although these findings seem paradoxical, increased telomere length may be an adaptive response to early life stressors. We propose several testable hypotheses for these results and to determine if the positive association between depression and telomere length is a developmental adaptation or an indirect consequence of environmental factors.

Manifold child, family and social variables are associated with injury among New Zealand preschool children.

AIM: Approaches to understanding child injury tend to focus on short-term proximal influences. Previous analyses have found higher rates of injury among Maori and Pacific children in Aotearoa New Zealand (NZ). This study aimed to investigate how combinations of situations and multiple events act across the life-course to either protect preschool children from, or place them at risk of, repeated injuries requiring medical attention. METHODS: Longitudinal data were used to identify parent-reported injuries requiring medical attention among 6114 preschool NZ children. The environments experienced by children with multiple and/or severe injury were explored using multivariable analyses. RESULTS: Eight percent of children (n=505) experienced 1-3 injuries with at least one hospitalisation or ≥4 injuries (high injury group) from birth to 4.5 years of age. After accounting for antenatal, sociodemographic and psychosocial variables, children of Maori mothers (OR=0.7, 95% CI 0.5 to 0.97) and children of Asian mothers (OR=0.5, 95% CI 0.3 to 0.7) were less likely to be in the high injury group than children of European mothers. After adjusting for maternal ethnicity and child variables (gender, temperament, level of activity and behaviour difficulties), cumulative exposure to factors in four domains was associated with injury category: maternal, family, social and service use. CONCLUSION: This study identified social and economic opportunities to lower rates of injury among preschool children, that might reduce associated direct and indirect costs. Our findings in relation to ethnicity go against the standard public rhetoric and provide support for shifting the apportioning of blame for child injury from individuals to wider environmental exposures for which public health and societal solutions are required.

Age at first exposure to antibiotics and neurodevelopmental outcomes in childhood.

RATIONALE: Viral illnesses in children are common and are frequently treated with antibiotic medication. Antibiotics reduce the diversity and composition of the gut microbiota, leading to poor developmental outcomes. OBJECTIVES: To investigate the relationship between age at first exposure to antibiotics and cognitive and behavioural development at 4.5 years while controlling for multiple confounders, including otitis media. METHODS: Study participants were 5589 children enrolled in the broadly generalisable Growing Up in New Zealand cohort study, with antibiotic exposure data, maternal antenatal information, and age 4.5-year behaviour and cognitive outcome data. Children were categorised as first exposed to antibiotics according to the following mutually exclusive ages: 0-2 months; 3-5 months; 6-8 months; 9-11 months; 12-54 months or not exposed by 54 months. Developmental outcome measures included the Strengths and Difficulties Questionnaire, Luria hand clap task, and the Peabody Picture Vocabulary Test-III. RESULTS: In univariate analysis, there was an evident dose-response relationship where earlier exposure to antibiotics in the first year of life was associated with behavioural difficulties, lower executive function scores, and lower receptive language ability. After adjusting for confounders, pairwise comparisons showed that first antibiotic exposure between birth and 3 months or between 6 and 9 months was associated with lower receptive vocabulary. Antibiotic exposure at any age prior to 12 months was associated with increases in behavioural difficulties scores at 4.5 years. CONCLUSIONS: Following adjustment for socioeconomic factors and otitis media, there is evidence that antibiotic exposure during potentially sensitive windows of development is associated with receptive language and behaviour later in childhood.

Epilepsy severity mediates association between mutation type and ADHD symptoms in tuberous sclerosis complex.

The association between attention-deficit/hyperactivity disorder (ADHD) and tuberous sclerosis complex (TSC) is widely reported, with support for the role of epilepsy, yet the mechanisms underlying the association across development are unclear. The Tuberous Sclerosis 2000 Study is a prospective longitudinal study of TSC. In Phase 1 of the study, baseline measures of epilepsy, cortical tuber load, and mutation were obtained with 125 children ages 0-16 years. In Phase 2, at an average of 8 years later, ADHD symptoms were measured for 81 of the participants. Structural equation modeling revealed an indirect pathway from genetic mutation, to cortical tuber load, to epileptic spasm severity in infancy, to ADHD symptoms in middle childhood and adolescence, in addition to a pathway linking current seizure severity to ADHD symptoms. Findings were retained when intelligence quotient (IQ) was entered as a correlated factor. The findings support a cascading developmental pathway to ADHD symptoms mediated by early-onset and severe epilepsy in the first 2 years of life. This warrants detailed investigation of seizure characteristics and cognitive and behavioral sequelae associated with ADHD from early in life, to further the understanding of the association between ADHD and early-onset epilepsy across syndromic and non-syndromic populations.

The Association Between Persistence and Change in Behavioral Difficulties During Early to Middle Childhood and Cognitive Abilities at Age 8.

We investigated the association between persistence and change in behavioral difficulties during early to middle childhood and several cognitive outcomes. We observed 3904 8-year-olds enrolled in the longitudinal study Growing Up in New Zealand (50% male/female; 23% Maori, 9% Pacific Peoples, 13% Asian, 2% Middle Eastern/Latin American/African, 9% Other, 43% European). The NIH Toolbox Cognition Battery was used to assess cognitive functioning at 8 years and the Strengths and Difficulties Questionnaire for behavioral difficulties at 4.5 and 8 years. Multivariate logistic regression analyses were conducted, controlling for well-known sociodemographic confounders. Children with persistent or later onset of behavioral difficulties were at higher risk for poorer vocabulary, reading, inhibitory control/attention, episodic memory, working memory and processing speed at age 8 compared to children with no or improved difficulties. Our study supports the importance of addressing both cognitive and behavioral aspects when planning educational programmes and interventions in early and middle childhood.

Perinatal adversities in tuberous sclerosis complex: Determinants and neurodevelopmental outcomes.

AIM: To examine the association between perinatal adversities and neurodevelopmental outcome in tuberous sclerosis complex (TSC). METHOD: The Tuberous Sclerosis 2000 study is a prospective, longitudinal UK study of TSC. In phase 1, mutation type, TSC family history, tuber characteristics, presence of cardiac rhabdomyomas, seizure characteristics, and intellectual ability were assessed in 125 children affected with TSC (64 females, 61 males; median age 39mo, range 4-254). In phase 2, 88 participants (49 females, 39 males; median age 148mo, range 93-323) were assessed for neurodevelopmental outcomes including intellectual ability, autism spectrum disorder, and attention-deficit/hyperactivity disorder. Perinatal histories of 88 participants with TSC and 80 unaffected siblings were collected retrospectively using the Obstetric Enquiry Schedule and coded with a modified Gillberg Optimality Scale to measure levels of perinatal adversity. Data were analysed using Mann-Whitney U tests, Spearman's rank correlation, and linear regression with robust standard errors. RESULTS: Children with familial TSC experienced significantly greater perinatal adversity than unaffected siblings. Perinatal adversity was higher in children with TSC-affected mothers than those with unaffected mothers. There was no significant association between perinatal adversities and neurodevelopmental outcomes after controlling for confounders. INTERPRETATION: Maternal TSC is a significant marker of elevated perinatal risk in addition to risks incurred by fetal genotype. Pregnancies complicated by maternal or fetal TSC require higher vigilance, and mechanisms underlying increased perinatal adversity require further research. WHAT THIS PAPER ADDS: Higher perinatal adversity is associated with familial tuberous sclerosis complex (TSC). Maternal TSC was associated with higher frequencies of several perinatal risk markers. Paternal TSC was not associated with higher levels of perinatal adversity. Perinatal adversity levels in TSC1 and TSC2 subgroups did not differ significantly. Perinatal adversities were not associated with neurodevelopmental outcomes.

Prisoners with Attention Deficit Hyperactivity Disorder: co-morbidities and service pathways.

PURPOSE: This paper aims to examine effective diagnostic and treatment pathways for attention deficit hyperactivity disorder (ADHD) in prison settings given the high prevalence of ADHD and comorbidities in the prison population. DESIGN/METHODOLOGY/APPROACH: Two studies were carried out in two separate prisons in London. Firstly, data were collected to understand the prevalence of ADHD and the comorbidities. The second study used quality improvement (QI) methodology to assess the impact of a diagnostic and treatment pathway for prisoners with ADHD. FINDINGS: Of the prisoners, 22.5% met the diagnostic criteria for ADHD. Nearly half of them were screened positive for autistic traits, with a higher prevalence of mental disorders among prisoners with ADHD compared to those without. The QI project led to a significant increase in the number of prisoners identified as requiring ADHD assessment but a modest increase in the number of prisoners diagnosed or treated for ADHD. ORIGINALITY/VALUE: Despite various challenges, an ADHD diagnostic and treatment pathway was set up in a prison using adapted QI methodology. Further research is needed to explore the feasibility of routine screening for ADHD in prison and examine at a national level the effectiveness of current ADHD prison pathways.

Self-harm and Mental Health Characteristics of Prisoners with elevated rates of autistic traits.

BACKGROUND: Prevalence studies among prisoners have found rates of 1-4% for autism spectrum disorder (ASD) or autistic traits. However, little is known about those prisoners with high levels of autistic traits. AIM: This aim of this study was to compare the mental health characteristics of prisoners with autistic traits with neurotypical prisoners not screening positive for neurodevelopmental disorders. METHOD: The study recruited 240 male prisoners from a London prison and screened for autism spectrum disorder using the Autism Quotient (AQ) 20 and 10, and Autism Diagnostic Observation Schedule (ADOS). The Mini International Neuropsychiatric Interview was used to assess for depression, anxiety, self-harm behavior and suicide. RESULTS: Screening using the AQ identified 46 prisoners with significant autistic traits, with 12 meeting the diagnostic threshold for ASD using the ADOS. Those screening positive with autistic traits were significantly more likely to have thought about self-harm and suicide in the past month than neurotypical prisoners and have a comorbid mental disorder. They were also significantly more likely to report having attempted suicide during their lifetime compared to neurotypical peers at a rate of 64.9 % compared to 11.6 % for the neurotypical prisoners. CONCLUSION: Prisoners with elevated levels of autistic traits were more likely to report self-harm, suicidal thoughts and were more vulnerable to a range of mental disorders than neurotypical prisoners. There is a need for more evidence on the experience of autistic prisoners to inform how pathways should work to improve health outcomes through increased awareness and access to screening and subsequent diagnosis which currently prisons are currently not set up for.

Exploring the Factor Structure of the NIH Toolbox Cognition Battery in a Large Sample of 8-Year-Old Children in Aotearoa New Zealand.

OBJECTIVE: The objective of this study was to derive a factor structure of the measures of the National Institutes of Health (NIH) Toolbox Cognition Battery (CB) that is representative of cognitive abilities in a large ethnically diverse cohort of 8-year-old children in Aotearoa New Zealand. METHODS: Our sample comprised of 4298 8-year-old children from the Growing Up in New Zealand study. We conducted exploratory and confirmatory factor analysis for the NIH Toolbox CB measures to discover the best-fitting factor structure in our sample. Measurement invariance of the identified model was tested across child's gender, socio-economic status (SES), and ethnicity. RESULTS: A three-dimensional factor structure was identified, with one factor of Crystallised Cognition (Reading and Vocabulary), and two distinguished factors of fluid cognition: Fluid Cognition I (Attention/Inhibitory Control, Processing Speed, and Cognitive Flexibility) and Fluid Cognition II (Working Memory, Episodic Memory). The results demonstrate excellent model fit, but reliability of the factors was low. Measurement invariance was confirmed for child's gender. We found configural, but neither metric nor scalar, invariance across SES and the four major ethnic groups: European, Maori, Pacific Peoples, and Asian. CONCLUSION: Our findings show that, at the age of 8 years, fluid abilities are more strongly associated with one another than with crystallised abilities and that fluid abilities need to be further differentiated. This dimensional structure allows for comparisons across child's gender, but evaluations across SES and ethnicity within the Aotearoa New Zealand context must be conducted with caution. We recommend using raw scores of the individual NIH Toolbox CB measures in future research.

Physical Conflict During Pregnancy: A Socioecological, Cross-Cultural Examination of Risk and Protective Factors for New Zealand Women.

Participants were 5,831 women in their third trimester of pregnancy, part of a large, longitudinal, pre-birth national cohort study. Women reported on their experience of pushing and shoving, throwing or breaking objects within their relationship over the past month. Univariable regression models examined the association of a large number of potential risk and protective factors. Those significant at the univariable level were carried forward into final multivariable analyses, stratified by New Zealand's four main ethnic groups: European, Maori, Pacific, and Asian peoples. Relationship commitment, reduced family cohesion, and perceived stress were associated with increased risk across ethnic groups.

Maternal Antenatal Depression and Early Childhood Sleep: Potential Pathways Through Infant Temperament.

OBJECTIVE: Maternal depression is associated with infant and child sleep patterns, and with infant temperament. Here, we examine whether infant temperament mediated an association between maternal antenatal depression and toddler sleep. METHOD: Within the prebirth longitudinal cohort Growing Up in New Zealand, symptoms of antenatal and postnatal depression were measured in 5,568 women using the Edinburgh Postnatal Depression Scale (EPDS). Infant temperament was measured at age 9 months using the Very Short Form of Infant Behavior Questionnaire-Revised (IBQ-R VSF). Sleep duration and nighttime awakenings were reported by parents when children were 2 years old. RESULTS: Independent associations of maternal depression with child sleep patterns at age 2 years, adjusted for maternal demographics, physical health, family relationships, and child health and feeding, were determined using multivariate logistic regression analysis. The odds of having ≥2 nighttime awakenings were increased for children whose mothers had antenatal (1.36, 1.07-1.73) but not postnatal (1.22, 0.88-1.68) or both antenatal and postnatal depression (0.89, 0.56-1.36). There was no association of maternal depression with shorter sleep duration. Two of five dimensions of infant temperament (fear and negative affect) were associated with both antenatal depression scores and increased nighttime awakenings. Mediation analyses controlling for postnatal depression and other predictors of child sleep supported an indirect pathway of antenatal depression to child sleep through infant temperamental negative affectivity. CONCLUSION: Antenatal depression is independently associated with more frequent nighttime awakenings in early childhood. Findings support an indirect pathway through infant negative affect characteristics.

The Association Between Persistence and Change in Early Childhood Behavioural Problems and Preschool Cognitive Outcomes.

The link between behavioural and cognitive difficulties is well established. However, research is limited on whether persistence and change in behavioural difficulties relates to cognitive outcomes, particularly during preschool. We used a large New Zealand birth cohort to investigate how persistence and change in serious behavioural problems from ages 2 to 4.5 years related to measures of cognitive delay at 4.5 years (n = 5885). Using the Strengths and Difficulties total problems score at each time point, children were categorised as showing no difficulties, improved behaviour, concurrent difficulties, and persistent difficulties. Cognitive measures assessed included receptive language, early literacy ability, and executive control. Our results showed that children with concurrent and persistent behavioural difficulties were at a greater risk of showing delays within specific cognitive domains relative to children with no difficulties and were also more likely to show comorbid delays across multiple cognitive domains.

Long-term cognitive outcomes in tuberous sclerosis complex.

AIM: To investigate the interdependence between risk factors associated with long-term intellectual development in individuals with tuberous sclerosis complex (TSC). METHOD: The Tuberous Sclerosis 2000 Study is a prospective longitudinal study of individuals with TSC. In phase 1 of the study, baseline measures of intellectual ability, epilepsy, cortical tuber load, and mutation were obtained for 125 children (63 females, 62 males; median age=39mo). In phase 2, at an average of 8 years later, intellectual abilities were estimated for 88 participants with TSC and 35 unaffected siblings. Structural equation modelling was used to determine the risk pathways from genetic mutation through to IQ at phase 2. RESULTS: Intellectual disability was present in 57% of individuals with TSC. Individuals without intellectual disability had significantly lower mean IQ compared to unaffected siblings, supporting specific genetic factors associated with intellectual impairment. Individuals with TSC who had a slower gain in IQ from infancy to middle childhood were younger at seizure onset and had increased infant seizure severity. Structural equation modelling indicated indirect pathways from genetic mutation, to tuber count, to seizure severity in infancy, through to IQ in middle childhood and adolescence. INTERPRETATION: Early-onset and severe epilepsy in the first 2 years of life are associated with increased risk of long-term intellectual disability in individuals with TSC, emphasizing the importance of early and effective treatment or prevention of epilepsy. WHAT THIS PAPER ADDS: Intellectual disability was present in 57% of individuals with tuberous sclerosis complex (TSC). Those with TSC without intellectual disability had significantly lower mean IQ compared to unaffected siblings. Earlier onset and greater severity of seizures in the first 2 years were observed in individuals with a slower gain in intellectual ability. Risk pathways through seizures in the first 2 years predict long-term cognitive outcomes in individuals with TSC.

Effects of Home Language Environment and Household Crowding on Early Expressive Language Development.

OBJECTIVE: This study examined prospective associations of the home language environment (HLE) and household crowding with expressive language development in 2-year-old children using the data from the Growing Up in New Zealand study, a population-based prospective cohort study. METHODS: A total of 5960 children were included. The HLE (playing games, talking in everyday activities, playing with toys, singing songs, and reading books) and household crowding were measured when the children were 9 months old. Language development was assessed using the MacArthur-Bates Communicative Development Inventories (CDIs)-II short form (A) at age 2 years. Maternal and child characteristics were measured antenatally and when the children were 9 months old. RESULTS: Each HLE activity was associated with higher language scores. A high HLE score, defined as doing at least 3 of the 5 HLE activities at least once daily, was associated with an increase in the language score of 6.31 units (95% confidence interval [CI] 5.00 to 7.62, p < 0.0001). The effect of the HLE was less pronounced in more crowded homes (coefficient = -2.24, 95% CI -0.47 to 4.97, p = 0.106) compared with less crowded homes with at least one other child (coefficient = 6.19, 95% CI 4.28 to 8.10, p < 0.0001) or with no other children (coefficient = 8.19, 95% CI 5.69 to 10.70, p < 0.0001). CONCLUSION: These findings underscore the need to consider various aspects of the home environment in future interventions aiming to facilitate language development in young children.

Antenatal determinants of early childhood talking delay and behavioural difficulties.

The determinants of talking delay alone or its comorbidity with behavioural difficulties was examined in 5768 two-year-old members of the Growing Up in New Zealand longitudinal study. Using the MacArthur-Bates Communicative Development inventories and the total difficulties score from the preschool Strengths and Difficulties Questionnaire, a composite measure was created so that children were categorised as showing no language or behavioural concerns (72.5%), behavioural only difficulties (6.1%), language only difficulties (18.1%), and comorbid language and behavioural difficulties (3.3%). Analyses revealed that antenatal factors such as maternal perceived stress, inadequate folate intake, vitamin intake, alcohol consumption during the first trimester and maternal smoking all had a significant effect on child outcomes. In particular, low multivitamin intake and perceived stress during pregnancy were associated with coexisting language and behavioural difficulties. These findings support international research in showing that maternal factors during pregnancy are associated with developmental outcomes in the early childhood period, and demonstrate these associations within a NZ context. Interventions which address maternal stress management and health behaviours during pregnancy could be beneficial to offspring development.

Persistence and change in behavioural problems during early childhood.

BACKGROUND: Behavioural problems and psychopathology can present from as early as the preschool period. However there is evidence that behavioural difficulties may not be stable over this period. Therefore, the current study was interested in evaluating the persistence and change in clinically relevant behavioural problems during early childhood in a population-based New Zealand birth cohort. METHODS: Behaviour was assessed in 5896 children when they were aged 2 and 4.5 years using the Strengths and Difficulties Questionnaire (SDQ). Correlations and mean differences in subscale and total difficulties scores were examined. Scores were then dichotomised into normal/borderline and abnormal ranges to evaluate the persistence and change in significant behavioural problems. Chi-square analyses and ANOVAs were used to determine the association between sociodemographic and birth variables, and preschool behavioural stability. RESULTS: Raw scores at ages 2 and 4.5 years were moderately correlated, with most measures showing a small but significant decrease in mean scores over time. The majority of children who showed abnormal behaviour at 2 years improved at 4.5 years (57.9% for total difficulties). However, a notable proportion persisted in their difficulties from 2 to 4.5 years (42.1% for total difficulties). There was a small percentage of children who were categorised as abnormal only at 4.5 years. Children with difficulties at one or both time points had a greater proportion who were the result of an unplanned pregnancy, lived in highly deprived urban areas, and had mothers who were younger, of Maori and Pacific ethnicity and were less educated. CONCLUSIONS: Not all children who show early behavioural difficulties persist in these difficulties. Those whose difficulties persist were more likely to experience risk factors for vulnerability relative to children with no difficulties. Results suggest that repeated screening for early childhood behavioural difficulties is important.

A longitudinal study of antenatal and perinatal risk factors in early childhood cognition: Evidence from Growing Up in New Zealand.

BACKGROUND: Poor maternal health, disadvantageous exposures during pregnancy and unfavourable perinatal events are associated with adverse trajectories in offspring cognitive development. AIM: To examine longitudinal associations between antenatal maternal, perinatal and maternal health characteristics and children's early cognitive development across executive control, motor ability and receptive language domains. STUDY DESIGN, SUBJECTS AND OUTCOME MEASURES: Analyses comprised interview and observational data from 4587 children and their mothers enrolled in the longitudinal Growing Up in New Zealand cohort study. Children's executive control (Luria hand clap task), motor skills (mothers' report) and receptive language ability (Peabody Picture Vocabulary Test) were assessed at age 4.5 years. Multivariate logistic regression analyses were conducted, controlling for sociodemographic factors. RESULTS: Smoking pre- and during pregnancy, no folate intake during first trimester and low birth weight were risk factors for poorer executive control. Perceived stress during pregnancy, no folate intake during first trimester and low birth weight were all risk factors for poorer motor ability. Smoking pre-pregnancy, antenatal anxiety and no folate intake during first trimester were risk factors for poorer receptive language ability. CONCLUSION: Adverse ante- and perinatal environments are associated with poorer executive control, motor and receptive language abilities in early childhood. Improving maternal education and support especially for more disadvantaged mothers during pregnancy may reduce the potential deleterious impact of adverse ante- and perinatal conditions on children's early cognition.

Antenatal and Postnatal Determinants of Behavioural Difficulties in Early Childhood: Evidence from Growing Up in New Zealand.

Behavioural difficulties during early childhood have significant implications for multiple outcomes later in life. Child behavioural difficulties at 2 years of age (N = 6246) were assessed by mothers enrolled in a longitudinal, population-based New Zealand cohort study. 10.1% of children had total difficulties scores in the abnormal range on the preschool version of the Strengths and Difficulties Questionnaire. After controlling for maternal education, poverty, and child's birth age/weight, several antenatal and postnatal maternal health and family risk factors were significant for: (i) emotional problems (antenatal maternal perceived stress, lack of periconceptional folate, and moderate to severe maternal postnatal anxiety); (ii) hyperactivity-inattention (antenatal maternal perceived stress, mothers' antenatal exposure to secondhand smoke, moderate to severe maternal postnatal anxiety, and low maternal self-evaluation); (iii) conduct problems and total difficulties (antenatal maternal perceived stress, verbal inter-parental conflict and low maternal self-evaluation). The identification of risk and protective factors associated with early childhood difficulties are vital for guiding intervention and prevention efforts.