Prenatal Stress and Early Childhood Body Mass Index: A Path Analysis Approach

OBJECTIVES

Stress experienced by mothers during the prenatal period can have negative impacts on offspring development. Elevated BMI in childhood in response to early stress experience is a particularly critical outcome of interest since high BMI in childhood is associated with diabetes, heart disease and stroke in later life. The primary objective of this study was to analyze pathways between prenatal stress and early childhood BMI at 54-months of age and to begin to explore ethnic variations in these pathways.

METHODS

This study used the Growing Up in New Zealand (GUiNZ) dataset, which is a longitudinal, representative birth cohort study that began with recruiting pregnant women in 2009 and 2010 in Auckland, New Zealand. Path analysis modeling was used to explore risk and protective pathways between prenatal maternal stress and early childhood body mass index (BMI) at 54-months of age and differences by ethnicity (n = 5510).

RESULTS

Prenatal stress was positively associated with early childhood BMI at 54-months and maternal nutrition behaviors and length of exclusive breastfeeding mediated this direct relationship (χ² (1) = 0.83, p = 0.36; AIC = 50,496). Mediation and moderation paths varied by ethnicity.

CONCLUSIONS FOR PRACTICE

These findings contribute to the understanding of the intergenerational transmission of stress with respect to early childhood obesity. Reducing early stress exposure and/or addressing mediating and moderating factors linking stress experience with obesity development may prove to be more effective than attempting to alter health behaviors and trajectories in adulthood.

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, Māori, Pacific, and Asian peoples. Relationship commitment, reduced family cohesion, and perceived stress were associated with increased risk across ethnic groups.

Effects of heavy rainfall on waterborne disease hospitalizations among young children in wet and dry areas of New Zealand

Heavy rainfall is associated with increased risk of waterborne disease. However, it is not known whether the risk increment differs between wet and dry regions. We examined this question in New Zealand, which has a wide geographical variation of annual rainfall totals (10^th-90^th percentile difference ≥3000 mm). We conducted a nested case-crossover study within a prospective child cohort (born in 2009-2010) for assessing transient health effects when modified by longitudinal exposures to rainfall. Short-term heavy rainfall effects on hospitalizations due to enteric bacterial and viral infectious causes at lag of 0-14 days were assessed using a Cox regression model adjusted for daily temperature, relative humidity and evapotranspiration. We derived quantiles of time-weighted long-term rainfall levels at the children's homes and these were added as an interaction term to the short-term effect model. Hospitalization risks were higher two days after heavy rainfall days (hazard ratio [95% confidence interval]: 1.73 [1.10-2.70]). The lowest-observable-adverse-effect-level was detected at the 94^th percentile of daily rainfall total. Hospital admissions 1-2 days after heavy rainfall increased most in locations with the lowest and highest long-term rainfall. An interaction of this kind between short-term weather and long-term climate has not been reported previously. It is relevant to climate change risk assessments given global projections of increasing intensity of precipitation, against a background of more severe, and possibly more frequent, droughts and flooding.

Patterns of Exposure to Cumulative Risk Through Age 2 and Associations with Problem Behaviors at Age 4.5: Evidence from Growing Up in New Zealand

Exposure to cumulative risk (CR) has important implications for child development, yet little is known about how frequency, persistence, and timing of CR exposure during early childhood predict behavioral problems already before school start. We examine prospective longitudinal associations between patterns of CR exposure from third trimester through 2 years and subsequent behavior problems at 4.5 years. In 6156 diverse children in the Growing Up in New Zealand longitudinal study, the presence of 12 risk factors, spanning maternal health, social status, and home and neighborhood environment, defined CR and were assessed at last trimester and 9 months and 2 years of age. At child age 4.5 years, mothers completed the Strengths and Difficulties Questionnaire, where a score ≥ 16 indicated an abnormal level of problem behaviors (ALPB). Children exposed to a CR ≥ 1 at least once in early development, compared to those with consistent CR = 0, showed a significantly higher likelihood of ALPB at 4.5 years. Consistent high exposure to CR ≥ 4 across all three assessments had the highest prevalence (44%) of ALPB at age 4.5. Children with high CR exposure on two of three, compared to on all three, time points in early development did not evidence a significantly reduced prevalence (32%-41%) of ALPB. The common co-occurrence of risk factors and their significant developmental impact when accumulated early in life underscore the need for systematic multisector intervention and policy implementation during pregnancy and shortly after birth to improve outcomes for vulnerable children.

Comparison of Acetaminophen (Paracetamol) With Ibuprofen for Treatment of Fever or Pain in Children Younger Than 2 Years: A Systematic Review and Meta-analysis

IMPORTANCE

Acetaminophen (paracetamol) and ibuprofen are the most widely prescribed and available over-the-counter medications for management of fever and pain in children. Despite the common use of these medications, treatment recommendations for young children remain divergent.

OBJECTIVE

To compare acetaminophen with ibuprofen for the short-term treatment of fever or pain in children younger than 2 years.

DATA SOURCES

Systematic search of the databases MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials and the trial registers ClinicalTrials.gov and the Australian New Zealand Clinical Trials Registry from inception to March 2019, with no language limits.

STUDY SELECTION

Studies of any design that included children younger than 2 years and directly compared acetaminophen with ibuprofen, reporting antipyretic, analgesic, and/or safety outcomes were considered. There were no limits on length of follow-up.

DATA EXTRACTION AND SYNTHESIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline, 2 authors independently extracted data and assessed quality. Data were pooled using a fixed-effects method if I2 was less than 50% and using a random-effects method if I2 was 50% or greater.

MAIN OUTCOMES AND MEASURES

The primary outcomes were fever or pain within 4 hours of treatment onset. Safety outcomes included serious adverse events, kidney impairment, gastrointestinal bleeding, hepatotoxicity, severe soft tissue infection, empyema, and asthma and/or wheeze.

RESULTS

Overall, 19 studies (11 randomized; 8 nonrandomized) of 241 138 participants from 7 countries and various health care settings (hospital-based and community-based) were included. Compared with acetaminophen, ibuprofen resulted in reduced temperature at less than 4 hours (4 studies with 435 participants; standardized mean difference [SMD], 0.38; 95% CI, 0.08-0.67; P = .01; I2 = 49%; moderate quality evidence) and at 4 to 24 hours (5 studies with 879 participants; SMD, 0.24; 95% CI, 0.03-0.45; P = .03; I2 = 57%; moderate-quality evidence) and less pain at 4 to 24 hours (2 studies with 535 participants; SMD, 0.20; 95% CI, 0.03-0.37; P = .02; I2 = 25%; moderate-quality evidence). Adverse events were uncommon. Acetaminophen and ibuprofen appeared to have similar serious adverse event profiles (7 studies with 27 932 participants; ibuprofen vs aceteminophen: odds ratio, 1.08; 95% CI, 0.87-1.33; P = .50, I2 = 0%; moderate-quality evidence).

CONCLUSIONS AND RELEVANCE

In this study, use of ibuprofen vs acetaminophen for the treatment of fever or pain in children younger than 2 years was associated with reduced temperature and less pain within the first 24 hours of treatment, with equivalent safety.

Multimorbidity in Early Childhood and Socioeconomic Disadvantage: Findings From a Large New Zealand Child Cohort

OBJECTIVE

In contrast with multimorbidity during adulthood, the relationship of childhood multimorbidity with socioeconomic position (SEP) is poorly understood. We aimed to describe early childhood multimorbidity and investigate the relationship of this with SEP.

METHODS

Within a diverse prospective child cohort study, we determined associations of SEP with multimorbidity (defined as the presence of 2 or more chronic conditions) at age 2 years. Maternal SEP was ranked into 5 categories using an index constructed from variables collected antenatally describing maternal education, employment, financial stress, beneficiary status, housing tenure, overcrowding, and residential mobility. Missing values were handled using multiple imputation with chained equations. Independent associations of SEP with multimorbidity were described using adjusted odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Of the 6822 women and 6853 children who were enrolled into the cohort study, 5737 (84%) mother-child dyads had complete antenatal data and were interviewed at age 2 years. Of these 5737, for 3826 (67%) dyads, there were complete data for all variables. Multimorbidity was present in 374/3838 (9.7%) of the cohort children. After multiple imputation and adjustment for maternal ethnicity, smoking, poor health, depressive symptoms, and child gender, the odds of multimorbidity being present were increased for children of mothers in the most (OR 1.74, 95% CI 1.16-2.59) and second most (OR 1.43, 95% CI 1.00-2.04) versus the least disadvantaged group.

CONCLUSION

The odds of multimorbidity are increased for children whose mothers have lower SEP. Cumulative socioeconomic disadvantage increases the potential for a chronic illness trajectory to develop in early childhood.

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.

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 depression symptoms in Pacific women: evidence from Growing Up in New Zealand

INTRODUCTION Pacific women in New Zealand (NZ) have higher rates of antenatal depression than women from other ethnic groups. AIM To identify factors that are significantly associated with depression symptoms in pregnant Pacific women living in NZ. METHODS Data were collected from 5657 pregnant women, 727 of whom identified their ethnicity as Pacific Island. Antenatal depression symptoms were measured using the Edinburgh Depression Scale with scores above 12 indicating elevated antenatal depression symptoms (ADS). RESULTS Pacific women had significantly higher rates of ADS than non-Pacific women, with 23% of pregnant Pacific women experiencing ADS. Factors associated with ADS for Pacific women included age <25 years, moderate to severe nausea during pregnancy, perceived stress, family stress and relationship conflict. Not seeing the importance of maintaining one's Pacific culture and traditions and negative feelings towards NZ culture were also significantly associated with ADS in Pacific women. One in three Pacific women aged <25 years experienced ADS. Pregnant Pacific women without a family general practitioner (GP) before their pregnancy were 4.5-fold more likely to experience ADS than non-Pacific women with a regular GP. DISCUSSION Further attention is required to providing appropriate primary health care for Pacific women of child-bearing age in NZ. Better screening processes and a greater understanding of effective antenatal support for Pacific women is recommended to respond to the multiple risk factors for antenatal depression among Pacific women.

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.

Dietary Patterns and Dietary Adaptations in Women with and without Gestational Diabetes: Evidence from the Growing Up in New Zealand Study

Diet is a cornerstone of the management of gestational diabetes (GDM). We investigated differences in dietary patterns and dietary adaptations among pregnant women with and without GDM participating in the Growing Up in New Zealand study. Presence of GDM was determined using coded clinical data and plasma glucose results meeting the New Zealand Society for the Study of Diabetes diagnostic criteria. Women answered a food frequency questionnaire and questions regarding dietary changes and information received during pregnancy. Women with GDM had lower adherence scores than those without GDM for 'Junk' (mean (SD) score -0.28 (0.95) versus 0.02 (1.01) p < 0.0005) and 'Traditional/White bread' dietary patterns (-0.18 (0.93) versus 0.01 (1.01) p = 0.002). More women with GDM reported avoiding foods high in fat or sugar (25.3% versus 5.7%, p < 0.05) compared to women without GDM. A greater proportion of women with GDM compared with those without GDM received information from dietitians or nutritionists (27.0% versus 1.7%, p < 0.05) or obstetricians (12.6% versus 7.5%, p < 0.05). More women diagnosed before the antenatal interview received advice from dietitians or nutritionists compared with those diagnosed after (46.9% versus 6.0%, p < 0.05). Women with GDM appear to make positive changes to their diet in response to advice received from health care professionals.

Association of Repeated Antibiotic Exposure Up to Age 4 Years With Body Mass at Age 4.5 Years

IMPORTANCE

Antibiotic exposures in early life may affect weight by altering gut microbiota, potentially increasing the likelihood of childhood obesity.

OBJECTIVE

To examine whether repeated antibiotic exposure by age 48 months is associated with higher body mass index (BMI) at age 54 months.

DESIGN, SETTING, AND PARTICIPANTS

This research was undertaken within a prospective cohort study in New Zealand (Growing Up in New Zealand) that recruited 6853 children antenatally during 2009 to 2010. At the 54-month follow-up, 5734 of 6156 children (93%) had their weight and height measured. Community pharmacy antibiotic dispensing data were obtained from the New Zealand Pharmaceutical Collection database for children whose parents consented to external data linkage. The analytic sample comprised singletons with 54-month weight and height measurements, community antibiotic dispensing and birth weight data, gestational age greater than 27 weeks, and no congenital anomalies. Data analysis took place from 2017 to 2018.

EXPOSURES

Antibiotic exposure (yes or no), the number of dispensings, age at first exposure, and timing (age) of exposures between birth and age 48 months.

MAIN OUTCOMES AND MEASURES

World Health Organization BMI-for-age z scores; and International Obesity Task Force overweight and obesity cutoff points that pass through adult BMI values of 25 and 30.

RESULTS

Of the 5128 singletons (2622 [51%] male; mean [SD] birth weight of 3527 [542] g), 4886 (95%) had an antibiotic prescription by age 48 months and 437 (9%) had obesity at age 54 months. Adjusted mean (SE) BMI-for-age z scores increased significantly with the number of antibiotic dispensings for 4 to 6, 7 to 9, and more than 9 dispensings (unexposed, 0.87 [0.09]; 1-3 exposures, 0.92 [0.06] [P = .57]; 4-6 exposures, 1.06 [0.06] [P = .02]; 7-9 exposures, 1.06 [0.06] [P = .02]; >9 exposures, 1.08 [0.05] [P = .01]). Additionally, receiving more than 9 dispensings was associated with greater likelihood of obesity compared with no exposure (adjusted odds ratio, 2.41; 95% CI, 1.07-5.41). Children whose exposure began in the first year of life had a higher adjusted mean (SD) BMI-for-age z score than those not exposed (1.06 [0.05] vs 0.89 [0.09]; P = .03), whereas those whose exposure commenced after the first year of life did not (1.02 [0.06] vs 0.89 [0.09]; P = .10).

CONCLUSIONS AND RELEVANCE

In this study, repeated antibiotic exposure in early childhood was associated with higher mean BMI-for-age z score and an increased likelihood of obesity. Future research could examine whether interventions such as antibiotic stewardship programs, which are designed to reduce overprescribing of antibiotics, also reduce early childhood obesity.

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.

Prevalence of gestational diabetes according to commonly used data sources: an observational study

Background

It is well recognized that prevalence of gestational diabetes mellitus (GDM) varies depending on the population studied and the diagnostic criteria used. The data source used also can lead to substantial differences in the reporting of GDM prevalence but is considered less frequently. Accurate estimation of GDM prevalence is important for service planning and evaluation, policy development, and research. We aimed to determine the prevalence of GDM in a cohort of New Zealand women using a variety of data sources and to evaluate the agreement between different data sources.

Methods

A retrospective analysis of prospectively collected data from the Growing Up in New Zealand Study, consisting of a cohort of 6822 pregnant women residing in a geographical area defined by three regional health boards in New Zealand. Prevalence of GDM was estimated using four commonly used data sources. Coded clinical data on diabetes status were collected from regional health boards and the Ministry of Health’s National Minimum Dataset, plasma glucose results were collected from laboratories servicing the recruitment catchment area and coded according to the New Zealand Society for the Study of Diabetes diagnostic criteria, and self-reported diabetes status collected via interview administered questionnaires. Agreement between data sources was calculated using the proportion of agreement with 95% confidence intervals for both a positive and negative diagnosis of GDM.

Results

Prevalence of GDM combining data from all sources in the Growing Up in New Zealand cohort was 6.2%. Estimates varied from 3.8 to 6.9% depending on the data source. The proportion of agreement between data sources for presence of GDM was 0.70 (95% CI 0.65, 0.75). A third of women who had a diagnosis of GDM according to medical data reported having no diabetes in interview administered questionnaires.

Conclusion

Prevalence of GDM varies considerably depending on the data source used. Health services need to be aware of this and to understand the limitations of local data sources to ensure service planning and evaluation, policy development and research are appropriate for the local prevalence. Improved communication of the diagnosis may assist women’s self-management of GDM.

Caesarean section delivery and childhood obesity: evidence from the growing up in New Zealand cohort

Background

Epidemiological studies have reported conflicting results in the association between Caesarean section (CS) birth and childhood obesity. Many of these studies had small sample sizes, were unable to distinguish between elective/planned and emergency CS, and did not adjust for the key confounder maternal pre-pregnancy body mass index (BMI). We investigated the association between CS delivery, particularly elective/planned and childhood obesity, using the Growing Up in New Zealand prospective longitudinal cohort study.

Methods

Pregnant women planning to deliver their babies on the New Zealand upper North Island were invited to participate. Mode of delivery was categorised into spontaneous vaginal delivery (VD) (reference), assisted VD, planned CS and emergency CS. The main outcome was childhood obesity defined according to the International Obesity Taskforce criteria at age 24 and 54 months. Multinomial logistic regression and mixed-effects linear regression models were fitted with associations adjusted for several potential confounders.

Results

Of the 6599 infants, 1532 (23.2%) were delivered by CS. At age 24 months, 478 (9.3%) children were obese. There was a statistically significant association between planned CS adjusted relative risk ratio (aRRR=1.59; (95% CI 1.09 to 2.33)) and obesity but not for emergency CS (aRRR=1.27; (95% CI 0.89 to 1.82)). At age 54 months there was no association between planned CS (aRRR=0.89; (95% CI 0.54 to 1.45)) and obesity as well as for emergency CS (aRRR=1.19; (95% CI 0.80 to 1.77)). At all-time points those born by planned CS had a higher mean BMI (adjusted mean difference=0.16; (95% CI 0.00 to 0.31), p=0.046).

Conclusions

Planned CS was an independent predictor of obesity in early childhood. This suggests that birth mode influences growth, at least in the short term. This association occurred during a critical phase of human development, the first 2 years of life, and if causal might result in long-term detrimental cardiometabolic changes.

Maternal experiences of ethnic discrimination and subsequent birth outcomes in Aotearoa New Zealand

Background

Interpersonal discrimination experience has been associated with adverse birth outcomes. Limited research has evaluated this relationship within multicultural contexts outside the United States where the nature and salience of discrimination experiences may differ. Such research is important in order to help identify protective and risk factors that may mediate the relationship between discrimination experience and adverse birth outcomes.

Methods

Evaluated the relationship between perceived discrimination, as measured in pregnancy, with birth weight and gestation length among Māori, Pacific, and Asian women from Aotearoa New Zealand (N = 1653).

Results

Thirty percent of the sample reported some type of unfair treatment that they attributed to their ethnicity. For Māori women specifically, unfair treatment at work (β = − 243 g) and in acquiring housing (β = − 146 g) were associated with lower birth weight when compared to Māori women not experiencing these types of discrimination, while an ethnically motivated physical attack (β = − 1.06 week), and unfair treatment in the workplace (β = − 0.95 week), in the criminal justice system (β = − 0.55 week), or in banking (β = − 0.73 week) were associated with significantly shorter gestation.

Conclusions

Despite a high prevalence of discrimination experience among women from all ethnic groups, discrimination experience was a strong predictor of lower birth weight and shorter gestation length among indigenous Māori women only. Additional research is needed to better understand the risk and protective factors that may moderate the relationship between discrimination experience and adverse birth outcomes among women from different ethnic groups.

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 Māori 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.

Ethnic Disparities in Childhood Prevalence of Maltreatment: Evidence From a New Zealand Birth Cohort

Objectives. To document ethnic disparities in childhood abuse and neglect among New Zealand children.Methods. We followed the 1998 New Zealand birth cohort of 56 904 children through 2016. We determined the cumulative childhood prevalence of reports to child protective services (CPS), substantiated maltreatment (by subtype), and out-of-home placements, from birth to age 18 years, by ethnic group. We also developed estimates stratified by maternal age and community deprivation levels.Results. We identified substantial ethnic differences in child maltreatment and child protection involvement. Both Māori and Pacific Islander children had a far greater likelihood of being reported to CPS, being substantiated as victims, and experiencing an out-of-home placement than other children. Across all levels of CPS interactions, rates of Māori involvement were more than twice those of Pacific Islander children and more than 3 times those of European children.Conclusions. Despite long-standing child support policies and reparation for breaches of Indigenous people's rights, significant child maltreatment disparities persist. More work is needed to understand how New Zealand's public benefit services can be more responsive to the needs of Indigenous families and their children.

Telomere length in early childhood is associated with sex and ethnicity

Telomeres are repetitive DNA sequences at the end of chromosomes that function to protect chromosomes from degradation. Throughout the life course, telomere length decreases with age and is influenced by environmental factors and health conditions. This study aimed to determine the relative telomere lengths in a diverse cohort of about 4000 four-year-old children in New Zealand. Linear regression was used to investigate the relationship between telomere length, child gender, ethnicity, paternal age and deprivation. We observed substantial variation in telomere length according to sex and self-identified ethnicity. Telomere length was longer in females compared to males (coefficient of 0.042, 95% confidence interval (CI) 0.024-0.060). European children had shorter telomere than both the indigenous Māori (coefficient of 0.03, CI 0.007-0.055) and Pacific children (coefficient of 0.15, CI 0.12-0.18). The data suggest that telomere lengths are highly variable and variability between individuals arise from early age, influenced partly by sex and ethnicity. Longer telomeres in indigenous Māori and Pacific children may reflect the heritability of telomere length in genetically less complex populations. This study increases our understanding of telomere dynamics in young children since the majority of telomere studies are conducted in adults.

Child Health CheckPoint: cohort summary and methodology of a physical health and biospecimen module for the Longitudinal Study of Australian Children

OBJECTIVES

'Growing Up in Australia: The Longitudinal Study of Australian Children' (LSAC) is Australia's only nationally representative children's longitudinal study, focusing on social, economic, physical and cultural impacts on health, learning, social and cognitive development. LSAC's first decade collected wide-ranging repeated psychosocial and administrative data; here, we describe the Child Health CheckPoint, LSAC's dedicated biophysical module.

DESIGN, SETTING AND PARTICIPANTS

LSAC recruited a cross-sequential sample of 5107 infants aged 0-1 year and a sample of 4983 children aged 4-5 years in 2004, since completing seven biennial visits. CheckPoint was a cross-sectional wave that travelled Australia in 2015-2016 to reach LSAC's younger cohort at ages 11-12 years between LSAC waves 6 and 7. Parent-child pairs participated in comprehensive assessments at 15 Assessment Centres nationwide or, if unable to attend, a shorter home visit.

MEASURES

CheckPoint's intergenerational, multidimensional measures were prioritised to show meaningful variation within normal ranges and capture non-communicable disease (NCD) phenotype precursors. These included anthropometry, physical activity, fitness, time use, vision, hearing, and cardiovascular, respiratory and bone health. Biospecimens included blood, saliva, buccal swabs (also from second parent), urine, hair and toenails. The epidemiology and parent-child concordance of many measures are described in separate papers.

RESULTS

1874 (54% of eligible) parent-child pairs and 1051 second parents participated. Participants' geographical distribution mirrored the broader Australian population; however, mean socioeconomic position and parental education were higher and fewer reported non-English-speaking or Indigenous backgrounds. Application of survey weights partially mitigates that the achieved sample is less population representative than previous waves of LSAC due to non-random attrition. Completeness was uniformly high for phenotypic data (>92% of eligible), biospecimens (74%-97%) and consent (genetic analyses 98%, accessing neonatal blood spots 97%, sharing 96%).

CONCLUSIONS

CheckPoint enriches LSAC to study how NCDs develop at the molecular and phenotypic levels before overt disease emerges, and clarify the underlying dimensionality of health in childhood and mid-adulthood.

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.

Infant Food Security in New Zealand: A Multidimensional Index Developed from Cohort Data

Food security (FS) during infancy is associated with lifelong outcomes. New Zealand is a developed economy that reports poor childhood nutrition-related health statistics, particularly among minority children, yet has no measure of FS applicable to infancy. The objective was to develop an FS index for New Zealand infants and examine its association with demographic covariates and health outcomes. Within a large (n = 6853) nationally representative cohort, variables describing infant food consumption, breastfeeding, and maternal food-related coping methods were collected from mothers during late infancy. An FS index was derived using confirmatory factor analysis. Associations were assessed by logistic regressions and described using odds ratios (OR) and ≥95% confidence intervals (CI). Fifteen percent of the cohort was highly FS, 43% tenuously food insecure (FIS), and 16% highly food insecure (FIS). Infants from minority ethnic groups had lower odds of being food secure, as did those born to the youngest mothers, mothers who smoked, or those who lived in low-income households. FIS infants had higher odds of morbidity. Interventions to improve infant FS should focus on improving dietary quality, and should give particular consideration to minority infants. We identified that FIS shows wide ethnic and socioeconomic inequity, and is associated with poorer health. The most important driving factors of FIS included poor quality weaning diets, as well as poverty and its proxies. Any interventions to improve infant FS should focus on increasing fruit and vegetable consumption to recommended intake levels, and should give particular consideration to minority infants.

Effects of folic acid food fortification scenarios on the folate intake of a multi-ethnic pregnant population

OBJECTIVE

To simulate effects of different scenarios of folic acid fortification of food on dietary folate equivalents (DFE) intake in an ethnically diverse sample of pregnant women.

DESIGN

A forty-four-item FFQ was used to evaluate dietary intake of the population. DFE intakes were estimated for different scenarios of food fortification with folic acid: (i) voluntary fortification; (ii) increased voluntary fortification; (iii) simulated bread mandatory fortification; and (iv) simulated grains-and-rice mandatory fortification.

SETTING

Ethnically and socio-economically diverse cohort of pregnant women in New Zealand.ParticipantsPregnant women (n 5664) whose children were born in 2009-2010.

RESULTS

Participants identified their ethnicity as European (56·0 %), Asian (14·2 %), Māori (13·2 %), Pacific (12·8 %) or Others (3·8 %). Bread, breakfast cereals and yeast spread were main food sources of DFE in the two voluntary fortification scenarios. However, for Asian women, green leafy vegetables, bread and breakfast cereals were main contributors of DFE in these scenarios. In descending order, proportions of different ethnic groups in the lowest tertile of DFE intake for the four fortification scenarios were: Asian (39-60 %), Others (41-44 %), European (31-37 %), Pacific (23-26 %) and Māori (23-27 %). In comparisons within each ethnic group across scenarios of food fortification with folic acid, differences were observed only with DFE intake higher in the simulated grains-and-rice mandatory fortification v. other scenarios.

CONCLUSIONS

If grain and rice fortification with folic acid was mandatory in New Zealand, DFE intakes would be more evenly distributed among pregnant women of different ethnicities, potentially reducing ethnic group differences in risk of lower folate intakes.

How differing methods of ascribing ethnicity and socio-economic status affect risk estimates for hospitalisation with infectious disease

Significant ethnic and socio-economic disparities exist in infectious diseases (IDs) rates in New Zealand, so accurate measures of these characteristics are required. This study compared methods of ascribing ethnicity and socio-economic status. Children in the Growing Up in New Zealand longitudinal cohort were ascribed to self-prioritised, total response and single-combined ethnic groups. Socio-economic status was measured using household income, and both census-derived and survey-derived deprivation indices. Rates of ID hospitalisation were compared using linked administrative data. Self-prioritised ethnicity was simplest to use. Total response accounted for mixed ethnicity and allowed overlap between groups. Single-combined ethnicity required aggregation of small groups to maintain power but offered greater detail. Regardless of the method used, Māori and Pacific children, and children in the most socio-economically deprived households had a greater risk of ID hospitalisation. Risk differences between self-prioritised and total response methods were not significant for Māori and Pacific children but single-combined ethnicity revealed a diversity of risk within these groups. Household income was affected by non-random missing data. The census-derived deprivation index offered a high level of completeness with some risk of multicollinearity and concerns regarding the ecological fallacy. The survey-derived index required extra questions but was acceptable to participants and provided individualised data. Based on these results, the use of single-combined ethnicity and an individualised survey-derived index of deprivation are recommended where sample size and data structure allow it.

Prenatal alcohol consumption and infant and child behavior: Evidence from the Growing Up in New Zealand Cohort

BACKGROUND

High levels of alcohol exposure during pregnancy can damage developing brains and influence child behavior and learning.

AIM

To examine the effects of lower levels of alcohol and very early exposure to alcohol on infant temperament and child behavior.

STUDY DESIGN, SUBJECTS, AND OUTCOME MEASURES

The Growing Up in New Zealand study involves a prospective birth cohort of 6822 pregnant women of whom 6156 provided information on their child's temperament using the Infant Behavior Questionnaire-Revised (IBQ-R VSF) at 9 months and their child's behavior using the Strengths and Difficulties Questionnaire at 2 years.

RESULTS

A series of adjusted linear regression models controlling for socio-demographic factors found alcohol consumption during pregnancy was most consistently related to Lower Positive Affect, Affiliation/Regulation, and Orienting Capacity temperament scores. Mothers who stopped drinking after becoming aware of their pregnancy, but had an unplanned pregnancy (hence may have a baby exposed to alcohol for longer), also reported infants with lower Orienting Capacity, Affiliation/Regulation, and Fear temperament scores compared to those that did not drink. Children whose mothers drank four or more drinks per week during pregnancy were more likely to report their child as having conduct problems, with higher total difficulties scores at age 2.

CONCLUSIONS

Alcohol consumption during pregnancy has a negative effect especially on infant temperament, even if small amounts of alcohol are consumed. Our findings have implications for men and women who drink, medical professionals, and for the availability of contraception to those who drink, but do not plan to get pregnant.

Determinants of folic acid supplement use outside national recommendations for pregnant women: results from the Growing Up in New Zealand cohort study

OBJECTIVE

To evaluate the sociodemographic and lifestyle factors associated with insufficient and excessive use of folic acid supplements (FAS) among pregnant women.

DESIGN

A pregnancy cohort to which multinomial logistic regression models were applied to identify factors associated with duration and dose of FAS use.

SETTING

The Growing Up in New Zealand child study, which enrolled pregnant women whose children were born in 2009-2010.

SUBJECTS

Pregnant women (n 6822) enrolled into a nationally generalizable cohort.

RESULTS

Ninety-two per cent of pregnant women were not taking FAS according to the national recommendation (4 weeks before until 12 weeks after conception), with 69 % taking insufficient FAS and 57 % extending FAS use past 13 weeks' gestation. The factors associated with extended use differed from those associated with insufficient use. Consistent with published literature, the relative risks of insufficient use were increased for younger women, those with less education, of non-European ethnicities, unemployed, who smoked cigarettes, whose pregnancy was unplanned or who had older children, or were living in more deprived households. In contrast, the relative risks of extended use were increased for women of higher socio-economic status or for whom this was their first pregnancy and decreased for women of Pacific v. European ethnicity.

CONCLUSIONS

In New Zealand, current use of FAS during pregnancy potentially exposes pregnant women and their unborn children to too little or too much folic acid. Further policy development is necessary to reduce current socio-economic inequities in the use of FAS.

Staphylococcus aureus colonisation and its relationship with skin and soft tissue infection in New Zealand children

New Zealand children suffer from high rates of skin and soft tissue infection (SSTI). Staphylococcus aureus colonisation is known to increase the risk of nosocomial infection. We aimed to determine whether S. aureus colonisation also increased the risk of community-onset SSTI. This study, performed within the Growing Up in New Zealand cohort, used interview and administrative data, and bacterial culture results from the nose, throat, and skin swabs collected at 4½ years of age. Multivariable log-binomial regression was used to derive adjusted risk ratios. S. aureus was isolated from 2225/5126 (43.4%) children. SSTI affected 1509/5126 (29.4%) children before age five. S. aureus colonisation at any site was associated with SSTI (aRR = 1.09, 95%CI 1.01-1.19), particularly in the year prior to swab collection (aRR = 1.18, 95%CI 1.02-1.37). The strongest association was between skin colonisation and SSTI within the year prior to swab collection (aRR = 1.47, 95%CI 1.14-1.84). Socioeconomic and ethnic variables remained independent determinants of SSTI. S. aureus colonisation was associated with an increased risk of community-onset SSTI. Socioeconomic and ethnic factors and eczema had independent effects on SSTI risk. Interventions which reduce the prevalence of S. aureus colonisation may be expected to reduce the incidence of community-onset SSTI.

Wear-Time Compliance with a Dual-Accelerometer System for Capturing 24-h Behavioural Profiles in Children and Adults

To advance the field of time-use epidemiology, a tool capable of monitoring 24 h movement behaviours including sleep, physical activity, and sedentary behaviour is needed. This study explores compliance with a novel dual-accelerometer system for capturing 24 h movement patterns in two free-living samples of children and adults. A total of 103 children aged 8 years and 83 adults aged 20-60 years were recruited. Using a combination of medical dressing and purpose-built foam pouches, participants were fitted with two Axivity AX3 accelerometers—one to the thigh and the other to the lower back—for seven 24 h periods. AX3 accelerometers contain an inbuilt skin temperature sensor that facilitates wear time estimation. The median (IQR) wear time in children was 160 (67) h and 165 (79) h (out of a maximum of 168 h) for back and thigh placement, respectively. Wear time was significantly higher and less variable in adults, with a median (IQR) for back and thigh placement of 168 (1) and 168 (0) h. A greater proportion of adults (71.6%) achieved the maximum number of complete days when compared to children (41.7%). We conclude that a dual-accelerometer protocol using skin attachment methods holds considerable promise for monitoring 24-h movement behaviours in both children and adults.

Agreement between Future Parents on Infant Feeding Intentions and Its Association with Breastfeeding Duration: Results from the Growing Up in New Zealand Cohort Study

Maternal intentions are believed to have the strongest influence on infant feeding. However, what has rarely been studied, are the associations of maternal and partner intentions, and the influence these factors have on infant feeding. Our objective was to describe breastfeeding intentions of pregnant women and their partners, agreement about these intentions, and whether this agreement is associated with breastfeeding initiation and duration. This study was completed within the Growing Up in New Zealand study. Agreement between mothers and partners on intended initial infant feeding method was fair (κ = 0.21, 95% confidence interval (CI) 0.17–0.25) as was intended breastfeeding duration (κ = 0.25, 95% CI 0.22–0.28). Infants whose parents agreed antenatally on breastfeeding only were more likely to have been breastfed for >6 months, after adjustment for maternal (odds ratio (OR) = 6.3, 95% CI 3.9–10.2) and partner demographics (OR = 5.7, 95% CI 3.6–9.2). Likewise, infants whose parents agreed antenatally to breastfeed for >6 months were more likely to have been breastfed for >6 months, after adjustment for maternal (OR = 4.9, 95% CI 3.9–6.2) and partner demographics (OR = 5.0, 95% CI 4.0–6.3). Interventions that promote breastfeeding to both mothers and partners which enable parents to reach agreement about intended feeding methods have the potential to increase both breastfeeding initiation and duration.

Community engagement in the Aboriginal Families Study: Strategies to promote participation

BACKGROUND

Aboriginal women and families are under-represented in Australian research on pregnancy and childbirth. The Aboriginal Families Study aimed to investigate the views and experiences of a representative sample of women giving birth to an Aboriginal baby in South Australia between July 2011 and June 2013, using methods designed to respect Aboriginal culture and communities.

METHODS

A team of 12 Aboriginal researchers facilitated community engagement and recruitment of Aboriginal and non-Aboriginal mothers of Aboriginal infants in urban, regional and remote areas of South Australia over a two-year period.

RESULTS

A total of 344 women took part, around a quarter of all Aboriginal women giving birth in South Australia in the study period (39% urban, 35% regional and 25% from remote areas). Participants were representative in relation to maternal age (mean age of 25 years, range=15-43 years). Over half of women (56%) first heard about the study via a member of the fieldwork team making contact with them through community connections. Other major sources of recruitment were: Aboriginal health services/programs (20%) and public maternity hospitals (16%). Almost all of the women (95%) recruited via community networks of the fieldwork team completed the questionnaire. In contrast, 51% of women recruited via public hospitals completed the questionnaire (odds ratio=0.1, 95% confidence interval 0.0-0.1, p<0.001).

CONCLUSIONS

Aboriginal researchers' community knowledge and leadership is critical to the conduct of successful Aboriginal health research. High levels of participation in research by 'harder to reach' populations are achievable when researchers take time to build relationships and work in partnership with communities.

Te Reo Māori: indigenous language acquisition in the context of New Zealand English

This study assessed the status of te reo Māori, the indigenous language of New Zealand, in the context of New Zealand English. From a broadly representative sample of 6327 two-year-olds (Growing Up in New Zealand), 6090 mothers (96%) reported their children understood English, and 763 mothers (12%) reported their children understood Māori. Parents completed the new MacArthur-Bates Communicative Development Inventory short forms for te reo Māori (NZM: CDI sf) and New Zealand English (NZE: CDI sf). Mothers with higher education levels had children with larger vocabularies in both te reo Māori and NZ English. For English speakers, vocabulary advantages also existed for girls, first-borns, monolinguals, those living in areas of lower deprivation, and those whose mothers had no concerns about their speech and language. Because more than 99% of Māori speakers were bilingual, te reo Māori acquisition appears to be occurring in the context of the acquisition of New Zealand English.

Pre-school nutrition-related behaviours at home and early childhood education services: findings from the Growing Up in New Zealand longitudinal study

OBJECTIVE

Pre-school nutrition-related behaviours influence diet and development of lifelong eating habits. We examined the prevalence and congruence of recommended nutrition-related behaviours (RNB) in home and early childhood education (ECE) services, exploring differences by child and ECE characteristics.

DESIGN

Telephone interviews with mothers. Online survey of ECE managers/head teachers.

SETTING

New Zealand.

SUBJECTS

Children (n 1181) aged 45 months in the Growing Up in New Zealand longitudinal study.

RESULTS

A mean 5·3 of 8 RNB were followed at home, with statistical differences by gender and ethnic group, but not socio-economic position. ECE services followed a mean 4·8 of 8 RNB, with differences by type of service and health-promotion programme participation. No congruence between adherence at home and in ECE services was found; half of children with high adherence at home attended a service with low adherence. A greater proportion of children in deprived communities attended a service with high adherence, compared with children living in the least deprived communities (20 and 12 %, respectively).

CONCLUSIONS

Children, across all socio-economic positions, may not experience RNB at home. ECE settings provide an opportunity to improve or support behaviours learned at home. Targeting of health-promotion programmes in high-deprivation areas has resulted in higher adherence to RNB at these ECE services. The lack of congruence between home and ECE behaviours suggests health-promotion messages may not be effectively communicated to parents/family. Greater support is required across the ECE sector to adhere to RNB and promote wider change that can reach into homes.

The Strengths and Difficulties Questionnaire: Factor Structure of the Father-Report and Parent Agreement in 2-Year-Old Children

There is limited research on the preschool version of the Strengths and Difficulties Questionnaire (SDQ), and comparisons between mothers and fathers as informants and whether the factor structure shows measurement invariance across parents is lacking. Our study involved mothers (n = 6,246) and fathers (n = 3,759) of 2-year-old children from the Growing Up in New Zealand birth cohort. Confirmatory factor analysis was used to evaluate the factor structure of the SDQ and test for measurement invariance across mothers and fathers. For fathers, we found support for a modified five-factor model that accounts for a positive construal method effect. Internal consistency was good for measures except peer problems. Full measurement invariance of this modified model was found across mothers and fathers, and parents showed moderate agreement in their SDQ ratings (0.34 ≤ r ≤ 0.44). More research is needed on whether mother- and father-reports differ in sensitivity when screening for early childhood psychiatric disorders.

Emergency department visits of young children and long-term exposure to neighbourhood smoke from household heating - The Growing Up in New Zealand child cohort study

In developed countries, exposure to wood or coal smoke occurs predominantly from neighbourhood emissions arising from household heating. The effect of this exposure on child health is not well characterized. Within a birth cohort study in New Zealand we assessed healthcare events associated with exposure to neighbourhood smoke from household heating. Our outcome measure was non-accidental presentations to hospital emergency departments (ED) before age three years. We matched small area-level census information with the geocoded home locations to measure the density of household heating with wood or coal in the neighbourhood and applied a time-weighted average exposure method to account for residential mobility. We then used hierarchical multiple logistic regression to assess the independence of associations of this exposure with ED presentations adjusted for gender, ethnicity, birth weight, breastfeeding, immunizations, number of co-habiting smokers, wood or coal heating at home, bedroom mold, household- and area-level deprivation and rurality. The adjusted odds ratio of having a non-accidental ED visit was 1.07 [95%CI: 1.03-1.12] per wood or coal heating household per hectare. We found a linear dose-response relationship (p-value for trend = 0.024) between the quartiles of exposure (1st as reference) and the same outcome (odds ratio in 2nd to 4th quartiles: 1.14 [0.95-1.37], 1.28 [1.06-1.54], 1.32 [1.09-1.60]). Exposure to neighbourhoods with higher density of wood or coal smoke-producing households is associated with an increased odds of ED visits during early childhood. Policies that reduce smoke pollution from domestic heating by as little as one household per hectare using solid fuel burners could improve child health.

Antibiotic consumption by New Zealand children: exposure is near universal by the age of 5 years

Background

Increasing concerns about antibiotic resistance and microbiome disruption have stimulated interest in describing antibiotic consumption in young children. Young children are an age group for whom antibiotics are frequently prescribed.

Objectives

To describe community antibiotic dispensing during the first 5 years of life in a large, socioeconomically and ethnically diverse cohort of children, and to determine how antibiotic dispensing varied between population subgroups.

Methods

This study was performed within the Growing Up in New Zealand longitudinal cohort study ( www.growingup.co.nz ) with linkage to national administrative antibiotic dispensing data. Descriptive statistics and univariate and multivariable associations were determined.

Results

The 5581 cohort children received 53 052 antibiotic courses, of which 54% were amoxicillin. By age 5 years, 97% of children had received one or more antibiotic courses, and each child had received a median of eight antibiotic courses (IQR 4-13). The mean incidence of antibiotic dispensing was 1.9 courses/child/year. Multivariable negative binomial regression showed that Māori and Pacific children received more antibiotic courses than European children, as did children in the most-deprived compared with the least-deprived areas. A distinct seasonal pattern was noted.

Conclusions

This study provided a detailed description of antibiotic dispensing within a large and diverse child cohort. Antibiotic exposure was near universal by age 5 years. The predominance of amoxicillin use and the seasonal pattern suggest much antibiotic use may have been for self-limiting respiratory infections. There is a need for safe and effective interventions to improve antibiotic prescribing practices for New Zealand children.

Green Space and Depression during Pregnancy: Results from the Growing Up in New Zealand Study

Background: Antenatal depression is an important contributor to poor maternal health experienced by some women. This study aimed to determine whether exposure to green space during pregnancy is associated with less depression, and whether this association is moderated by relevant factors, such as age, education, self-identified ethnicity, physical activity, residential rurality, and socioeconomic status. Methods: Health data were sourced from the cohort study “Growing Up in New Zealand” comprised of 6772 participants. Green space was estimated based on the proportion of green space within the Census Area Unit. Adjusted logistic mixed effect models were used to investigate the association between green space and antenatal depression after controlling for confounding variables. Results: Maternal exposure to green space were not associated with lower odds of antenatal depression. Indications of effect modifications due to relevant factors were not observed. Conclusions: This study did not determine an association between access to green space (measured based on the distance to the nearest green space) and antenatal depression. Therefore, a link between green space and antenatal depression was not established. For that reason, ensuring residential areas contain adequate green space may or may not be helpful in preventing antenatal depression and adverse health outcomes associated with this depression. More studies focusing on pregnant women in a range of social contexts, and considering both exposure and access to green space, are warranted to determine the relationships between green space and antenatal depression.

Vaccine Education During Pregnancy and Timeliness of Infant Immunization

OBJECTIVES

Pregnant women routinely receive information in support of or opposing infant immunization. We aimed to describe immunization information sources of future mothers' and determine if receiving immunization information is associated with infant immunization timeliness.

METHODS

We analyzed data from a child cohort born 2009-2010 in New Zealand. Pregnant women (N = 6822) at a median gestation of 39 weeks described sources of information encouraging or discouraging infant immunization. Immunizations received by cohort infants were determined through linkage with the National Immunization Register (n = 6682 of 6853 [98%]). Independent associations of immunization information received with immunization timeliness were described by using adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Immunization information sources were described by 6182 of 6822 (91%) women. Of these, 2416 (39%) received information encouraging immunization, 846 (14%) received discouraging information, and 565 (9%) received both encouraging and discouraging information. Compared with infants of women who received no immunization information (71% immunized on-time), infants of women who received discouraging information only (57% immunized on time, OR = 0.49, 95% CI 0.38-0.64) or encouraging and discouraging information (61% immunized on time, OR = 0.51, 95% CI 0.42-0.63) were at decreased odds of receiving all immunizations on time. Receipt of encouraging information only was not associated with infant immunization timeliness (73% immunized on time, OR = 1.00, 95% CI 0.87-1.15).

CONCLUSIONS

Receipt, during pregnancy, of information against immunization was associated with delayed infant immunization regardless of receipt of information supporting immunization. In contrast, receipt of encouraging information is not associated with infant immunization timeliness.

Housing tenure as a focus for reducing inequalities in the home safety environment: evidence from Growing Up in New Zealand

OBJECTIVES

To determine whether specific demographic characteristics are associated with the presence or absence of household safety strategies.

METHODS

This study was conducted within Growing Up in New Zealand, a contemporary longitudinal study of New Zealand (NZ) children. Multivariable analyses were used to examine the maternal (self-prioritised ethnicity, education, age, self-reported health) and household (area-level deprivation, tenure, crowding, residential mobility, dwelling type) determinants of household safety strategies being present in the homes of young children.

RESULTS

In comparison to family-owned homes, privately owned rental homes were less likely (OR=0.78; 95%CI 0.65-0.92), and government-owned rental homes were more likely (OR=1.74, 95%CI 1.25-2.41) to have eight or more household safety strategies present.

CONCLUSIONS

Living in a privately owned rental home in NZ exposes children to an environment where there are fewer household safety strategies in place. Implications for public health: Housing tenure provides a clear target focus for improving the household safety environment for NZ children.

Green space and pregnancy outcomes: Evidence from Growing Up in New Zealand

OBJECTIVES

To determine whether maternal exposure to green space during pregnancy is associated with birth weight and gestational age, and whether these associations are modified by demographic and residential factors.

METHODS

Data describing 5091 mother-newborn pairs with residential address during pregnancy linked to data describing their green space exposure. Independent associations determined using linear mixed effects models.

RESULTS

Maternal exposure to green space during pregnancy was not associated with birth weight and gestational age for the entire cohort. For pregnant women who have not acquired secondary school education, increased exposure to green space was associated with increased gestational age.

CONCLUSION

The provision of green space might prove to be beneficial in terms of increasing gestational age for pregnant women who have not acquired secondary school education qualifications.

Paternal Depression Symptoms During Pregnancy and After Childbirth Among Participants in the Growing Up in New Zealand Study

IMPORTANCE

Antenatal and postnatal depression are known to be common and associated with poor outcomes for women and their children. There is little evidence on depression symptoms among men during the perinatal period.

OBJECTIVE

To identify characteristics associated with depression symptoms among men whose partners were pregnant and subsequently gave birth.

DESIGN, SETTING, AND PARTICIPANTS

A longitudinal cohort study provided data from a demographically diverse sample of 3523 New Zealand men who completed interviews during their partner's pregnancy and 9 months after the birth of their child. Participants were drawn from a cohort whose partners were pregnant women with a due date between April 25, 2009, and March 25, 2010, who were enrolled in the Growing Up in New Zealand study. Data analysis was conducted from September 1, 2015, to January 8, 2016.

MAIN OUTCOMES AND MEASURES

Depression symptoms were measured using the Edinburgh Postnatal Depression Scale and the 9-item Patient Health Questionnaire; elevated depression symptoms were defined as scores higher than 12 and 9, respectively.

RESULTS

The mean (SD) age of the participants at the antenatal interview was 33.20 (6.25) years (range, 16-63 years). Elevated antenatal paternal depression symptoms affected 82 fathers (2.3%) and were associated with perceived stress (odds ratio [OR], 1.38; 95% CI, 1.30-1.47) and fair to poor health during their partner's pregnancy (OR, 2.06; 95% CI, 1.18-3.61). Elevated postnatal paternal depression symptoms affected 153 (4.3%) of fathers and were associated with perceived stress in pregnancy (OR, 1.12; 95% CI, 1.08-1.17), no longer being in a relationship with the mother 9 months after childbirth (OR, 6.36; 95% CI, 2.28-17.78), having fair to poor health at 9 months (OR, 3.29; 95% CI, 2.10-5.16), being unemployed at 9 months (OR, 1.86; 95% CI, 1.11-3.10), and a history of depression (OR, 2.84; 95% CI, 1.69-4.78).

CONCLUSIONS AND RELEVANCE

Expectant fathers were at risk of depression symptoms if they felt stressed or were in poor health. Rates of elevated depression symptoms were higher during the postpartum period and were associated with adverse social and relationship factors. Identifying fathers most at risk of depressive symptoms and when best to target interventions (antenatal or postnatal) may be beneficial to men and their families.

Infant Behavior Questionnaire-Revised Very Short Form: A New Factor Structure's Associations With Parenting Perceptions and Child Language Outcomes

The Infant Behavior Questionnaire Revised-Very Short Form (IBQ-R VSF; Putnam, Helbig, Gartstein, Rothbart, & Leerkes, 2014 ) is a new publicly available measure of infant temperament measuring positive affectivity/surgency (PAS), negative emotionality (NEG), and orienting and regulatory capacity (ORC). Although the initial psychometric properties of the 3-factor model appear promising, it has not been administered to a large and diverse sample and its predictive validity has not been established. This study administered the IBQ-R VSF to a diverse sample of 5,639 mothers of infants aged between 23 and 52 weeks. Confirmatory factor analysis found that the 3-factor solution did not meet the requirement for satisfactory model fit. Exploratory factor analysis found that a 5-factor solution (PAS, NEG, Orienting Capacity, Affiliation/Regulation, and Fear) was statistically and conceptually the most parsimonious. All 5 temperament dimensions were found to relate to both mother- and partner-reported infant closeness, parenting confidence, and parenting satisfaction, and four of the dimensions (PAS, Orienting Capacity, NEG, and Fear) related to the infants' communication development. Some parental differences were also found. Together these findings suggest that the 5-factor IBQ-R VSF is a promising measure of infant temperament and is related to parenting perceptions and child language development.

A Cross-Cultural Analysis of the Infant Behavior Questionnaire Very Short Form: An Item Response Theory Analysis of Infant Temperament in New Zealand

The Infant Behavior Questionnaire-Revised Very Short Form (IBQ-R VSF; Putnam, Helbig, Gartstein, Rothbart, & Leerkes, 2014 ) is a newly published measure of infant temperament with a 3-factor structure. Recently Peterson et al. ( 2017 ) suggested that a 5-factor structure (Positive Affectivity/Surgency, Negative Emotionality, Orienting Capacity, Affiliation/Regulation, and Fear) was more parsimonious and showed promising reliability and predictive validity in a large, diverse sample. However, little is known about the 5-factor model's precision across the temperament dimensions range and whether it discriminates equally well across ethnicities. A total of 5,567 mothers responded to the IBQ-R VSF in relation to their infants (N = 5,639) between 23 and 52 weeks old. Using item response theory, we conducted a series of 2 parameter logistic item response models and found that 5 IBQ-R VSF temperament dimensions showed a good distribution of estimates across each latent trait range and these estimates centered close to the population mean. The IBQ-R VSF was also similarly precise across 4 ethnic groups (European, Māori, Pacific peoples, and Asians), suggesting that it can be used as comparable measure for infant temperament in a diversity of ethnic groups.

Ethnic disparities in infectious disease hospitalisations in the first year of life in New Zealand

AIM

Infectious disease (ID) hospitalisation rates are increasing in New Zealand (NZ), especially in pre-school children, and Māori and Pacific people. We aimed to identify risk factors for ID hospitalisation in infancy within a birth cohort of NZ children, and to identify differences in risk factors between ethnic groups.

METHODS

We investigated an established cohort of 6846 NZ children, born in 2009-2010, with linkage to a national data set of hospitalisations. We used multivariable logistic regression to obtain odds ratios (OR) for factors associated with ID hospitalisation in the first year of life, firstly for all children, and then separately for Māori or Pacific children.

RESULTS

In the whole cohort, factors associated with ID hospitalisation were Māori (OR: 1.49, 95% CI: 1.17-1.89) or Pacific (2.51; 2.00-3.15) versus European maternal ethnicity, male gender (1.32; 1.13-1.55), low birthweight (1.94, 1.39-2.66), exclusive breastfeeding for <4 months (1.22, 1.04-1.43), maternal experience of health-care racism (1.60, 1.19-2.12), household deprivation (most vs. least deprived quintile of households (1.50, 1.12-2.02)), day-care attendance (1.43, 1.12-1.81) and maternal smoking (1.55, 1.26-1.91). Factors associated with ID hospitalisation for Māori infants were high household deprivation (2.16, 1.06-5.02) and maternal smoking (1.48, 1.02-2.14); and for Pacific infants were delayed immunisation (1.72, 1.23-2.38), maternal experience of health-care racism (2.20, 1.29-3.70) and maternal smoking (1.59, 1.10-2.29).

CONCLUSIONS

Māori and Pacific children in NZ experience a high burden of ID hospitalisation. Some risk factors, for example maternal smoking, are shared, while others are ethnic-specific. Interventions aimed at preventing ID hospitalisations should address both shared and ethnic-specific factors.