Developmental trajectories of conduct problems and time-varying peer problems: the Bergen child study.

BACKGROUND: While it is increasingly acknowledged that conduct problems and peer problems often co-occur in development, less is known about the ways in which peer problems may alter the developmental course of conduct problems for distinct subgroups. METHODS: Using data from a large population-based study in Norway (the Bergen Child Study/youth@hordaland; 47.4% males), we estimated group-based trajectories of conduct problems and the presence of time-varying peer problems on the developmental progression of conduct problems between seven and 19 years of age. Risk factors for group membership were also examined. RESULTS: A 3-group model of conduct problems best fit the data (non-engagers, low-engagers, moderate-stable). The presence of peer problems increased the estimated level of conduct problems for both the low-engagers and moderate-stable groups across adolescence. No differences in conduct problems were observed when peer problems were present in childhood or preadolescence for these two groups, nor for the non-engagers group at any point. Being male, having lower perceived economic wellbeing, and lower levels of parental education predicted group membership for the moderate-stable group, whilst lower paternal education predicted membership for the low-engagers group. CONCLUSIONS: Support for developmental 'turning points' was found, suggesting that adolescence is a particularly salient time for those with conduct problems. In particular, the presence of peer problems can increase observed conduct problems at this stage in development.

An examination of behavioural and emotional problems in children exposed prenatally to the 27F Chilean earthquake: findings from the ELPI cohort.

PURPOSE: Associations between prenatal earthquake exposure and children's mental health remain unclear. Moreover, there is a paucity of research using quasi-experimental statistical techniques to diminish potential selection bias. Thus, this study aimed to explore the impact of prenatal exposure to the Chilean earthquake of 2010 on children's behavioural and emotional problems between 1½ and 3 years old using propensity score matching. METHODS: Participants included 1549 families from the Encuesta Longitudinal de la Primera Infancia cohort in Chile. Maternal reports using the Child Behaviour Checklist (CBCL) were used to assess behavioural and emotional problems between 1½ and 3 years old. Information on prenatal earthquake exposure was collected via maternal report. The Kernel matching estimator was used to compare the average treatment effects of children who were exposed to the earthquake compared to those who were not. RESULTS: Five of the seven CBCL outcomes were statistically significant after matching and adjustment for multiple testing, suggesting greater difficulties for exposed children which included emotional reactivity, anxious/depressed, sleep problems, attention problems, and aggression (mean difference of 0.69, 0.87, 0.73, 0.85, 3.51, respectively). The magnitude of the effect was small to medium. CONCLUSION: Findings contribute to the potential causal inferences between prenatal earthquake exposure and increased behavioural and emotional problems in early childhood. Results suggest that in utero experiences may have long-term consequences for infants' well-being, supporting the need for specific interventions in pregnancy after natural disasters.

Joint Developmental Trajectories of Conduct Problems and Hyperactivity/Inattention: Antecedent Risk Markers for Group Membership.

This study investigated joint trajectories of conduct problems and hyperactivity/inattention from age three to nine in a cohort of 7,507 children in Ireland (50.3% males; 84.9% Irish). The parent-reported Strengths and Difficulties Questionnaire was used to collect information on conduct problems (CP) and hyperactivity/inattention (HI). Information regarding risk markers was collected when participants were nine-months-old via parent report and standardised assessments. Using a person-centred approach (i.e., group-based multi trajectory modelling), six trajectories were identified: no CP/low HI, low-stable CP/HI, low-declining CP/stable HI, desisting co-occurring CP/HI, pure-increasing HI, and high chronic co-occurring CP/HI. Specific risk markers for group membership included: male sex; birth complications; perceived difficult temperament; lower primary caregiver age and education level, and higher stress level; prenatal exposure to smoking, and indicators of lower socioeconomic status. Primary caregiver-child bonding and having siblings were protective markers against membership in elevated groups. Results suggest support for both 'pure' HI and co-occurring trajectories of CP and HI emerging in toddlerhood. However, no support was found for a 'pure' CP trajectory, which may support the suggestion that children on a persistent CP trajectory will have coexisting HI. Intervention efforts may benefit from starting early in life and targeting multiple risk markers in families with fewer resources.

Breastfeeding and externalising problems: a quasi-experimental design with a national cohort.

Evidence from correlational studies supporting the benefits of breastfeeding on children's externalising problems is mixed. Quasi-experimental approaches can help in better understanding possible 'effects'. We aimed to investigate the longitudinal impact of breastfeeding on externalising problems from childhood into adolescence. Participants included ~ 5000 full-term children, from the Growing Up in Ireland Child Cohort. Externalising problems (conduct problems and hyperactivity) were assessed using both the parent and teacher versions of the Strengths and Difficulties Questionnaire when children were age 9 and 13. Maternal reports were used to collect retrospective information on breastfeeding. Propensity score matching, and adjusting for multiple testing were used to compare the average treatment effects for children who were breastfed. Post matching results revealed statistically significant reductions in hyperactivity at age nine, using both maternal and teacher reports (difference score - 0.48, 95% CI - 0.85, - 0.11; and - 0.51, 95% CI - 0.90, - 0.12, respectively), for children who were breastfed between 6 and 12 months, but not thereafter. These effects were not maintained at age 13. Moreover, no effects of breastfeeding on conduct problems were found at any age, regardless of duration, using either maternal or teacher report. While some benefits of breastfeeding were found, compatible with a temporary modest reduction in hyperactivity, related to being breastfed for 26-50 weeks, these results must be viewed in the context of reliance of propensity score matching on observable characteristics. Additionally, our results are suggestive of a potential non-linear dose-response of breastfeeding on hyperactivity.

Maternal warmth and toddler development: support for transactional models in disadvantaged families.

Studies support cognitive and social domains of development as entwined in childhood, however, there is a paucity of investigation into the nature of the mother-child relationship within an interdependence framework. Furthermore, the focus on these processes within families from impoverished communities using frequent assessments in early childhood has been limited. Our objectives were to identify (1) the directional associations between toddler's communication ability and social competence, (2) to establish whether the association between toddler's communication ability and social competence is mediated by maternal warmth, and (3) to establish support for transactional models between toddlers' outcomes and maternal warmth in disadvantaged communities in Ireland. Participants included 173 toddlers and their families enrolled in a prenatally commencing prevention programme. Toddler's communication and social competence were assessed at 12, 18, 24 and 36 months and maternal warmth at 6 and 24 months. Cross-lagged models were estimated examining multiple paths of associations simultaneously. Direct and indirect paths of maternal warmth were also examined. Bi-directional associations were found between communication ability and social competence from 12 to 24 months but not thereafter. Maternal warmth did not significantly mediate these associations, however, support of a transactional model was found with social competence. The results support early positive associations between better communication ability and social competence in the first 2 years, however, they suggest that these associations are no longer present by the third year. The role of maternal warmth in fostering social competencies is important for toddlers and equally important is toddler's level of social competence in eliciting increased maternal warmth.

Trajectories of Mental Health Problems in Childhood and Adult Voting Behaviour: Evidence from the 1970s British Cohort Study.

The link between childhood mental health difficulties such as conduct problems and adult political abstention has been overlooked despite early mental health difficulties potentially resulting in political self-marginalisation. Using the1970s British Cohort Study, we estimate developmental trajectories of conduct problems (i.e., from 5 to 16 years). Logistic regression, linear probability models, and propensity score matching were then conducted to test the association between trajectory group membership and voter turnout at 30, 42, and 46 years of age. Three distinct trajectories of conduct problems were identified: a normative (n = 11,871; reference group), moderate-chronic (n = 3433), and elevated-chronic (n = 250) group. Results revealed an association between conduct problems and decreased turnout. In particular the elevated-chronic group had a decreased odds of voting of 52.2%, 52.0%, and 45.7%, as compared to the normative group at 30, 42, and 46 years respectively. The moderate-chronic group had a decreased odds of voting of 24.7% as compared to the normative group at age 30 only. Matched results and linear probability models substantiated findings, suggesting (1) the importance of considering childhood factors when examining antecedents of lifelong voting behaviour, and (2) the political self-marginalisation of people with chronic childhood conduct problems more than 3 decades later. Supplementary Information: The online version contains supplementary material available at 10.1007/s11109-022-09852-9.

Multi-Trajectories of Conduct Problems, Hyperactivity/Inattention, and Peer Problems Across Childhood: Results from the Growing Up in Scotland Birth Cohort.

Using a person-centred approach, this study inspected multi-trajectories of conduct problems, hyperactivity/inattention and peer problems, and associated risk factors for group membership. The sample included 3,578 children (50.8% males) from a population birth cohort in Scotland (Growing Up in Scotland). The parental version of the Strengths and Difficulties Questionnaire (SDQ) was used when children were 4, 5, 6, 7, and 10 years old. Antecedent factors at the perinatal, child, and family levels were collected using parental reports, observation, and standardised assessments at 10, 24, and 36 months. A group-based multi-trajectory analysis was employed. Findings showed that a six-group model best fit the data. Identified groups included non-engagers, normative, decreasing externalising/low peer problems, low externalising/moderate peer problems, moderate externalising/increasing peer problems and multimorbid moderate-high chronic. Findings suggest multimorbidity between externalising behaviours and peer problems in the more elevated groups. Two common protective factors emerged across all groups: caregiver mental health and parent-infant attachment. Identified risk factors were specific to group membership. Risk factors for the most elevated group included single-parent status, social deprivation, previous neonatal intensive care unit admission, child sex, whilst children's expressive language was a protective factor. Taken together, findings contribute to the emerging literature modelling trajectories of externalising behaviours and peer problems simultaneously and have important practical implications for prevention of problems in childhood, by identifying targets at the perinatal, child, and family levels.

The association of different presentations of maternal depression with children's socio-emotional development: A systematic review.

Maternal depression from the perinatal period onwards is a global health priority associated with an increased likelihood of suboptimal socio-developmental outcomes in offspring. An important aspect of this association is the extent to which sustained maternal depression impacts on these outcomes. The current review synthesised the evidence on maternal depression from the perinatal period onwards and offspring internalising, externalising, and social competence outcomes. We also identified sources of methodological bias. A systematic review following PRISMA guidelines was conducted. Longitudinal studies targeting biological mothers with depressive symptomology, detailing onset, using repeated validated measures, and assessing children's outcomes between three and 12 years were included. Twenty-four studies met inclusion criteria. Findings supported the validity of different presentations of maternal depression, including consistent identification of a group of chronically depressed mothers across countries. Mothers within this group reported poorer internalising, externalising, and social competence outcomes for their offspring, with the highest levels of child problems associated with greater maternal chronicity and symptom severity. Results differed by measurement type with mothers rating poorer outcomes in comparison to teachers reports. For timing of depression, evidence was inconsistent for independent effects of antenatal or postnatal depression on child outcomes. There was substantial variability in study quality assessment. Assessing different presentations of maternal depression is essential for capturing the longitudinal associations between maternal depression and offspring outcomes to inform targets of early intervention. Chronicity, severity, and concurrent maternal depression have important implications for children's development and should be targeted in future programme planning. Further research in low- and middle-income countries is warranted.

Income and gambling disorder: A longitudinal matched case-control study with registry data from Norway.

Background: Untangling the association between gambling disorder (GD) and income is complex. Financial strain is often a consequence of GD. At the same time GD is more prevalent in the context of poverty, suggesting income may be a risk marker for GD. Aims: The aim of the present study was to investigate whether income is a risk marker for GD and whether the longitudinal average predicted income for patients with GD between 2008 and 2018 compared to control groups. The study also explored the potential heterogeneity in income trajectories for patients with GD and associated characteristics. Methods: A matched case-control longitudinal study was conducted using two Norwegian registries (i.e., the Norwegian Patient Registry and the Division of Welfare Statistics). A total of 65,771 participants were included, 5131 who were diagnosed with GD (cases), 30,467 diagnosed with any other psychiatric or somatic disorder (control), and 30,164 from the general population (control). Multinomial and ordinary least squares regressions, along with group-based trajectory models were estimated. Results: Individuals with GD were more likely to have income levels in the bottom quartile of the nationally reported average income in 2008 compared to the general population. However, this was not observed in the psychiatric/somatic group. Both GD and psychiatric/somatic groups were less likely to have average/above average income compared to the general population. Expected income for patients with GD was below national averages between 2008 and 2018, with significant group differences identified. Estimated trajectories for patients with GD resulted in a seven-group model. Males were more likely to have membership in higher income groups, whereas females and younger GD patients were more likely to belong to trajectory groups with the lowest income. Conclusion: The results suggest income is a risk marker for GD. Heterogeneity present across the income distribution for patients with GD, coupled with identifiable patient characteristics, may help in prediction and screening of GD.

Temporal order of diagnosis between gambling disorder and substance use disorders: Longitudinal results from the Norwegian Patient Registry.

Introduction: Previous research has established co-occurrence between substance use disorders (SUDs) and gambling disorder (GD). Less well understood is the temporal sequencing of onset between these disorders, and in particular whether SUD is a risk factor for GD. The present study examined the temporal order between registered diagnoses of SUD and GD, stratified by sex. Methods: A study with a longitudinal design using objective registry data drawn from the Norwegian Patient Registry was carried out. Among the patients with a registered diagnosis of GD between 2008 and 2018 (N = 5,131; males = 81.8%), those (who in addition) had a registered diagnosis of any SUD (n = 1,196; males = 82.1%) were included. The measures included a registered diagnosis using the ICD-10 of both GD (code F63.0) and SUDs (codes F10-F19) by a health care professional. Binomial tests were used to identify the temporal order between SUD(s) and GD. Co-occurring cases (i.e., cases diagnosed within the same month) were removed in the main analyses. Results: Results showed a significant directional path from SUD to GD but no support for the reversed path (i.e., from GD to SUD). This finding was similar overall for (i) both males and females, (ii) when different SUDs (alcohol, cannabis, sedatives, and polysubstance) were examined individually, and (iii) when specifying a 12-month time-lag between diagnoses. Conclusions: The findings suggest that experiencing SUD(s) is a risk marker for GD given the temporal precedence observed for patients in specialised healthcare services seeking treatment. These results should be considered alongside screening and prevention efforts for GD.

An empirical study on attitudes toward gambling when sportswashing is involved.

Sportswashing is defined as individuals, groups, companies, or countries/regimes' involvement in sports to improve their own reputation and/or to distract from or normalize wrongdoing. This cross-sectional survey is the first empirical study on sportswashing in relation to gambling. The sample consisted of United Kingdom residents who reported past 12-month gambling (N = 786, 50% women, mean age = 45.6, SD = 15.2). We investigated how many were familiar with sportswashing and their attitudes toward gambling when sportswashing is involved. Exploratory and confirmatory factor analysis (CFA) were conducted on the attitudes scale that was developed for the current study. Multiple regressions were used to examine if individual differences in terms of age, gender, personality, moral foundations, political trust and efficacy, and/or gambling risk were associated with such attitudes. Finally, we examined the percentage of people who avoid gambling on teams/events when sportswashing is involved, including group differences in avoidance and motivations for avoidance according to gambling risk. The results showed that only 32% had heard about sportswashing prior to the survey. CFA indicated that attitudes toward sportswashing and gambling as conceptualized in the scale used in the current study can broadly be categorized into two dimensions: How individuals relate to sportswashing when gambling ("self-factor") and how individuals think gambling companies and regulators should regulate sportswashing and gambling [an "external-factor," p < 0.001, CFI = 0.0.996, RMSEA = 0.090, 90% CI (0.077, 0.104)]. Multiple regressions indicated that measures of individual differences explained a significant amount of variance in self-oriented (F (17, 765) = 7.19, p < 0.001, adjusted R2 = 0.12) and external-oriented (F (17, 765) = 8.40, p < 0.001. adjusted R2 = 0.14) attitude toward gambling and sportswashing. Avoidance of betting when sportswashing is involved was reported by 43%. The proportion was lower among those with moderate gambling risk/problem gambling (35%) compared to those with no/low gambling risk (45%). It is concluded that further scale development could help elucidate individual differences in attitudes toward sportswashing and gambling. Sportswashing remains an important social issue, and the present study indicates that this has high relevance for the gambling field.

Concomitant Trajectories of Internalising, Externalising, and Peer Problems Across Childhood: a Person-centered Approach.

This study investigated trajectories of concomitant internalising, externalising, and peer problems, and associated risk factors for group-membership, using a person-centered approach to better understand heterogeneity in subgroups identified. A cohort of 7,507 children in Ireland was followed from infancy to late childhood (50.3%, males; 84.9% Irish). The parent-version of the Strengths and Difficulties Questionnaire was used when children were 3, 5, 7 and 9 years of age. Information on antecedent risk factors was collected when children were 9 months. Group-based multi-trajectory modelling and multinomial logistic regression were used. Six subgroups of children with distinct profiles were identified, evidencing both homotypic and heterotypic comorbidity. No support of a 'pure' internalising, externalising or peer problems group was found in any identified trajectory group. Difficulties in one problem domain indicated the presence of difficulty in another problem domain for all children in elevated groups. Risk factors associated with group-membership were complex, with only three common factors across elevated groups: prenatal exposure to smoking, maternal education, and maternal stress. Specific risk factors for group-membership included low birth weight, sex, maternal age, maternal depression, family composition, social class, medical card status and quality of attachment. Despite some overlap in predictors, the combination of predictors specific to each group would suggest tailored programming. For children with the most acute problems, programming targets should include families with boys, born with low birth weight, exposed to smoking prenatally, with mothers who have lower levels of education, postnatal depression, increased stress and fewer financial resources.

Breastfeeding initiation and duration in Chile: understanding the social and health determinants.

BACKGROUND: Given the support for the numerous benefits of breastfeeding, a better understanding of social and health determinants is necessary, particularly in under-researched populations. We examined determinants of breastfeeding initiation and duration using a national cohort of Chilean mothers. METHODS: Participants included 13 738 families enrolled in the Encuesta Longitudinal de la Primera Infancia cohort. Data were collected in 2010 and 2012. Families from all regions of the country were considered. Breastfeeding information was collected via maternal report and standardised assessments were used to collect information on maternal IQ and personality. Logistic and linear regressions were used to identify predictors of breastfeeding initiation and duration. RESULTS: Breastfeeding was initiated by 95.2% of mothers. Variation in duration of breastfeeding was large, ranging from 1 to 48 months (M = 11.74; SD = 8.74). Maternal IQ, low-risk prenatal behaviours, conditions at birth and the presence of a partner were relevant predictors of both initiation and duration of breastfeeding, whereas personality and contextual/socioeconomic factors were relevant only for breastfeeding duration. Differences between regions were observed. Rates of caesarean deliveries are alarmingly high and triple that of the global WHO recommendations, at 45% of deliveries in Chile, which are implicated in both initiation and duration. CONCLUSIONS: Breastfeeding rates exceed Chilean target goals although vary by region. Global targets now need to be focused on. Social and health determinants are implicated in both initiation and duration of breastfeeding. These findings suggest important targets for policy development and breastfeeding initiatives in Chile, particularly concerning the reduction of surgical deliveries.

Breastfeeding and behavioural problems: Propensity score matching with a national cohort of infants in Chile.

IMPORTANCE: Potential effects of breast feeding on children's behaviour remains an elusive debate given inherent methodological challenges. Propensity score matching affords benefits by ensuring greater equivalence on observable social and health determinants, helping to reduce bias between groups. OBJECTIVES: We examined whether the duration of breast feeding had an impact on children's externalising and internalising behaviours. STUDY DESIGN: A cohort study (Encuesta Longitudinal de la Primera Infancia cohort) that included 3037 Chilean families who were enrolled in 2010. Follow-up data was collected in 2012. SETTING: General community. PARTICIPANTS: Population-based sample. Eligibility criteria: children born full-term with complete data on matching variables. Matching variables included: healthcare system as a proxy of income, presence of a partner/spouse in the household, maternal age, educational level, IQ, working status, type of work, diagnosis of prenatal depression by a healthcare professional, smoking during pregnancy, delivery type, child sex, weight at birth, incubation following delivery, and child age. EXPOSURE: Duration of breast feeding. MAIN OUTCOMES AND MEASURES: Externalising and internalising problems assessed using the Child Behaviour Checklist. RESULTS: Matched results revealed benefits of any breast feeding, up to 6 months, on emotional reactivity and somatic complaints (mean difference of -1.00, 95% CI, -1.84 to -0.16 and -1.02, 95% CI, -1.76 to -0.28, respectively). Children breast fed between 7 and 12 months also had reduced scores on emotional reactivity, in addition to attention problems (mean difference of -0.86, 95% CI, -1.66 to -0.06 and -0.50, 95% CI, -0.93 to -0.07, respectively). No benefits were observed for children breast fed 13 months or more. CONCLUSION: Reduced internalising difficulties and inattention were found in children breast fed up to a year, suggesting that breast feeding may have beneficial impacts on these areas of development. The magnitude of effect was modest. Extended durations of breast feeding did not appear to offer any benefits.

Predicting postpartum depression among adolescent mothers: A systematic review of risk.

BACKGROUND/AIMS: Postpartum depression (PPD) is a debilitating illness with negative consequences for affected mothers and their children (e.g., poor maternal-infant attachment, deficits in children's social, emotional, and cognitive development). While it is suggested that adolescent mothers are at increased risk of PPD, there is a paucity of research exploring factors that place adolescent mothers at risk. This systematic review aims to identify risk factors associated with adolescent PPD and appraise the quality of this evidence-base. METHOD: A systematic review was conducted in May of 2018, using PsycINFO, EMBASE, MEDLINE, ASSIA, CINAHL, MIDIRS, and ProQuest Dissertations and Theses Global database, following PRISMA guidelines. Inclusion criteria included studies from developed countries; published after 1992; using a validated measure of PPD; with onset of illness within 12 months of childbirth, but which had persisted past two-weeks postpartum; adolescent mothers < 20 years of age; and risk factor(s) that occurred prior to birth. RESULTS: Fourteen studies were included, ranging from weak-to-strong in quality. Results suggest several risk factors implicated in the onset of adolescent PPD, including prior depression, lack of familial social support, and socio-economic hardship. CONCLUSIONS/LIMITATIONS: Awareness of risk factors for healthcare professionals working with pregnant adolescents is of high importance to better facilitate early identification and to provide support for adolescents at risk. Future research ought to consider employing prospective longitudinal designs, along with clearly defined, timely and validated measurements of risk factors and PPD. Limitations include only studies published in English and low agreement on the included studies selection bias.

Development of Aggression Subtypes from Childhood to Adolescence: a Group-Based Multi-Trajectory Modelling Perspective.

The persistence of elevated subtypes of aggression beginning in childhood have been associated with long-term maladaptive outcomes. Yet it remains unclear to what extent there are clusters of individuals following similar developmental trajectories across forms (i.e., physical and indirect) and functions (i.e., proactive and reactive) of aggression. We aimed to identify groups of children with distinct profiles of the joint development of forms and functions of aggression and to identify risk factors for group membership. A sample of 787 children was followed from birth to adolescence. Parent and teacher reports, and standardised assessments were used to measure two forms and two functions of aggressive behaviour, between six and 13 years of age along with preceding child, maternal, and family-level risk-factors. Analyses were conducted using a group-based multi-trajectory modelling approach. Five trajectory groups emerged: non-aggressors, low-stable, moderate-engagers, high-desisting, and high-chronic. Coercive parenting increased membership risk in the moderate-engagers and high-chronic groups. Lower maternal IQ increased membership risk in both high-desisting and high-chronic groups, whereas maternal depression increased membership risk in the high-desisting group only. Never being breastfed increased membership risk in the moderate-engagers group. Boys were at greater risk for belonging to groups displaying elevated aggression. Individuals with chronic aggression problems use all subtypes of aggression. Risk factors suggest that prevention programs should start early in life and target mothers with lower IQ. Strategies to deal with maternal depression and enhance positive parenting while replacing coercive parenting tactics should be highlighted in programming efforts.

Counselling interventions to enable women to initiate and continue breastfeeding: a systematic review and meta-analysis.

Background: Many infants worldwide are not breastfeeding according to WHO recommendations and this impacts on the health of women and children. Increasing breastfeeding is identified as a priority area supported by current policy targets. However, interventions are complex and multi-component and it is unclear which elements of interventions are most effective to increase breastfeeding in which settings. Breastfeeding counselling is often part of complex interventions but evidence is lacking on the specific effect of counselling interventions on breastfeeding practices. The aim of this systematic review is to examine evidence on effectiveness of breastfeeding counselling to inform global guidelines. Methods: A systematic search was conducted of six electronic databases in January 2018. Randomised controlled trials comparing breastfeeding counselling with no breastfeeding counselling or different formulations of counselling were included if they measured breastfeeding practices between birth and 24 months after birth. Results: From the 5180 records identified in searches and a further 11 records found by hand searching, 63 studies were included. Of these, 48 were individually-randomised trials and 15 were cluster-randomised trials. A total of 69 relevant comparisons were reported involving 33,073 women. There was a significant effect of counselling interventions on any breastfeeding at 4 to 6 weeks (Relative risk [RR] 0.85, 95% CI 0.77, 0.94) and 6 months (RR 0.92, 95% CI 0.87, 0.94). Greater effects were found on exclusive breastfeeding at 4 to 6 weeks (RR 0.79, 95% CI 0.72, 0.87) and 6 months (RR 0.84, 95% CI 0.78, 0.91). Counselling delivered at least four times postnatally is more effective than counselling delivered antenatally only and/or fewer than four times. Evidence was mostly of low quality due to high or unclear risk of bias of the included trials and high heterogeneity. Conclusions: Breastfeeding counselling is an effective public health intervention to increase rates of any and exclusive breastfeeding. Breastfeeding counselling should be provided face-to-face, and in addition, may be provided by telephone, both antenatally and postnatally, to all pregnant women and mothers with young children. To inform scale-up globally there is a need to further understand the elements of breastfeeding interventions such as counselling and their effectiveness in different contexts and circumstances. Study registration: This systematic review was registered in Prospero (CRD42018086494).

Breastfeeding, Cognitive and Noncognitive Development in Early Childhood: A Population Study.

BACKGROUND AND OBJECTIVES: There is mixed evidence from correlational studies that breastfeeding impacts children's development. Propensity score matching with large samples can be an effective tool to remove potential bias from observed confounders in correlational studies. The aim of this study was to investigate the impact of breastfeeding on children's cognitive and noncognitive development at 3 and 5 years of age. METHODS: Participants included ∼8000 families from the Growing Up in Ireland longitudinal infant cohort, who were identified from the Child Benefit Register and randomly selected to participate. Parent and teacher reports and standardized assessments were used to collect information on children's problem behaviors, expressive vocabulary, and cognitive abilities at age 3 and 5 years. Breastfeeding information was collected via maternal report. Propensity score matching was used to compare the average treatment effects on those who were breastfed. RESULTS: Before matching, breastfeeding was associated with better development on almost every outcome. After matching and adjustment for multiple testing, only 1 of the 13 outcomes remained statistically significant: children's hyperactivity (difference score, -0.84; 95% confidence interval, -1.33 to -0.35) at age 3 years for children who were breastfed for at least 6 months. No statistically significant differences were observed postmatching on any outcome at age 5 years. CONCLUSIONS: Although 1 positive benefit of breastfeeding was found by using propensity score matching, the effect size was modest in practical terms. No support was found for statistically significant gains at age 5 years, suggesting that the earlier observed benefit from breastfeeding may not be maintained once children enter school.

Developmental Associations Between Conduct Problems and Expressive Language in Early Childhood: A Population-Based Study.

Conduct problems have been associated with poor language development, however the direction of this association in early childhood remains unclear. This study examined the longitudinal directional associations between conduct problems and expressive language ability. Children enrolled in the UK Millennium Cohort Study (N = 14, 004; 50.3 % boys) were assessed at 3 and 5 years of age. Parent reports of conduct problems and standardised assessments of expressive language were analyzed using cross-lagged modeling. Conduct problems at 3 years was associated with poorer expressive language at 5 years and poorer expressive language at 3 years was associated with increased conduct problems by 5 years. The results support reciprocal associations, rather than a specific unidirectional path, which is commonly found with samples of older children. The emergence of problems in either domain can thus negatively impact upon the other over time, albeit the effects were modest. Studies examining the effects of intervention targeting conduct problems and language acquisition prior to school entry may be warranted in testing the efficacy of prevention programmes related to conduct problems and poor language ability early in childhood.

Factors Associated with Breastfeeding Initiation: A Comparison between France and French-Speaking Canada.

BACKGROUND: Breastfeeding is associated with multiple domains of health for both mothers and children. Nevertheless, breastfeeding initiation is low within certain developed countries. Furthermore, comparative studies of initiation rates using harmonised data across multiple regions is scarce. OBJECTIVE: The aim of the present study was to investigate and compare individual-level determinants of breastfeeding initiation using two French-speaking cohorts. METHODS: Participants included ~ 3,900 mothers enrolled in two cohort studies in Canada and France. Interviews, questionnaires, and medical records were utilised to collect information on maternal, family, and medical factors associated with breastfeeding initiation. RESULTS: Rates of breastfeeding initiation were similar across cohorts, slightly above 70%. Women in both Canada and France who had higher levels of maternal education, were born outside of their respective countries and who did not smoke during pregnancy were more likely to initiate breastfeeding with the cohort infant. Notably, cohort effects of maternal education at the university level were found, whereby having 'some university' was not statistically significant for mothers in France. Further, younger mothers in Canada, who delivered by caesarean section and who had previous children, had reduced odds of breastfeeding initiation. These results were not found for mothers in France. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: While some similar determinants were observed, programming efforts to increase breastfeeding initiation should be tailored to the characteristics of specific geographical regions which may be heavily impacted by the social, cultural and political climate of the region, in addition to individual and family level factors.