Aggressive behaviour in childhood and adolescence: the role of smoking during pregnancy, evidence from four twin cohorts in the EU-ACTION consortium

Large-Scale Data Harmonization Across Prospective Studies

The Preconception Period Analysis of Risks and Exposures Influencing Health and Development (PrePARED) Consortium creates a novel resource for addressing preconception health by merging data from numerous cohort studies. In this paper, we describe our data harmonization methods and results. Individual-level data from 12 prospective studies were pooled. The crosswalk-cataloging-harmonization procedure was used. The index pregnancy was defined as the first postbaseline pregnancy lasting more than 20 weeks. We assessed heterogeneity across studies by comparing preconception characteristics in different types of studies. The pooled data set included 114,762 women, and 25,531 (22%) reported at least 1 pregnancy of more than 20 weeks' gestation during the study period. Babies from the index pregnancies were delivered between 1976 and 2021 (median, 2008), at a mean maternal age of 29.7 (standard deviation, 4.6) years. Before the index pregnancy, 60% of women were nulligravid, 58% had a college degree or more, and 37% were overweight or obese. Other harmonized variables included race/ethnicity, household income, substance use, chronic conditions, and perinatal outcomes. Participants from pregnancy-planning studies had more education and were healthier. The prevalence of preexisting medical conditions did not vary substantially based on whether studies relied on self-reported data. Use of harmonized data presents opportunities to study uncommon preconception risk factors and pregnancy-related events. This harmonization effort laid the groundwork for future analyses and additional data harmonization.

A meta-analysis of genetic effects associated with neurodevelopmental disorders and co-occurring conditions

A systematic understanding of the aetiology of neurodevelopmental disorders (NDDs) and their co-occurrence with other conditions during childhood and adolescence remains incomplete. In the current meta-analysis, we synthesized the literature on (1) the contribution of genetic and environmental factors to NDDs, (2) the genetic and environmental overlap between different NDDs, and (3) the co-occurrence between NDDs and disruptive, impulse control and conduct disorders (DICCs). Searches were conducted across three platforms: Web of Science, Ovid Medline and Ovid Embase. Studies were included only if 75% or more of the sample consisted of children and/or adolescents and the studies had measured the aetiology of NDDs and DICCs using single-generation family designs or genomic methods. Studies that had selected participants on the basis of unrelated diagnoses or injuries were excluded. We performed multilevel, random-effects meta-analyses on 296 independent studies, including over four million (partly overlapping) individuals. We further explored developmental trajectories and the moderating roles of gender, measurement, geography and ancestry. We found all NDDs to be substantially heritable (family-based heritability, 0.66 (s.e. = 0.03); SNP heritability, 0.19 (s.e. = 0.03)). Meta-analytic genetic correlations between NDDs were moderate (grand family-based genetic correlation, 0.36 (s.e. = 0.12); grand SNP-based genetic correlation, 0.39 (s.e. = 0.19)) but differed substantially between pairs of disorders. The genetic overlap between NDDs and DICCs was strong (grand family-based genetic correlation, 0.62 (s.e. = 0.20)). While our work provides evidence to inform and potentially guide clinical and educational diagnostic procedures and practice, it also highlights the imbalance in the research effort that has characterized developmental genetics research.

Tobacco use during pregnancy

The use of tobacco during pregnancy is the leading preventable cause of pregnancy complications and adverse birth outcomes. In high-income countries, around one in 10 pregnant women smokes tobacco, while smokeless tobacco is the primary form of tobacco used in many low- and middle-income countries. Although the risk of tobacco-related harms can be reduced substantially if mothers cease smoking in the first trimester of pregnancy, the proportion of women who successfully quit smoking during pregnancy remains modest. Psychosocial interventions are first-line treatment, with some high-quality evidence showing that counselling is effective in promoting smoking cessation among pregnant women. There is insufficient evidence regarding the efficacy and safety of smoking cessation pharmacotherapies when used during pregnancy, although in some countries nicotine replacement therapy is recommended for pregnant women who have been unable to quit without pharmacological assistance. E-cigarettes are increasingly being used as a smoking cessation aid in the general population of smokers, but more research is needed to determine if e-cigarettes are a safe and effective treatment option for pregnant women.

What predicts the knowledge of breastfeeding practices among late adolescent girls? evidence from a cross-sectional analysis

INTRODUCTION

Breastfeeding is one of the most effective ways to ensure infant health and survival. Inadequate breastfeeding practices, and knowledge among adolescent mothers have led to unprecedented infant and child morbidity and mortality. Given, the high global prevalence of adolescent mothers it is imperative to understand how the knowledge of breastfeeding practices operates among adolescent girls across different socio-economic settings.

MATERIALS & METHODS

Data was carried out from Understanding the Lives of Adolescents and Young Adults (UDAYA) survey, conducted in 2015-16. Descriptive statistics along with bivariate analysis was done to examine the preliminary results. For analysing the association between the binary outcome variable and other explanatory variables, binary logistic regression method was used. The explanatory variables were educational status of the respondent, media exposure, working status, ever pregnant status (only for married adolescent girls), sex and age of the household head, educational status of the head of the household, caste, religion, wealth index, residence and states.

RESULTS

About 42%, 50%, and 42% of married adolescent girls had knowledge of immediate breastfeeding, yellowish milk, and exclusive breastfeeding respectively. The odds of knowledge about immediate breastfeeding [married-AOR: 1.57; CI: 1.09-2.28 and unmarried-AOR: 1.30; CI: 1.08-1.55], yellowish milk feeding [married-AOR: 2.09; CI: 1.46-3.01 and unmarried-AOR: 1.39; CI: 1.17-1.66], and exclusive breastfeeding [married-AOR: 1.74; CI: 1.2-2.52 and unmarried-AOR: 1.46; CI: 1.22-1.76] were significantly more among adolescent girls aged 19 years old compared to 15 years old girls. Adolescent married and unmarried girls with 10 & above years of schooling were 1.82 times [AOR: 1.82; CI: 1.52-2.18] and 2.69 times [AOR: 2.69; CI: 2.08-3.47] more likely to have knowledge about immediate breastfeeding, 1.74 times [AOR: 1.74; CI: 1.45-2.09] and 2.10 times [AOR: 2.10; CI: 1.68-2.62] more likely to have knowledge about yellowish milk feeding, and 3.13 times [AOR: 3.13; CI: 2.6-3.78] and 3.87 times [AOR: 3.87; CI: 2.95-5.08] more likely to have knowledge about exclusive breastfeeding respectively than girls with no schooling.

CONCLUSION

Breastfeeding practices and interpersonal counselling from elders in the household should be encouraged. Ongoing breastfeeding promotion programs of the government should promote high education of adolescent girls. Mass media interventions should be encouraged.

DNA methylome perturbations: an epigenetic basis for the emergingly heritable neurodevelopmental abnormalities associated with maternal smoking and maternal nicotine exposure†

Maternal smoking during pregnancy is associated with an ensemble of neurodevelopmental consequences in children and therefore constitutes a pressing public health concern. Adding to this burden, contemporary epidemiological and especially animal model research suggests that grandmaternal smoking is similarly associated with neurodevelopmental abnormalities in grandchildren, indicative of intergenerational transmission of the neurodevelopmental impacts of maternal smoking. Probing the mechanistic bases of neurodevelopmental anomalies in the children of maternal smokers and the intergenerational transmission thereof, emerging research intimates that epigenetic changes, namely DNA methylome perturbations, are key factors. Altogether, these findings warrant future research to fully elucidate the etiology of neurodevelopmental impairments in the children and grandchildren of maternal smokers and underscore the clear potential thereof to benefit public health by informing the development and implementation of preventative measures, prophylactics, and treatments. To this end, the present review aims to encapsulate the burgeoning evidence linking maternal smoking to intergenerational epigenetic inheritance of neurodevelopmental abnormalities, to identify the strengths and weaknesses thereof, and to highlight areas of emphasis for future human and animal model research therein.

Maternal smoking during pregnancy and risks to depression and anxiety in offspring: An observational study and genome-wide gene-environment interaction analysis in UK biobank cohort

BACKGROUND

Maternal smoking during pregnancy (MSDP) has been reported to be associated with increased anxiety and depression behaviors in offspring. However, there is still scant evidence to support the link between MSDP and anxiety/depression.

METHODS

Using the subjects from the UK Biobank cohort (n = 371,903-432,881). Logistic regression analyses were first conducted to test the correlation between MSDP and anxiety/depression in offspring. Second, genome-wide gene-environment interaction study (GWGEIS) analyses were conducted by PLINK, using MSDP as environmental factor. Genetic correlation analysis of anxiety/depression and smoking was conducted by the LDSC software using the published genome-wide association study (GWAS) summary data of four smoking traits (n = 337,334-1,232,091), anxiety (n = 31,880) and depression (n = 490,359). Finally, pathway enrichment analysis was carried out to detect the pathway involved in the development of offspring anxiety caused by the interaction of MSDP × SNPs.

RESULTS

Observational analyses showed that anxiety and depression status in offspring were significantly associated with MSDP (all p < 0.0001). Further GWEGI analyses observed significant MSDP-gene interaction effects at UNC80 gene for anxiety (p = 9.09 × 10^-9). LDSC did not detect significant genetic correlation between anxiety and smoking traits. Pathway analysis identified 19 significant pathways for anxiety, such as MANALO_HYPOXIA_UP (FDR = 5.50 × 10^-4), REACTOME_ADHERENS_JUNCTIONS_INTERACTIONS (FDR = 0.0304) and ONDER_CDH1_TARGETS_2_UP (FDR = 0.0371).

CONCLUSION

Our study results suggested the important impact of MDSP on the risk of anxiety in offspring, partly attributing to environment-gene interactions effects.

DNA methylation signatures of aggression and closely related constructs: A meta-analysis of epigenome-wide studies across the lifespan

DNA methylation profiles of aggressive behavior may capture lifetime cumulative effects of genetic, stochastic, and environmental influences associated with aggression. Here, we report the first large meta-analysis of epigenome-wide association studies (EWAS) of aggressive behavior (N = 15,324 participants). In peripheral blood samples of 14,434 participants from 18 cohorts with mean ages ranging from 7 to 68 years, 13 methylation sites were significantly associated with aggression (alpha = 1.2 × 10-7; Bonferroni correction). In cord blood samples of 2425 children from five cohorts with aggression assessed at mean ages ranging from 4 to 7 years, 83% of these sites showed the same direction of association with childhood aggression (r = 0.74, p = 0.006) but no epigenome-wide significant sites were found. Top-sites (48 at a false discovery rate of 5% in the peripheral blood meta-analysis or in a combined meta-analysis of peripheral blood and cord blood) have been associated with chemical exposures, smoking, cognition, metabolic traits, and genetic variation (mQTLs). Three genes whose expression levels were associated with top-sites were previously linked to schizophrenia and general risk tolerance. At six CpGs, DNA methylation variation in blood mirrors variation in the brain. On average 44% (range = 3-82%) of the aggression-methylation association was explained by current and former smoking and BMI. These findings point at loci that are sensitive to chemical exposures with potential implications for neuronal functions. We hope these results to be a starting point for studies leading to applications as peripheral biomarkers and to reveal causal relationships with aggression and related traits.

The Effects of an Infant Formula Enriched with Milk Fat Globule Membrane, Long-Chain Polyunsaturated Fatty Acids and Synbiotics on Child Behavior up to 2.5 Years Old: The COGNIS Study

Although early life nutrition influences brain development and mental health, the long-term effects of supplemented infant formula on children´s behavior remain unclear. We analyzed the effects of a bioactive nutrients-enriched-infant formula on children’s behavior up to 2.5 years, compared to a standard infant formula or breastfeeding. Current analysis involved 70 children who were fed a standard infant formula (SF, n = 29) or a bioactive compounds enriched-infant formula (EF, n = 41), during their first 18 months of life, and 33 breastfed (BF) children (reference group) participating in the COGNIS study. Behavioral problems were evaluated using the Child Behavior Checklist at 18 months and 2.5 years. Different statistical analyses were performed using SPSS. EF children aged 2.5 years presented fewer pathological affective problems than SF children. Besides, SF children were classified more frequently as bordering on internalizing problems than BF children. Rates of externalizing problems were increased in SF infants compared to EF and BF infants. Higher maternal IQ was found to have beneficial effects on internalizing and total problem rate in their offspring at 18 months of life; finally, higher maternal educational level was related with fewer ADHD problems in children at 18 months, as well as internalizing, externalizing, total and anxiety problems in children aged 2.5 years. Our analysis suggests that enriched infant formula fed infants seem to show fewer behavioral problems up to 2.5 years compared to a standard infant formula-fed infants. In addition to type of early feeding, maternal IQ and educational level seem to play a key role on children behavioral development.

Content, diagnostic, correlational, and genetic similarities between common measures of childhood aggressive behaviors and related psychiatric traits

BACKGROUND

Given the role of childhood aggressive behavior (AGG) in everyday child development, precise and accurate measurement is critical in clinical practice and research. This study aims to quantify agreement among widely used measures of childhood AGG regarding item content, clinical concordance, correlation, and underlying genetic construct.

METHODS

We analyzed data from 1254 Dutch twin pairs (age 8-10 years, 51.1% boys) from a general population sample for whom both parents completed the A-TAC, CBCL, and SDQ at the same occasion.

RESULTS

There was substantial variation in item content among AGG measures, ranging from .00 (i.e., mutually exclusive) to .50 (moderate agreement). Clinical concordance (i.e., do the same children score above a clinical threshold among AGG measures) was very weak to moderate with estimates ranging between .01 and .43 for mother-reports and between .12 and .42 for father-reports. Correlations among scales were weak to strong, ranging from .32 to .70 for mother-reports and from .32 to .64 for father-reports. We found weak to very strong genetic correlations among the measures, with estimates between .65 and .84 for mother-reports and between .30 and .87 for father-reports.

CONCLUSIONS

Our results demonstrated that degree of agreement between measures of AGG depends on the type (i.e., item content, clinical concordance, correlation, genetic correlation) of agreement considered. Because agreement was higher for correlations compared to clinical concordance (i.e., above or below a clinical cutoff), we propose the use of continuous scores to assess AGG, especially for combining data with different measures. Although item content can be different and agreement among observed measures may not be high, the genetic correlations indicate that the underlying genetic liability for childhood AGG is consistent across measures.

Exposure to Toenail Heavy Metals and Child Behavior Problems in Nine-Year-Old Children: A Cross-Sectional Study

Behavioral problems are multifactorial and includes perinatal, maternal, family, parenting, socio-economic and personal risk factors, but less is known about the association of postnatal heavy metals on children’s behavioral problems in Pacific Island children. Methods: A cohort of eligible nine-year-old children within a Pacific Island Families longitudinal study were recruited for a cross-sectional study. Child behavior problems were assessed using the child behavior checklist. Heavy metals (including Ni, Cu, Pb, Al, Cr and Cd) were determined in toenails, after acid digestion and analyzed using inductively coupled plasma mass spectrometry. Other factors such as lifestyle (smoking in pregnancy), health outcomes (obesity, health status), demographics (gender, ethnicity, parents’ marital status) and socioeconomic status (household income levels) were also collected. The statistical analysis included t-tests for independent sample and Mann–Whitney U-test, and chi-square or Fisher’s exact tests of independence for comparisons of the proportions. Regression models tested the hypothesized risk factors for behavior outcomes. Results: This observational study enrolled 278 eligible Pacific Island children living in Auckland, New Zealand. The prevalence of behavioral problems in the clinical range was high (22%) but there was no significant association between heavy metals in toenails and adverse behavioral outcomes. Conclusion: Regular monitoring and assessments of children for environmental risk factors, as well as social and lifestyle factors for behavior problems, continues. Alternative indicators of exposure to heavy metal should be evaluated.