Familial confounding of the association between maternal smoking during pregnancy and internalizing disorders in offspring

Long-term adverse influence of smoking during pregnancy on height and body size of offspring at ten years old in the UK Biobank cohort

Background

To explore the long-term relationship between maternal smoking during pregnancy and early childhood growth in the UK Biobank cohort.

Methods

To estimate the effect of maternal smoking during pregnancy on offspring height and body size at ten years old, we performed binary logistic analyses and reported odds ratios (OR) as well as 95% confidence intervals (95%CIs). We also implemented the cross-contextual comparison study to examine whether such influence could be repeatedly observed among three different ethnicities in the UK Biobank cohort (n = 22,140 for White, n = 7094 for South Asian, and n = 5000 for Black). In particular, we conducted the sibling cohort study in White sibling cohort (n = 9953 for height and n = 7239 for body size) to control for unmeasured familial confounders.

Results

We discovered that children whose mothers smoked during pregnancy had greater risk of being shorter or plumper at age ten in the full UK Biobank White cohort, with 15.3% (95% CIs: 13.0%∼17.7%) higher risk for height and 32.4% (95%CIs: 29.5%∼35.4%) larger risk for body size. Similar associations were identified in the South Asian and Black ethnicities. These associations were robust and remained significant in the White sibling cohort (12.6% [95%CIs: 5.0%∼20.3%] for height and 36.1% [95%CIs: 26.3%∼45.9%] for body size) after controlling for family factors.

Conclusion

This study robustly confirms that maternal smoking during pregnancy can promote height deficit and obesity for offspring at ten years old. Our findings strongly encourage mothers to quit smoking during pregnancy for improving growth and development of offspring.

Early Risk of Tobacco Smoke Exposure and Preschoolers' Hot and Cool Inhibitory Control: Promotive and Protective Roles of Maternal Positivity in Early Mother-child Interaction

Early tobacco smoke exposure (TSE) in utero and/or during the first years after birth poses threats to the development of child executive functioning and self-regulation skills, including inhibitory control. Efforts are still needed to examine under what conditions such effects may occur and thus identify modifiable intervention targets. In addition, a distinction between cool and hot inhibitory control is also important to obtain greater nuance in such links. The cool inhibitory control refers to children's suppression of prepotent automatic responses to a distracting stimulus in solving arbitrary and decontextualized problems, whereas the hot inhibitory control refers to children's control of impulse in motivationally and emotionally high-stake situations. Using data derived from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, we examined the links between early risk of TSE and preschoolers' hot and cool inhibitory control and tested the potential promotive/protective roles of maternal positivity in early mother-child interactions. Results indicate that early risk of TSE was negatively linked to child cool inhibitory control when maternal positivity was low, but this link was nonsignificant when maternal positivity was high (i.e., the protective role of maternal positivity). The link between early risk of TSE and child later hot inhibitory control was not moderated by maternal positivity; instead, early risk of TSE and maternal positivity were negatively and positively associated with child hot inhibitory control above and beyond each other, respectively (i.e., the promotive role of maternal positivity). Accordingly, building a tobacco-free environment during pregnancy and infancy likely yields long-term benefits for child self-regulation development. Improving early mothering may offset the negative link between early TSE and child cool inhibitory control and also facilitate child hot inhibitory control even in the face of early TSE.

Maternal smoking during pregnancy, offspring smoking, adverse childhood events, and risk of major depression: a sibling design study

BACKGROUND

Evidence of a biologically plausible association between maternal smoking during pregnancy (MSP) and the risk of depression is discounted by null findings from two sibling studies. However, valid causal inference from sibling studies is subject to challenges inherent to human studies of MSP and biases particular to this design. We addressed these challenges in the first sibling study of MSP and depression conducted among adults past the peak age for the onset of depression, utilizing a prospectively collected and biologically validated measure of MSP and accounting for non-shared as well as mediating factors.

METHODS

We fit GEE binomial regression models to correct for dependence in the risk of depression across pregnancies of the same mother. We also fit marginal structural models (MSM) to estimate the controlled direct effect of MSP on depression that is not mediated by the offspring's smoking status. Both models allow the estimation of within- and between-sibling risk ratios.

RESULTS

The adjusted within-sibling risk ratios (RR_W) from both models (GEE: RR_W = 1.97, CI 1.16-3.32; MSM: RR_W = 2.08, CI 1.04-4.17) evinced an independent association between MSP and risk of depression. The overall effects from a standard model evinced lower associations (GEE: RR_T = 1.12, CI 0.98-1.28; MSM: RR_T = 1.18, CI 1.01-1.37).

CONCLUSIONS

Based on within-sibling information free of unmeasured shared confounders and accounting for a range of unshared factors, we found an effect of MSP on the offspring's risk of depression. Our findings, should they be replicated in future studies, highlight the importance of considering challenges inherent to human studies of MSP and affective disorders.

Prenatal determinants of depressive symptoms in childhood: Evidence from Growing Up in New Zealand

BACKGROUND

Young people who experience depression are at an increased risk of adverse psychosocial and developmental outcomes that can persist over the lifecourse. Identifying maternal prenatal risk factors that may contribute to childhood depressive symptoms can be useful when considering mental health intervention.

METHODS

The current study included 3,925 children from the Growing Up in New Zealand (GUiNZ) study who had complete data for self-reported depressive symptoms and mothers' antenatal information. Depressive symptoms were measured at age 8 using the Centre for Epidemiological Studies Depression Scale for Children (CESD-10) short form questionnaire. Hierarchical linear regression was used to determine the relationship between prenatal factors and depressive symptoms at age 8.

RESULTS

When controlling for sociodemographic characteristics, our hierarchical linear regression revealed that the most significant maternal prenatal predictors of high depressive symptoms at age 8 were maternal perceived stress, smoking during pregnancy, body mass index (BMI) in the overweight/obese range, and paracetamol intake.

LIMITATIONS

One limitation with the current study was a reduction in the sample due to attrition. This may have affected our statistical power, reflected in our modest effect sizes. The sample remained both socioeconomically and ethnically diverse, however our results should be interpreted with respect to the sample and not the whole New Zealand population.

CONCLUSIONS

A combination of maternal mental health and lifestyle factors contribute to depressive symptoms for children, possibly through foetal programming. Our results emphasise the importance of mental and physical health support for expectant mothers.

Maternal smoking during pregnancy and children's mental health at age 22 years: Results of a birth cohort study

BACKGROUND

Early exposures such as maternal smoking can be associated mental disorders. We aimed to analyze the association between maternal smoking during pregnancy (MSDP), generalized anxiety disorder (GAD), and depression in the 1993 birth cohort (Pelotas, Brazil).

METHODS

Data on maternal smoking were collected in the perinatal study, while information on GAD and depression was collected at age 22 years using the Mini International Neuropsychiatric Interview (MINI). Information on maternal mental health, the mediator, was collected at the 11-year follow-up. Simple and multiple logistic regressions were used to assess the association between exposure, outcomes, and analysis of negative controls.

RESULTS

3,781 participants presented complete data. The incidence of GAD was 10.4%, depression 2.9%, and smoking during pregnancy 32.6%. The children of mothers who smoked had a 45% higher chance of developing GAD at age 22 years (OR 1.45; 95%CI 1.18; 1.80) and 75% higher chance of depression (OR 1.75; 95%CI 1.18; 2.59). Also, the higher the number of cigarettes smoked. the higher was the chance for the development of GAD. Paternal smoking was not associated with the outcomes. The mother's mental health accounted for 18.2% of the association between maternal smoking and GAD, and for 13.4% for maternal smoking and depression.

LIMITATIONS

Data for smoking during pregnancy were collected through a self-report. Residual confusion due to important variables cannot be ruled out.

CONCLUSIONS

MSDP was associated with the mental health of children in early adulthood. However, a small part of the effect found was mediated by the mother's mental health.

Research Review: Developmental origins of depression - a systematic review and meta-analysis

BACKGROUND

Many observational studies have found a direct association between adverse in utero, perinatal and postnatal exposures and offspring's depression. These findings are consistent with the 'developmental origins of disease hypothesis'. But no review has comprehensively summarized the roles of these exposures. This review aims to systematically scrutinize the strength of associations between individual prenatal, perinatal, and postnatal exposures and subsequent depression in offspring.

METHODS

We conducted a systematic review and meta-analysis to synthesize the literature from the EMBASE, HealthStar, PsychoInfo, and Medline databases since their inception to September 1, 2019. English language articles on population-based prospective cohort studies examining the associations between in utero, perinatal, and postnatal exposures and offspring's depression were searched. Random-effects models were used to calculate pooled estimates, and heterogeneity and sensitivity tests were conducted to explore potential confounders in the relationships of depression and early-life factors. Qualitative analysis was also conducted.

RESULTS

Sixty-four prospective cohort studies with 28 exposures studied in the relationships to offspring's depression met inclusion criteria. The meta-analysis found 12 prenatal, perinatal, and postnatal characteristics were associated with an increased risk of depression in offspring: low birth weight, premature birth, small gestational age, maternal education, socioeconomic status, having younger parents (<20 years), having older parents (≥35 years), maternal smoking, paternal smoking, maternal stress, maternal anxiety, and prenatal depression. Heterogeneity and sensitivity tests supported the findings. By and large, study characteristics had no effects on conclusions. Qualitative analyses generally supported the findings of meta-analysis and reported on additional risk factors.

CONCLUSIONS

This review provides a robust and comprehensive overview of the lasting psychopathological effects of in utero, perinatal, and postnatal exposures. The findings highlight the need for clinical and public health interventions focusing on the identified risk factors. Large prospective cohort studies are warranted to investigate the combined effects of multiple co-existing early-life exposures.

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.

Prenatal alcohol and tobacco use and the risk of depression in offspring at age of 17 years: findings from the Raine Study

BACKGROUND

Prenatal alcohol and tobacco exposures have been associated with adverse mental health consequences in offspring. The objective of this study was to test the associations between maternal prenatal alcohol and tobacco exposures and depressive symptoms in the offspring, adjusting for a wide range of potential confounders.

METHODS

We used data from 1168 mother-offspring pairs from the Raine Study based in Perth, Western Australia. Depressive symptoms at age 17 years were measured using the Beck Depression Inventory for Youth (BDI-Y). Associations between prenatal alcohol and tobacco use and the risk of depressive symptoms in offspring were estimated by risk ratios (RR) derived with multivariable log-binomial regression.

RESULTS

Among offspring who were assessed for depressive symptoms, 5% were born to mothers who consumed six or more standard drinks of alcohol per week during pregnancy and 20% were exposed to prenatal tobacco. After adjustment for confounders, depressive symptoms at the age of 17 years remained associated with maternal alcohol use of six or more standard drinks per week [RR 1.59 (95% CI: 1.11-2.26)] and any tobacco use [RR 1.36 (95% CI: 1.05-1.79)] during the first trimester of pregnancy.

CONCLUSION

Offspring exposed to prenatal alcohol and tobacco use had greater risks of depressive symptoms compared with unexposed offspring, suggesting early screening and prevention of these exposures could possibly reduce depressive symptoms in offspring.

Prenatal tobacco use and the risk of mood disorders in offspring: a systematic review and meta-analysis

PURPOSE

It is plausible that offspring born to mothers using tobacco during pregnancy may have increased risk of mood disorders (depression and bipolar disorders); however, mixed results have been reported. We conducted a systematic review and meta-analysis to investigate the magnitude and consistency of associations reported between prenatal tobacco use and mood disorders in offspring.

METHODS

We systematically searched EMBASE, SCOPUS, PubMed and Psych-INFO for studies on mood disorders and prenatal tobacco use. Methodological quality of studies was assessed with the revised Newcastle-Ottawa Scale. We estimated pooled relative risk (RR) with inverse variance weighted random-effects meta-analysis. We performed leave-one-out analyses, and stratified analyses by a subgroup (depression and bipolar disorder). Potential publication bias was assessed by inspection of the funnel plot and Egger's test for regression asymmetry. This study protocol was prospectively registered in PROSPERO (CRD42017060037).

RESULTS

Eight cohort and two case-control studies were included in the final meta-analysis. We found an increased pooled relative risk of mood disorders in offspring exposed to maternal prenatal tobacco use RRs 1.43 (95% CI 1.27-1.60) compared to no prenatal tobacco use. Similarly, the pooled relative risks of bipolar and depressive disorders in offspring were 1.44, (95% CI 1.15-1.80) and 1.44, (95% CI 1.21-1.71), respectively. Moreover, the pooled estimated risk of mood disorders was not significantly attenuated in the studies that reported sibling comparison results [RR = 1.21 (95% CI 1.04-1.41)].

CONCLUSION

Taken together, there was strong evidence for a small (RR < 2) association between prenatal tobacco use and mood disorders in offspring.

Prenatal and perinatal risk factors for anxiety disorders among children and adolescents: A systematic review

BACKGROUND

Prenatal and perinatal risk factors for anxiety disorders have rarely been studied, even though they are highly prevalent in children and adolescents. It is important to identify the common risk factors, so that targeted preventive care and early interventions can be provided.

METHODS

A systematic review of the PubMed and PsycInfo databases was conducted to 25 October 2019, according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses guidelines. The protocol was registered on the Prospective Register of Systematic Reviews and the quality assessment was carried out using the Joanna Briggs tools.

RESULTS

The review identified 31 studies from eight countries, including three register studies. Cohort sizes ranged from 69 to 89,404 and diagnoses cases ranged from 4 to 7867. Although various risk factors had been researched, only few of them had been repeatedly studied and the findings were highly inconsistent. The associations between the different risk factors and anxiety disorders seemed weak compared to many other psychiatric disorders, but preterm birth and maternal somatic illnesses may increase the risk for anxiety disorders in offspring.

LIMITATIONS

The studies varied considerably by study design, risk factors and anxiety disorders studied, sample sizes and follow up periods.

CONCLUSIONS

Prenatal and perinatal risk factors for anxiety disorders have been under-researched, compared to other psychiatric disorders. Our systematic review found weak links to prenatal events, but flagged up preterm birth and maternal somatic illnesses as possible avenues for future research.

The Effect of Smoking during Pregnancy on Severity and Directionality of Externalizing and Internalizing Symptoms: A Genetically Informed Approach

The objective was to examine the association between maternal smoking during pregnancy (SDP) and (I) severity and (II) directionality of externalizing and internalizing symptoms in a sample of sibling pairs while rigorously controlling for familial confounds. The Missouri Mothers and Their Children Study is a family study (N = 173 families) with sibling pairs (aged 7 to 16 years) who are discordant for exposure to SDP. This sibling comparison study is designed to disentangle the effects of SDP from familial confounds. An SDP severity score was created for each child using a combination of SDP indicators (timing, duration, and amount). Principal component analysis of externalizing and internalizing behavior, assessed with the Child Behavior Checklist and Teacher Report Form, was used to create symptom severity and directionality scores. The variance in severity and directionality scores was primarily a function of differences between siblings (71% and 85%, respectively) rather than differences across families (29% and 15%, respectively). The severity score that combines externalizing and internalizing symptom severity was not associated with SDP. However, a significant within-family effect of SDP on symptom directionality (b = 0.07, p = 0.04) was observed in the sibling comparison model. The positive directionality score indicates that SDP is associated with differentiation of symptoms towards externalizing rather than internalizing symptoms after controlling for familial confounds with a sibling comparison model. This supports a potentially causal relationship between SDP and externalizing behavior.

Familial confounding of the association between maternal smoking in pregnancy and autism spectrum disorder in offspring

Evidence supports no link between maternal smoking in pregnancy and autism spectrum disorder (autism) overall. To address remaining questions about the unexplained heterogeneity between study results and the possibility of risk for specific autism sub-phenotypes, we conducted a whole-population cohort study in Denmark. We followed births 1991-2011 (1,294,906 persons, including 993,301 siblings in 728,271 families), from 1 year of age until an autism diagnosis (13,547), death, emigration, or December 31, 2012. Autism, with and without attention deficit hyperactivity disorder (ADHD) and with and without intellectual disability (ID) were based on ICD-8 and ICD-10 codes from Danish national health registers, including 3,319 autism + ADHD, 10,228 autism - no ADHD, 2,205 autism + ID, and 11,342 autism - no ID. We estimated hazard ratios (HRs) and 95% confidence intervals (95% CIs) between any maternal smoking (from birth records) and autism (or sub-phenotypes) using survival models with robust standard errors, stratifying by birth year and adjusting for child sex, parity, and parental age, education, income, and psychiatric history. To additionally address confounding using family designs, we constructed a maternal cluster model (adjusting for the smoking proportion within the family), and a stratified sibling model. Associations with maternal smoking and autism were elevated in conventional adjusted analyses (HR of 1.17 [1.13-1.22]) but attenuated in the maternal cluster (0.98 [0.88-1.09]) and sibling (0.86 [0.64-1.15]) models. Similarly, risks of autism sub-phenotypes with maternal smoking were attenuated in the family-based models. Together these results support that smoking in pregnancy is not linked with autism or select autism comorbid sub-phenotypes after accounting for familial confounding. Autism Res 2020, 13: 134-144. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Smoking during pregnancy has many harmful impacts, which may include harming the baby's developing brain. However, in a study of thousands of families in Denmark, it does not appear that smoking in pregnancy leads to autism or autism in combination with intellectual problems or attention deficits, once you account for the way smoking patterns and developmental disabilities run in families.

Paternal nicotine exposure in rats produces long-lasting neurobehavioral effects in the offspring

Studies of intergenerational effects of parental chemical exposure have principally focused on maternal exposure, particularly for studies of adverse neurobehavioral consequences on the offspring. Maternal nicotine exposure has long been known to cause adverse neurobehavioral effects on the offspring. However, paternal toxicant exposure has also been found to cause neurobehavioral toxicity in their offspring. Recent work suggests that paternal nicotine exposure can have epigenetic effects, although it remains unclear whether such changes lead to neurobehavioral effects. In the current study, we investigated the effects of paternal nicotine exposure on neurobehavioral development of their offspring. Male Sprague-Dawley rats were exposed to 0 or 2 mg/kg/day nicotine (sc) for 56 consecutive days with two consecutive 2ML4 osmotic minipumps. Following treatment, these males were mated with drug-naïve female rats. Offspring of both sexes were tested in a behavioral battery to assess locomotion, emotional function and cognition. Paternal nicotine exposure did not impact offspring viability, health or growth. However, behavioral function of the offspring was significantly altered by paternal nicotine exposure. Male offspring with paternal nicotine exposure exhibited locomotor hyperactivity in the Figure-8 apparatus when tested during adolescence. When retested in adulthood and regardless of sex, offspring of the nicotine exposed father showed significantly reduced habituation of locomotor activity over the course of the session. Compared to controls, female offspring of nicotine-exposed fathers showed significantly reduced response latency in the radial arm maze test. In addition to locomotor hyperactivity, the offspring of nicotine-exposed fathers also showed significantly diminished habituation in the novel object recognition test. These results indicate that chronic paternal nicotine exposure can impact the behavior of offspring, producing locomotor hyperactivity and impaired habituation.

Locus of control is associated with tobacco and alcohol consumption in young adults of the Avon Longitudinal Study of Parents and Children

Individuals appraise events as a consequence of their own actions (i.e. internal locus of control, LoC) or as the outcome of chance or others' will (i.e. external LoC). We hypothesized that having a more external LoC would be associated with higher risk of tobacco and alcohol use. Few studies have examined this association using large prospective data. We evaluated within the Avon Longitudinal Study of Parents and Children (ALSPAC) the associations between LoC at 16 and tobacco and alcohol consumption at 17 and 21 years using logistic regression. A more external LoC at age 16 (N = 4656) was associated with higher odds of being a weekly smoker at age 17 (OR 1.18, 95% CI 1.10-1.25) and 21 (OR 1.14, 95% CI 1.07-1.21) and with dependence measured using the Fagerström Test of Nicotine Dependence at age 17 (OR 1.26, 95% CI 1.05-1.51) and 21 (OR 1.25, 95% CI 1.05-1.49). Individuals with external LoC at age 16 were more likely to be hazardous drinkers according to the Alcohol Use Disorders Identification Test at age 17 (OR 1.09, 95% CI 1.04-1.15) but not at 21 (OR 1.01, 95% CI 0.96-1.06). Having a more external LoC at age 16 is associated with increased tobacco consumption at age 17 and 21 and alcohol consumption at 17 years. LoC may represent an intervention target for preventing substance use and dependence.

Prenatal maternal smoking, maternal offending, and offspring behavioural and cognitive outcomes in early childhood

BACKGROUND

Maternal smoking during pregnancy and parental offending are both linked to adverse offspring outcomes. Few studies have examined how these exposures together influence diverse offspring outcomes in early childhood.

AIMS

To examine associations between quantity of prenatal maternal smoking and frequency of maternal offending and offspring behavioural and cognitive outcomes at age 5 years.

METHODS

Over 66,000 Australian children (mean age 5.6 years) were drawn from an intergenerational data linkage study. Unadjusted and adjusted logistic regressions were conducted for the two key exposures (maternal prenatal smoking and mother having at least two criminal convictions) and offspring behavioural and cognitive vulnerabilities. Population attributable fractions (PAFs) were also estimated for each outcome for the two exposures.

RESULTS

Prenatal smoking and maternal offending were, separately and together, associated with most of the developmental vulnerabilities examined, even after adjusting for other familial and prenatal risk factors. PAFs for prenatal smoking ranged from 5.3% to 15.8%, and PAFs for maternal offending ranged from 3.4% to 11.8% across the offspring outcomes.

CONCLUSIONS

Maternal smoking during pregnancy and maternal offending were uniquely associated with a range of offspring vulnerabilities, but mothers who smoked during pregnancy tended to experience multiple problems that should also be considered as indicators of child vulnerabilities. While early behavioural difficulties were evident in these children, it was striking that they were also likely to have cognitive vulnerabilities. Early intervention to support cognitive development in these children may minimise their risk of academic underachievement, long-term disadvantage, and even offending.

Maternal smoking during pregnancy and offspring personality in childhood and adulthood

OBJECTIVE

Maternal smoking during pregnancy (MSDP) has been associated with offspring internalizing and externalizing disorders. The purpose of this research is to examine whether MSDP is also associated with variations in normal personality traits in childhood and adulthood.

METHOD

This study uses four independent samples (total N = 16,323) to examine whether there are mean-level differences in offspring personality traits by MSDP, controlling for relevant sociodemographic factors. Two samples are of children (Ns = 3,782 and 3,841) and two samples are of adults (Ns = 1,786 and 6,914).

RESULTS

A meta-analysis across the four samples indicated that offspring of mothers who did smoke during pregnancy scored higher in Neuroticism (p = .000) and Extraversion (p = .003) and lower in Conscientiousness (p = .002) than offspring of mothers who did not smoke during pregnancy. The association between MSDP and Neuroticism and Conscientiousness held across both childhood and adulthood and when propensity score matching was used, whereas the association with Extraversion was only apparent in adulthood and did not hold with propensity scores.

CONCLUSIONS

These results suggest that MSDP is associated with individual differences in psychological traits in childhood and adulthood and may be one prenatal factor that contributes to trait Neuroticism and Conscientiousness.

Inhibitory control in siblings discordant for exposure to maternal smoking during pregnancy

Maternal smoking during pregnancy (SDP) has been linked to poorer offspring executive function across development, but SDP does not occur independent of other familial risk factors. As such, poor and inconsistent control for potential confounds, notably shared familial (i.e., genetic and environmental) confounds, preclude concluding causal effects of SDP on child outcomes. We examined the within-family association between SDP and one component of executive function, inhibitory control, in a sample of families (N = 173) specifically selected for sibling pairs discordant for exposure to SDP. Thus, the present study examines if the SDP-inhibitory control association withstands rigorous control for potential child and familial confounds. 79% of the variation in child inhibitory control was attributable to within-family differences and 21% was attributable to differences between families, indicating that the variability in inhibitory control was primarily a function of differences between siblings rather than differences across families. Further, the association between SDP and inhibitory control was fully attenuated when confounds were considered. These findings suggest that co-occurring vulnerabilities act as more salient risk factors for poorer child inhibitory control than SDP and may serve as effective targets of interventions seeking to improve children's inhibitory control in families with nicotine dependent mothers. (PsycINFO Database Record