The roles of familial transmission and smoking during pregnancy on executive function skills: A sibling-comparison study

This research examines maternal smoking during pregnancy and risk for poorer executive function in siblings discordant for exposure. Data (N = 173 families) were drawn from the Missouri Mothers and Their Children study, a sample, identified using birth records (years 1998-2005), in which mothers changed smoking behavior between two pregnancies (Child 1 [older sibling]: M age = 12.99; Child 2 [younger sibling]: M age = 10.19). A sibling comparison approach was used, providing a robust test for the association between maternal smoking during pregnancy and different aspects of executive function in early-mid adolescence. Results suggested within-family (i.e., potentially causal) associations between maternal smoking during pregnancy and one working memory task (visual working memory) and one response inhibition task (color-word interference), with increased exposure associated with decreased performance. Maternal smoking during pregnancy was not associated with stop-signal reaction time, cognitive flexibility/set-shifting, or auditory working memory. Initial within-family associations between maternal smoking during pregnancy and visual working memory as well as color-word interference were fully attenuated in a model including child and familial covariates. These findings indicate that exposure to maternal smoking during pregnancy may be associated with poorer performance on some, but not all skills assessed; however, familial transmission of risk for low executive function appears more important.

Within-person changes of cortisol, dehydroepiandrosterone, testosterone, estradiol, and progesterone in hair across pregnancy, with comparison to a non-pregnant reference group

The literature on hormone changes in pregnancy has focused largely on cortisol, and changes in sample average concentrations. Within-person changes and variability in hormone concentrations are less commonly reported, particularly for sex hormones, and especially measured in hair. Using a prospective sample of pregnant women and a non-pregnant comparison group, we examined changes in five steroid hormones in hair. Non-pregnant women were recruited from the same area with parallel procedures and assessment timeline. Participants include 68 women (34 pregnant, average age ​= ​29.14, and 34 non-pregnant; average age ​= ​27.18) who were predominately non-Hispanic White (83%), and above the 2020 poverty line (75%). Pregnant women provided 3 ​cm hair samples and completed questionnaires three times during pregnancy: 1) at 12 weeks, 2) at 26 weeks, and 3) at 38 weeks. Non-pregnant women provided 3 ​cm hair samples and completed questionnaires three times, at baseline, 14 weeks later, and 12 weeks after that to mirror the assessment schedule of the pregnant group. There was clear evidence that progesterone was higher initially and increased dramatically across pregnancy whereas non-pregnant patterns showed no systematic change. There was suggestive evidence that cortisol and estradiol increased over pregnancy and in non-pregnant women similarly across the same time course. There was suggestive evidence that DHEA decreased across pregnancy, particularly early in pregnancy, differently from patterns in non-pregnant women over the same time course. Most importantly, there was substantial variability of hormone concentrations and many different within-person patterns of changes in these hormones over time, with little evidence of systematic change or stability within-individuals. Moving beyond discussing sample averages to including within-person and non-linear changes in studies of hormones-behavior associations during pregnancy is an important future direction for further investigation.

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We describe within-person hormone changes in pregnant and non-pregnant women.

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There were many observed patterns of change over time within individuals.

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Average hair progesterone increased and DHEA decreased across early pregnancy.

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Average hair cortisol and estradiol weakly increased in both groups of women.

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There was far more variability over time than systematic change or stability.

Disruptive Behavior in Siblings Discordant for Exposure to Maternal Smoking During Pregnancy: A Multi-rater Approach

INTRODUCTION

Maternal smoking during pregnancy (SDP) is associated with disruptive behavior. However, there is debate whether the SDP-disruptive behavior association is a potentially causal pathway or rather a spurious effect confounded by shared genetic and environmental factors.

AIMS AND METHODS

The Missouri Mothers and Their Children Study is a sibling comparison study that includes families (n = 173) selected for sibling pairs (aged 7-16 years) discordant for SDP. Critically, the sibling comparison design is used to disentangle the effects of SDP from familial confounds on disruptive behavior. An SDP severity score was created for each child using a combination of SDP indicators (timing, duration, and amount of SDP). Multiple informants (parents and teachers) reported on disruptive behavior (i.e., DSM-IV semi-structured interview, the Child Behavior Checklist, and Teacher Report Form).

RESULTS

The variability in disruptive behavior was primarily a function of within-family differences (66%-100%). Consistent with prior genetically informed approaches, the SDP-disruptive behavior association was primarily explained by familial confounds (genetic and environmental). However, when using a multi-rater approach (parents and teachers), results suggest a potentially causal effect of SDP on disruptive behavior (b = 0.09, SE = 0.04, p = 0.03). The potentially causal effect of SDP remained significant in sensitivity analyses.

DISCUSSION

These findings suggest that familial confounding likely plays a complex role in the SDP-disruptive behavior association when examining both parent and teacher reports of behavior. Importantly, the current study highlights the importance of multiple raters, reflecting a more comprehensive measure of complex behaviors (e.g., disruptive behavior) to examine the teratogenic effects of SDP.

IMPLICATIONS

Our study provides additional evidence that controlling for genetic and family factors is essential when examining the effect of SDP on later behavioral problems, as it explains a portion of the association between SDP and later behavioral problems. However, we found a significant association between SDP and disruptive behavior when using a multi-rater approach that capitalizes on both parent and teacher report, suggesting that parent and teacher ratings capture a unique perspective that is important to consider when examining SDP-behavior associations.

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.

Childhood Protective Factors and a Prevention Program Reduce Later Problem Behaviors

Prior research has yet to elucidate how constellations of protective factors in childhood and prevention efforts simultaneously may influence youth involvement in problem behaviors across different points in development. The current study examines how latent classes of social and emotional learning (SEL) skills, parent-child relationships, and peer influences in third grade and receipt of an ongoing SEL intervention predict substance use and violence in fifth and eighth grade. The urban, predominantly low-income, sample (N = 1,169) was nested in 14 schools that were randomly assigned to the Positive Action program or business-as-usual. Membership in a latent class reflecting protective childhood factors predicted less substance use and violence in fifth grade; however, the SEL program predicted less substance use and violence in eighth grade. Findings generally support that SEL interventions can successfully target and boost developmentally appropriate positive behaviors and can prevail over initial risk factors with enough time and exposure.

Examining the Factor Structure of the Home Mathematics Environment to Delineate Its Role in Predicting Preschool Numeracy, Mathematical Language, and Spatial Skills

A growing body of evidence suggests that the ways in which parents and preschool children interact in terms of home-based mathematics activities (i.e., the home mathematics environment; HME) is related to children's mathematics development (e.g., primarily numeracy skills and spatial skills); however, this body of evidence is mixed with some research supporting the relation and others finding null effects. Importantly, few studies have explicitly examined the factor structure of the HME and contrasted multiple hypothesized models. To develop more precise models of how the HME supports children's mathematics development, the structure of the HME needs to be examined and linked to mathematics performance. The purpose of this study was to extend prior work by replicating the factor structure of the HME (as one general HME factor and three specific factors of direct numeracy, indirect numeracy, and spatial) and using those factors to predict direct assessments of children's numeracy, mathematical language, and spatial skills. It was hypothesized that the general HME factor would be related to each direct assessment, the direct numeracy factor would be related to both numeracy and mathematical language, and the spatial factor would be related to spatial skills. Using a sample of 129 preschool children (M age = 4.71 years, SD = 0.55; 46.5% female), a series of confirmatory factor analyses were conducted. Results diverged somewhat from prior work as the best fitting model was a bifactor model with a general HME factor and two specific factors (one that combined direct and indirect numeracy activities and another of spatial activities) rather than three specific factors as had previously been found. Further, structural equation modeling analyses suggested that, in contrast to expectations, only the direct + indirect numeracy factor was a significant predictor of direct child assessments when accounting for age, sex, and parental education. These findings provide evidence that a bifactor model is important in understanding the structure of the HME, but only one specific factor is related to children's outcomes. Delineating the structure of the HME, and how specific facets of the HME relate to children's mathematics skills, provides a strong foundation for understanding and enhancing the mechanisms that support mathematics development.

Parenting and prenatal risk as moderators of genetic influences on conduct problems during middle childhood

This study examines interactions of heritable influences, prenatal substance use, and postnatal parental warmth and hostility on the development of conduct problems in middle childhood for boys and girls. Participants are 561 linked families, collected in 2 cohorts, including birth parents, adoptive parents, and adopted children. Heritable influences on internalizing and externalizing (including substance use) problems were derived from birth mothers' and fathers' symptoms, diagnoses, and age of onset from diagnostic interviews, and the proportion of first-degree relatives with the same type of problems. Smoking during pregnancy (SDP) and alcohol use during pregnancy were assessed retrospectively from birth mothers at 5 months postpartum. Earlier externalizing problems and parental warmth and hostility and were assessed at 1 assessment prior to the outcome (Cohort II: 4.5 years; Cohort I: 7 years). Conduct problems were symptoms from a diagnostic interview assessed at age 6 (Cohort II) or 8 (Cohort I). Findings from regression analyses suggest that (a) SDP plays an important role for the development of conduct problems, (b) some relatively well-accepted effects (e.g., parental hostility) were less important when simultaneously considering multiple factors influencing the development of conduct problems, and (c) main effects of genetic risk and SDP, and interactions among genetic risk and postnatal warmth, SDP and postnatal warmth, and genetic risk, SDP, and postnatal hostility for conduct problems were important for boys' but not girls' conduct problems. Replication is needed, but the current results provide preliminary but empirically grounded hypotheses for future research testing complex developmental models of conduct problems. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Individual and Sibling Characteristics: Parental Differential Treatment and Adolescent Externalizing Behaviors

Adolescents' reports of parental differential treatment have been linked to increased externalizing behaviors. The current study investigated whether adolescent self-esteem and sibling relationship characteristics (age-spacing and sibling relationship quality) moderated associations between parental differential treatment and later externalizing behavior. Data was gathered at two assessments from 708 sibling pairs (94% White; 51% male; same-gender pairs <4 years apart in age). Older/younger siblings were aged M_Assessment1 = 13.5/12.1 and M_Assessment2 = 16.2/14.7 years. We found that higher levels of maternal differential treatment predicted greater residualized gains in externalizing behavior among older siblings who were (a) the same age as their sibling or near-to and had low self-esteem or (b) three years older than their sibling and had higher self-esteem. Higher levels of paternal differential treatment predicted greater residual gains in externalizing for older siblings with wider age ranges (regardless of self-esteem), and among older siblings with high levels of self-esteem (regardless of age difference). Surprisingly, maternal differential treatment was protective in one case: for adolescents with low self-esteem who were at least three years older than their siblings, maternal differential treatment predicted reduced externalizing behaviors. Paternal differential treatment was protective for more youth than maternal differential treatment: older siblings with low self-esteem who experienced paternal differential treatment exhibited decreased externalizing behaviors across adolescence, regardless of age difference. The findings highlight the importance of self-esteem and sibling age-spacing as particularly salient contextual influences in older siblings' perceptions of maternal and paternal differential treatment, and that maternal and especially paternal differential treatment does not always serve as a risk factor for externalizing problems.

Prenatal substance exposure and offspring development: Does DNA methylation play a role?

The period of in utero development is one of the most critical windows during which adverse conditions and exposures may influence the growth and development of the fetus as well as its future postnatal health and behavior. Maternal substance use during pregnancy remains a relatively common but nonetheless hazardous in utero exposure. For example, previous epidemiological studies have associated prenatal substance exposure with reduced birth weight, poor developmental and psychological outcomes, and increased risk for diseases and behavioral disorders (e.g., externalizing behaviors like ADHD, conduct disorder, and substance use) later in life. Researchers are now learning that many of the mechanisms whereby adverse in utero exposures may affect key pathways crucial for proper fetal growth and development are epigenetic in nature, with the majority of work in humans considering DNA methylation specifically. This review will explore the research to date on epigenetic alterations tied to maternal substance use during pregnancy and will also discuss the possible role of DNA methylation in the robust relationship between maternal substance use and later behavioral and developmental sequelae in offspring.