Cognitive and Behavioural Attention in Children with Low-Moderate and Heavy Doses of Prenatal Alcohol Exposure: a Systematic Review and Meta-analysis

Clinical Features of Typically Developing Children with and without Prenatal Alcohol Exposure

OBJECTIVE

To determine if prenatal alcohol exposure (PAE) affected physical and cognitive/behavioral outcomes in apparently typically developing, first-grade children.

STUDY DESIGN

Three groups were compared: children with fetal alcohol spectrum disorders (FASD), children with PAE without FASD, and children without PAE.

RESULTS

The 3 groups were significantly different on most physical traits and fewer neurodevelopmental traits. Two-group comparisons of exposed and unexposed, non-FASD groups were statistically different on: height, weight, body mass index (BMI), and palpebral fissure length. Neurobehavioral outcomes were significant in three-group, but not 2-group comparisons. Few sex differences were observed; however, sex ratios indicated fewer male offspring in first grade among women who consumed 6+ drinks per occasion during pregnancy. For weight, head circumference (OFC), BMI, rural residence, and drinking measures, mothers of exposed children without FASD were intermediaries between, and significantly different from, the other maternal groups. Adjusted for socioeconomic covariates, multivariate ANCOVA, three-group comparisons of the children were significantly different for cognitive/behavioral variables (P < .001); however, 2-group neurobehavior comparisons for children without FASD were not significant (P ≥ .05). Physical trait multivariate ANCOVA comparisons of the non-FASD groups were significant only for weight (P < .004) when tested univariately and through stepdown analysis. Socioeconomic-adjusted trend plots were in the expected direction for nonverbal IQ, attention, height, weight, OFC, palpebral fissure length, and total dysmorphology score.

CONCLUSIONS

Even when meeting developmental norms, children with PAE exhibited trends of poorer growth and cognitive/behavioral traits than children without PAE. These findings support the notion that abstinence during pregnancy is best.

Environmental enrichment reverses prenatal ethanol exposure-induced attention-deficits in rats

Introduction

There is a high prevalence of fetal alcohol spectrum disorders (FASD) in the US and the world, which is caused by prenatal ethanol exposure (PE). Most individuals with FASD show attention deficit hyperactivity disorder (ADHD) -like symptoms. Using a rat model of FASD, we have successfully demonstrated that moderate and heavy PE leads to persistent attention deficits, including augmented impulsivity and impaired sustained attention. Anxiety is another primary symptom of FASD. Anxiety and ADHD are closely associated in clinical studies. However, the causal relationship between anxiety and ADHD is not clear. In the present study, we used the strategy of environmental enrichment to reduce anxiety after PE in rats and investigated if attention deficits could be ameliorated.

Methods

A 2nd-trimester binge-drinking pattern of heavy PE was used. Environmental enrichment consisted of neonatal handling and postweaning complex housing. Action impulsivity and sustained attention were tested in adult males and females using the 2-choice reaction time task.

Results

The results show environmental enrichment effectively ameliorated action impulsivity and improved sustained attention in male and female PE rats. Action impulsivity was also improved in control rats with environmental enrichment. In addition, environmental enrichment improved the efficiency of obtaining rewards in male and female control but not PE rats. Environmental enrichment altered the pattern of reaction time components, favoring slower movement initiation but faster movement.

Discussion

These observations support that environmental enrichment could be an effective strategy in ameliorating ADHD-like symptoms in FASD. The reduced anxiety could contribute to such an effect.

The association between neighborhood environment, prenatal exposure to alcohol and tobacco, and structural brain development

Prenatal alcohol and tobacco exposure affects child brain development. Less is known about how neighborhood environment (built, institutional, and social) may be associated with structural brain development and whether prenatal exposure to alcohol or tobacco may modify this relationship. The current study aimed to examine whether neighborhood environment is associated with brain volume at age 9-11, and whether prenatal exposure to alcohol or tobacco modifies this relationship. Baseline data from Adolescent Brain and Cognitive Development (ABCD) study was analyzed (N = 7,887). Neighborhood environment was characterized by 10 variables from the linked external dataset. Prenatal alcohol and tobacco exposures were dichotomized based on the developmental history questionnaire. Bilateral volumes of three regions of interests (hippocampal, parahippocampal, and entorhinal) were examined as outcomes. High residential area deprivation was associated with smaller right hippocampal volume. Prenatal alcohol exposure was associated with larger volume in left parahippocampal and hippocampal regions, while prenatal tobacco exposure was associated with smaller volumes in bilateral parahippocampal, right entorhinal, and right hippocampal regions. In children without prenatal tobacco exposure, high residential area deprivation was associated with smaller right hippocampal volumes. In contrast, neighborhood environment was not significantly associated with brain volumes in children with prenatal tobacco exposure. In summary, neighborhood environment plays a role in child brain development. This relationship may differ by prenatal tobacco exposure. Future studies on prenatal tobacco exposure may need to consider how postnatal neighborhood environment interacts with the teratogenic effect.

Prenatal alcohol exposure is associated with altered feto-placental blood flow and sex-specific placental changes

BACKGROUNDPrenatal alcohol exposure (PAE) around conception in preclinical models results in placental insufficiency, likely contributing to offspring abnormalities. Altered placental DNA methylation (DNAm) and gene expression suggest epigenetic mechanisms, perhaps involving impacts on methyl donor levels. PAE around conception in women is common but placental effects are rarely examined. This cohort study investigated associations between PAE around conception and intake/plasma measures of the methyl donors folate and choline, feto-placental blood flow, and placental growth measures, gene expression, and DNAm.METHODSPregnant participants delivered at Mater Mothers' Hospital, Brisbane, Queensland, Australia (n = 411). Dietary intake of choline and folate were calculated and plasma concentrations measured using mass spectrometry (MS) and clinical immunoanalyzer, respectively. Cerebroplacental ratio (CPR) was calculated using Doppler measurements. Placentas were weighed/measured at delivery and samples used to quantify methyl donors (MS), global DNAm (ELISA), and gene expression (quantitative PCR). Data were compared between control/abstinent and PAE groups, by fetal sex.RESULTSA CPR <5th-centile, indicating fetal brain sparing because of placental insufficiency, was found in 2% of controls and 18% of the PAE group, mostly male fetuses (63%). Compared with controls, male PAE placentas had reduced mean thickness and placental growth factor mRNA and DNAm, whereas female PAE placentas had increased S-adenosylmethionine and a trend toward increased DNAm.CONCLUSIONPAE around conception is associated with reduced CPR and altered placental growth measures, particularly in males, with potential implications for future health.FUNDINGNational Health and Medical Research Council (APP1191217) and Mary McConnel Career Boost Program for Women in Paediatric Research (WIS132020).

Exploring the intersection of polygenic risk scores and prenatal alcohol exposure: Unraveling the mental health equation

BACKGROUND

Prenatal alcohol exposure poses significant risks to offspring mental health. However, the interplay between genetic predispositions to mental health disorders and prenatal alcohol exposure remains incompletely understood, limiting our ability to develop effective interventions for these conditions.

METHODS

Data from the Adolescent Brain and Cognitive Development (ABCD) Study were analyzed to explore associations between polygenic risk scores (PRS) for mental disorders and maternal alcohol consumption during pregnancy. Logistic regression and structural equation modeling were utilized to assess these relationships.

RESULTS

Maternal alcohol consumption after pregnancy awareness was significantly associated with an increased genetic risk for specific mental health disorders, particularly bipolar disorder in offspring. The relationship between maternal alcohol consumption and mental health outcomes was influenced by polygenic risk scores, with both externalizing and internalizing problems being affected.

CONCLUSIONS

Our findings highlight the specific interaction between increased genetic risk for bipolar disorder and prenatal alcohol exposure in shaping offspring mental health outcomes. The significant associations we observed underscore the importance of considering both polygenic risk scores and prenatal alcohol exposure when assessing mental health risks in children. These insights emphasize the need for targeted interventions that address both genetic predispositions and environmental exposures to better understand and mitigate the impact on offspring mental health.

Moderate Prenatal Alcohol Exposure Increases Toll-like Receptor Activity in Umbilical Cord Blood at Birth: A Pilot Study

The prevalence of prenatal alcohol exposure (PAE) is increasing, with evidence suggesting that PAE is linked to an increased risk of infections. PAE is hypothesized to affect the innate immune system, which identifies pathogens through pattern recognition receptors, of which toll-like receptors (TLRs) are key components. We hypothesized that light-to-moderate PAE would impair immune responses, as measured by a heightened response in cytokine levels following TLR stimulation. Umbilical cord samples (10 controls and 8 PAE) from a subset of the Ethanol, Neurodevelopment, Infant and Child Health Study-2 cohort were included. Peripheral blood mononuclear cells (PMBCs) were stimulated with one agonist (TLR2, TLR3, TLR4, or TLR9). TLR2 agonist stimulation significantly increased pro-inflammatory interleukin-1-beta in the PAE group after 24 h. Pro- and anti-inflammatory cytokines were increased following stimulation with the TLR2 agonists. Stimulation with TLR3 or TLR9 agonists displayed minimal impact overall, but there were significant increases in the percent change of the control compared to PAE after 24 h. The results of this pilot investigation support further work into the impact on TLR2 and TLR4 response following PAE to delineate if alterations in levels of pro- and anti-inflammatory cytokines have clinical significance that could be used in patient management and/or attention to follow-up.

Prenatal ethanol exposure leads to persistent anxiety-like behavior during adulthood indicated by reduced horizontal and vertical exploratory behaviors

Background

Fetal alcohol spectrum disorders (FASD) caused by prenatal ethanol exposure (PE) consist of many cognitive/behavioral deficits. Studies have reported that PE leads to impairments of learning and memory, attention, executive function, and anxiety. Open field (OF) is a common behavioral model which offers comprehensive ethological information. Here, we analyzed multiple parameters of OF to examine anxiety behavior and habituation after PE.

Material and Methods

Pregnant Sprague Dawley rats were gavaged twice/day with 0 or 3 g/kg/treatment ethanol (15% w/v) during gestational day (GD) 8-20, mimicking second-trimester heavy PE in humans. The control and PE adult offspring were subjected to OF task in different ambient light levels with or without acute stress.

Results

Prenatal ethanol exposure did not influence the overall locomotor activities or habituation in the OF. In lower ambient light, no PE effects could be detected. In higher ambient light, female PE rats showed less activities in the center zone, indicative of increased anxiety. Males show lower activities in the center zone only after acute stress. Rats spent <2% of the time in the center zone compared to >75% of the time in the corner zone where they engaged in frequent rearing activities (vertical exploration; exploratory rearing). Prenatal ethanol exposure led to lower rearing activities in the corner in both males and females. Acute stress masks the PE effects in males but not in females.

Discussion

The results support that heavy PE leads to persistent anxiety-like behavior during adulthood in both sexes. This conclusion is supported by using multiple parameters of exploratory behavior in the OF, including the rearing activities in the corner to reach reliable quantification of anxiety-like behavior.

Low to Moderate Prenatal Alcohol Exposure and Neurodevelopmental Outcomes: A Narrative Review and Methodological Considerations

PURPOSE

Although abstinence is recommended in pregnancy, many pregnancies are exposed to alcohol. Observational studies of the effects of low to moderate prenatal alcohol exposure (PAE) and neurodevelopmental outcomes have yielded inconsistent results, with some studies finding an increased risk of adverse neurobehavioral and cognitive outcomes, and other studies finding no changes or reduced risk of the same outcomes. The purpose of this narrative review is to summarize these inconsistencies and apply a methodological framework to discuss how different parameters contribute to the findings. The authors also provide recommendations on how to advance future research in this area.

SEARCH METHODS

The PubMed, Web of Science, and Embase databases were searched, along with reference lists of selected systematic reviews and meta-analyses. Search terms used were (infant or child or children or adolescent or offspring) AND (low or light or mild or moderate or low-to-moderate) AND (drinking or alcohol or drinks) AND (pregnancy or prenatal or fetal) AND (neurodevelopment or behavioral or psychological or cognitive or developmental) NOT (mice or rat or fish or animal) NOT (meta-analysis or review). Peer-reviewed original research studies were included if they analyzed associations between an exposure defined and characterized as low/light or moderate PAE with offspring neurodevelopmental outcomes. Animal studies, studies that did not provide clear cutoff points to classify PAE categories, studies lacking an abstinence control group, and studies that did not present a multivariable-adjusted measure of association were excluded.

SEARCH RESULTS

The searches identified 2,422 papers, with 36 papers meeting eligibility criteria. These studies were carried out across nine countries and included samples ranging from approximately 500 to 40,000 participants. Cognitive, academic, socioemotional, and behavioral outcomes were assessed from infancy through age 19.

DISCUSSION AND CONCLUSION

When the findings from the selected articles were summarized by geographic region, exposure definition, or neurodevelopmental outcome, no consistent observations or patterns emerged between low to moderate PAE and offspring outcomes. Although some studies found positive (i.e., beneficial) associations between low to moderate PAE and outcomes (primarily outcomes related to cognition) and others found negative (i.e., detrimental) associations (primarily for behavioral outcomes), most findings were null (i.e., showed no effect of PAE). The heterogeneity in study results is likely due to methodological issues, including residual confounding, effect measure modification, and exposure misclassification that make synthesis of studies difficult. Alternative study designs, including longitudinal trajectory analysis, sibling design, negative controls, and instrumental variable analyses, may reduce biases and are discussed. To date, the consequences of light to moderate levels of PAE on neurodevelopment remain unresolved; studies that advance methodological rigor will be important contributions to the field.

Latent classes of neurodevelopmental profiles and needs in children and adolescents with prenatal alcohol exposure

BACKGROUND

Fetal alcohol spectrum disorder (FASD) resulting from prenatal alcohol exposure (PAE) is a common neurodevelopmental disorder, but substantial interindividual heterogeneity complicates timely and accurate assessment, diagnosis, and intervention. The current study aimed to identify classes of children and adolescents with PAE assessed for FASD according to their pattern of significant neurodevelopmental functioning across 10 domains using latent class analysis (LCA), and to characterize these subgroups across clinical features.

METHODS

Data from the Canadian National FASD Database, a large ongoing repository of anonymized clinical data received from diagnostic clinics across Canada, was analyzed using a retrospective cross-sectional cohort design. The sample included 1440 children and adolescents ages 6 to 17 years (M = 11.0, SD = 3.5, 41.7% female) with confirmed PAE assessed for FASD between 2016 and 2020.

RESULTS

Results revealed an optimal four-class solution. The Global needs group was characterized by high overall neurodevelopmental impairment considered severe in nature. The Regulation and Cognitive needs groups presented with moderate but substantively distinguishable patterns of significant neurodevelopmental impairment. The Attention needs group was characterized by relatively low probabilities of significant neurodevelopmental impairment. Both the Global and Regulation needs groups also presented with the highest probabilities of clinical needs, further signifying potential substantive differences in assessment and intervention needs across classes.

CONCLUSIONS

Four relatively distinct subgroups were present in a large heterogeneous sample of children and adolescents with PAE assessed for FASD in Canada. These findings may inform clinical services by guiding clinicians to identify distinct service pathways for these subgroups, potentially increasing access to a more personalized treatment approach and improving outcomes.

Is 'a little' too much?: An exploration of women's beliefs about alcohol use during pregnancy

OBJECTIVE

Interventions to address alcohol use during pregnancy need to target underlying determinants of the behaviour. Using the theory of planned behaviour as a theoretical framework, the aim of this study was to identify behavioural, normative and control beliefs regarding alcohol use during pregnancy among a sample of women. Design: 435 women completed a 15-minute online questionnaire designed to identify beliefs about alcohol use during pregnancy. Data were categorised according to type of belief and then summarised and described. Results: The majority of respondents saw few advantages of consuming alcohol during pregnancy and believed that most people would disapprove of alcohol use during pregnancy. Although most women endorsed alcohol abstinence during pregnancy, views on the perceived risk of different levels of alcohol use and perceptions of the 'typical' person who drinks while pregnant varied between participants. Conclusion: This work contributes to the understanding of women's beliefs about alcohol use during pregnancy. Future research should explore how women's beliefs inform their decision making about different levels of alcohol use in pregnancy. Additionally, further research or messaging about alcohol use in pregnancy must also consider the potential for contributing to stigmatising beliefs.