Maternal prenatal anxiety and child brain-derived neurotrophic factor ( BDNF ) genotype: Effects on internalizing symptoms from 4 to 15 years of age

Genotype-environment interplay in associations between maternal drinking and offspring emotional and behavioral problems

BACKGROUND

While maternal at-risk drinking is associated with children's emotional and behavioral problems, there is a paucity of research that properly accounts for genetic confounding and gene-environment interplay. Therefore, it remains uncertain what mechanisms underlie these associations. We assess the moderation of associations between maternal at-risk drinking and childhood emotional and behavioral problems by common genetic variants linked to environmental sensitivity (genotype-by-environment [G × E] interaction) while accounting for shared genetic risk between mothers and offspring (GE correlation).

METHODS

We use data from 109 727 children born to 90 873 mothers enrolled in the Norwegian Mother, Father, and Child Cohort Study. Women self-reported alcohol consumption and reported emotional and behavioral problems when children were 1.5/3/5 years old. We included child polygenic scores (PGSs) for traits linked to environmental sensitivity as moderators.

RESULTS

Associations between maternal drinking and child emotional (β1 = 0.04 [95% confidence interval (CI) 0.03-0.05]) and behavioral (β1 = 0.07 [0.06-0.08]) outcomes attenuated after controlling for measured confounders and were almost zero when we accounted for unmeasured confounding (emotional: β1 = 0.01 [0.00-0.02]; behavioral: β1 = 0.01 [0.00-0.02]). We observed no moderation of these adjusted exposure effects by any of the PGS.

CONCLUSIONS

The lack of strong evidence for G × E interaction may indicate that the mechanism is not implicated in this kind of intergenerational association. It may also reflect insufficient power or the relatively benign nature of the exposure in this sample.

Stress and Susceptibility: A Systematic Review of Prenatal Epigenetic Risks for Developing Post-Traumatic Stress Disorder

This review aims to systematically assess the current literature about prenatal epigenetic markers that lead to post-traumatic stress disorder susceptibility across the lifespan. Studies included in this review met several research criteria: Studies included (1) participants with a PTSD diagnosis according to the DSM-5, (2) prenatal epigenetic marker data that could be analyzed, and (3) explicit references to postnatal PTSD susceptibility. Our study sample fit within a timeframe of 2002 (the earliest recorded studies of prenatal susceptibility to post-traumatic stress disorder in the databases used) and February 2021 when the literature search for this review was terminated. Studies for this review were collated from PubMed, MEDLINE, Science Direct, and Boston College School of Social Work Library databases. A systematic search was conducted in these databases using basic keyword terms, such as "PSTD resilience" and "PTSD vulnerability," and then adding clarifying terms to refine specific searches, such as "epigenetics," "genetics," "epigenetic markers," "haplotypes," and "mRNA methylation." Based on these criteria and research methods, 33 studies remained for inclusion in the review sample. This review suggests that BDNF Val66-Met, a polymorphism of FKBP5, and an altered messenger ribonucleic acid methylation marker in NR3C1 present most often in cases of PTSD. These epigenetic markers might be implicated in central neurological processes related to post-traumatic stress disorder symptomatology.

Maternal psychosocial stress during pregnancy and offspring neurobehavioral outcomes during early childhood in the Healthy Start Study

PURPOSE

We evaluate singular and combined effects of prenatal maternal depression and stress on early childhood neurobehavioral outcomes among 536 mother-child pairs.

METHODS

First, we used multivariable linear regression to investigate associations of women's Edinburgh Postnatal Depression Scale (EPDS) score and Perceived Stress Scale (PSS) score, separately, with offspring Child Behavior Checklist score. Next, to assess the combined effect of EPDS and PSS, we dichotomized each score at the fourth versus first to third quartiles and created a four-level variable comprising combinations of high and low depression and stress. Across all models, we accounted for household chaos, hubbub, and order scale (CHAOS) score, an indicator of the household environment associated with offspring behavioral outcomes.

RESULTS

Each one-unit increment in maternal EPDS and PSS scores corresponded with 0.75 (95% CI: 0.53, 0.96) and 0.72 (95% CI: 0.48, 0.95) units higher offspring total problems T-score, respectively. Children of women with high EPDS and PSS had highest T-scores for total problems. All associations remained materially unchanged after adjustment for CHAOS score.

CONCLUSIONS

Prenatal maternal depression and stress is associated with worse neurobehavioral outcomes among offspring, with the most unfavorable outcomes among children whose mothers had high scores for both EPDS and PSS.

The Association Between Prenatal Maternal Stress and Adolescent Affective Outcomes is Mediated by Childhood Maltreatment and Adolescent Behavioral Inhibition System Sensitivity

Prenatal maternal stress is linked to offspring outcomes; however, there is little research on adolescents, behavioral, transdiagnostic outcomes, or the mechanisms through which relations operate. We examined, in N = 268 adolescents (Mage = 15.31 years; SD = 1.063; 57.8% boys) whether prenatal maternal stress is associated with adolescent affective outcomes; whether this association is mediated, serially, by childhood home atmosphere and adolescent behavioral inhibition system (BIS) sensitivity; and whether mediational effects are moderated by adolescent attention-deficit/hyperactivity disorder or maternal internalizing symptomology. Prenatal maternal daily stress and major life events were associated with adolescent outcomes through childhood negative atmosphere/neglect and BIS sensitivity, with no evidence of moderation. Results have implications regarding the effect of prenatal maternal stress on offspring outcomes and regarding corresponding sensitive periods.

Psychological legacies of intergenerational trauma under South African apartheid: Prenatal stress predicts greater vulnerability to the psychological impacts of future stress exposure during late adolescence and early adulthood in Soweto, South Africa

BACKGROUND

South Africa's rates of psychiatric morbidity are among the highest in sub-Saharan Africa and are foregrounded by the country's long history of political violence during apartheid. Growing evidence suggests that in utero stress exposure is a potent developmental risk factor for future mental illness risk, yet the extent to which the psychiatric effects of prenatal stress impact the next generation are unknown. We evaluate the intergenerational effects of prenatal stress experienced during apartheid on psychiatric morbidity among children at ages 17-18 and also assess the moderating effects of maternal age, social support, and past household adversity.

METHODS

Participants come from Birth-to-Twenty, a longitudinal birth cohort study in Soweto-Johannesburg, South Africa's largest peri-urban township which was the epicentre of violent repression and resistance during the final years of the apartheid regime. Pregnant women were prospectively enrolled in 1990 and completed questionnaires assessing social experiences, and their children's psychiatric morbidity were assessed at ages 17-18.

RESULTS

Full data were available from 304 mother-child pairs in 2007-8. Maternal prenatal stress in 1990 was not directly associated greater psychiatric morbidity during at ages 17-18. Maternal age and past household adversity moderated the intergenerational mental health effects of prenatal stress such that children born to younger mothers and late adolescent/young adult children experiencing greater household adversity exhibited worse psychiatric morbidity at ages 17-18. Social support did not buffer against the long-term psychiatric impacts of prenatal stress.

CONCLUSIONS

Greater prenatal stress from apartheid predicted adverse psychiatric outcomes among children born to younger mothers and adolescents/young adults who experienced greater concurrent stress. Our findings suggest that prenatal stress may affect adolescent mental health, have stress-sensitising effects, and represent possible intergenerational effects of trauma experienced under apartheid in this sample.

Cognitive Development and Brain Gray Matter Susceptibility to Prenatal Adversities: Moderation by the Prefrontal Cortex Brain-Derived Neurotrophic Factor Gene Co-expression Network

Background: Previous studies focused on the relationship between prenatal conditions and neurodevelopmental outcomes later in life, but few have explored the interplay between gene co-expression networks and prenatal adversity conditions on cognitive development trajectories and gray matter density. Methods: We analyzed the moderation effects of an expression polygenic score (ePRS) for the Brain-derived Neurotrophic Factor gene network (BDNF ePRS) on the association between prenatal adversity and child cognitive development. A score based on genes co-expressed with the prefrontal cortex (PFC) BDNF was created, using the effect size of the association between the individual single nucleotide polymorphisms (SNP) and the BDNF expression in the PFC. Cognitive development trajectories of 157 young children from the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) cohort were assessed longitudinally in 4-time points (6, 12, 18, and 36 months) using the Bayley-II mental scales. Results: Linear mixed-effects modeling indicated that BDNF ePRS moderates the effects of prenatal adversity on cognitive growth. In children with high BDNF ePRS, higher prenatal adversity was associated with slower cognitive development in comparison with those exposed to lower prenatal adversity. Parallel-Independent Component Analysis (pICA) suggested that associations of expression-based SNPs and gray matter density significantly differed between low and high prenatal adversity groups. The brain IC included areas involved in visual association processes (Brodmann area 19 and 18), reallocation of attention, and integration of information across the supramodal cortex (Brodmann area 10). Conclusion: Cognitive development trajectories and brain gray matter seem to be influenced by the interplay of prenatal environmental conditions and the expression of an important BDNF gene network that guides the growth and plasticity of neurons and synapses.

Intersections between patient-provider communication and antenatal anxiety in a public healthcare setting in Pakistan

This study explores pregnant women’s and healthcare providers’ perspectives on the role of patient-provider communication in experiences of antenatal anxiety within a low-resource setting. In 2017–18, we consecutively sampled pregnant women (n = 19) with at least mild anxiety and purposively sampled antenatal care providers (n = 10) from a public hospital in Punjab Province, Pakistan. We then conducted in-depth interviews and thematically coded them with a combination of inductive and deductive coding methodologies. We found that patients expressed a desire for warm, empathetic communication from providers who demonstrate respect, attentiveness, and a shared lived experience. Providers revealed an awareness that their heavy caseloads, high stress levels, and discourteous tones adversely influenced communication with pregnant women and may exacerbate their anxieties, but also reported that compassionately addressing women’s concerns, providing financial problem-solving and/or assistance, and moderating conflicting healthcare desires between patients and their families could alleviate anxiety in pregnant women. Patients reported feelings of anxiety stemming from a belief that they received lower quality communication from antenatal providers at public hospitals than patients received from antenatal providers at private hospitals, an experience that they partially attributed to their low socioeconomic status. Meanwhile, some providers disclosed potentially stigmatizing views of women from particular sociocultural backgrounds or low socioeconomic status, including perceptions that appeared to shape communication with these patients in antenatal care encounters. Our findings provide preliminary evidence that communication between pregnant women and antenatal providers that is warm, normalizes patient fears, and integrates patients’ interpersonal and financial considerations can mitigate pregnant women’s experiences of anxiety and reduce barriers to accessing antenatal care in Pakistan’s public healthcare facilities.

Maternal antenatal depression and child mental health: Moderation by genomic risk for attention-deficit/hyperactivity disorder

Maternal antenatal depression strongly influences child mental health but with considerable inter-individual variation that is, in part, linked to genotype. The challenge is to effectively capture the genotypic influence. We outline a novel approach to describe genomic susceptibility to maternal antenatal depression focusing on child emotional/behavioral difficulties. Two cohorts provided measures of maternal depression, child genetic variation, and child mental health symptoms. We constructed a conventional polygenic risk score (PRS) for attention-deficit/hyperactivity disorder (ADHD) (PRSADHD) that significantly moderated the association between maternal antenatal depression and internalizing problems at 60 months (p = 2.94 × 10-4, R2 = .18). We then constructed an interaction PRS (xPRS) based on a subset of those single nucleotide polymorphisms from the PRSADHD that most accounted for the moderation of the association between maternal antenatal depression and child outcome. The interaction between maternal antenatal depression and this xPRS accounted for a larger proportion of the variance in child emotional/behavioral problems than models based on any PRSADHD (p = 5.50 × 10-9, R2 = .27), with similar findings in the replication cohort. The xPRS was significantly enriched for genes involved in neuronal development and synaptic function. Our study illustrates a novel approach to the study of genotypic moderation on the impact of maternal antenatal depression on child mental health and highlights the utility of the xPRS approach. These findings advance our understanding of individual differences in the developmental origins of mental health.

Gaining a deeper understanding of social determinants of preterm birth by integrating multi-omics data

In the US, high rates of preterm birth (PTB) and profound Black-White disparities in PTB have persisted for decades. This review focuses on the role of social determinants of health (SDH), with an emphasis on maternal stress, in PTB disparity and biological embedding. It covers: (1) PTB disparity in US Black women and possible contributors; (2) the role of SDH, highlighting maternal stress, in the persistent racial disparity of PTB; (3) epigenetics at the interface between genes and environment; (4) the role of the genome in modifying maternal stress-PTB associations; (5) recent advances in multi-omics studies of PTB; and (6) future perspectives on integrating multi-omics with SDH to elucidate the Black-White disparity in PTB. Available studies have indicated that neither environmental exposures nor genetics alone can adequately explain the Black-White PTB disparity. Preliminary yet promising findings of epigenetic and gene-environment interaction studies underscore the value of integrating SDH with multi-omics in prospective birth cohort studies, especially among high-risk Black women. In an era of rapid advancements in biomedical sciences and technologies and a growing number of prospective birth cohort studies, we have unprecedented opportunities to advance this field and finally address the long history of health disparities in PTB. IMPACT: This review provides an overview of social determinants of health (SDH) with a focus on maternal stress and its role on Black-White disparity in preterm birth (PTB). It summarizes the available literature on the interplay of maternal stress with key biological layers (e.g., individual genome and epigenome in response to environmental stressors) and significant knowledge gaps. It offers perspectives that such knowledge may provide deeper insight into how SDH affects PTB and why some women are more vulnerable than others and underscores the critical need for integrating SDH with multi-omics in prospective birth cohort studies, especially among high-risk Black women.

In-utero stress and mode of conception: impact on regulation of imprinted genes, fetal development and future health

BACKGROUND

Genomic imprinting is an epigenetic gene regulatory mechanism; disruption of this process during early embryonic development can have major consequences on both fetal and placental development. The periconceptional period and intrauterine life are crucial for determining long-term susceptibility to diseases. Treatments and procedures in assisted reproductive technologies (ART) and adverse in-utero environments may modify the methylation levels of genomic imprinting regions, including insulin-like growth factor 2 (IGF2)/H19, mesoderm-specific transcript (MEST), and paternally expressed gene 10 (PEG10), affecting the development of the fetus. ART, maternal psychological stress, and gestational exposures to chemicals are common stressors suspected to alter global epigenetic patterns including imprinted genes.

OBJECTIVE AND RATIONALE

Our objective is to highlight the effect of conception mode and maternal psychological stress on fetal development. Specifically, we monitor fetal programming, regulation of imprinted genes, fetal growth, and long-term disease risk, using the imprinted genes IGF2/H19, MEST, and PEG10 as examples. The possible role of environmental chemicals in genomic imprinting is also discussed.

SEARCH METHODS

A PubMed search of articles published mostly from 2005 to 2019 was conducted using search terms IGF2/H19, MEST, PEG10, imprinted genes, DNA methylation, gene expression, and imprinting disorders (IDs). Studies focusing on maternal prenatal stress, psychological well-being, environmental chemicals, ART, and placental/fetal development were evaluated and included in this review.

OUTCOMES

IGF2/H19, MEST, and PEG10 imprinted genes have a broad developmental effect on fetal growth and birth weight variation. Their disruption is linked to pregnancy complications, metabolic disorders, cognitive impairment, and cancer. Adverse early environment has a major impact on the developing fetus, affecting mostly growth, the structure, and subsequent function of the hypothalamic-pituitary-adrenal axis and neurodevelopment. Extensive evidence suggests that the gestational environment has an impact on epigenetic patterns including imprinting, which can lead to adverse long-term outcomes in the offspring. Environmental stressors such as maternal prenatal psychological stress have been found to associate with altered DNA methylation patterns in placenta and to affect fetal development. Studies conducted during the past decades have suggested that ART pregnancies are at a higher risk for a number of complications such as birth defects and IDs. ART procedures involve multiple steps that are conducted during critical windows for imprinting establishment and maintenance, necessitating long-term evaluation of children conceived through ART. Exposure to environmental chemicals can affect placental imprinting and fetal growth both in humans and in experimental animals. Therefore, their role in imprinting should be better elucidated, considering the ubiquitous exposure to these chemicals.

WIDER IMPLICATIONS

Dysregulation of imprinted genes is a plausible mechanism linking stressors such as maternal psychological stress, conception using ART, and chemical exposures with fetal growth. It is expected that a greater understanding of the role of imprinted genes and their regulation in fetal development will provide insights for clinical prevention and management of growth and IDs. In a broader context, evidence connecting impaired imprinted gene function to common diseases such as cancer is increasing. This implies early regulation of imprinting may enable control of long-term human health, reducing the burden of disease in the population in years to come.

Role of neurotrophins in pregnancy, delivery and postpartum

Neurotrophins (NTs) are a family of polypeptides whose functions have been extensively studied in the past two decades. In particular, Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF) play a major role in the development, nutrition and growth of the central and peripheral nervous system and in the pathogenesis of neurodegenerative, cardiometabolic and (auto)immune diseases. However, NGF and BDNF have subtle functions for follicular development, implantation, and placentation. This short narrative review summarizes the existing evidence, published between 2000 and 2019, about the role of NTs in many different conditions that might affect women during and after pregnancy such as preeclampsia, gestational diabetes, obesity, depression, anxiety, smoking and alcohol abuse. Literature suggests that the dysregulation of synthesis and release of NTs may lead to decisive effects on both maternal and fetal health. Some piece of evidences was found about a possible association between NGF/BDNF and breastfeeding. Additional studies on human models are necessary to further characterize the role of NTs in life-changing experiences like labor and delivery.

Gene-Environment Interactions in Psychiatry: Recent Evidence and Clinical Implications

PURPOSE OF REVIEW

We identify the recent evidence for gene-by-environment interaction studies in relation to psychiatric disorders. We focus on the key genotypic data as well as environmental exposures and how they interact to predict psychiatric disorders and psychiatric symptomatology. We direct our focus on the psychiatric outcomes that were focused on by the Psychiatric Genetics Consortium.

RECENT FINDINGS

Many of the studies focus on candidate gene approaches, with most of the studies drawing upon previous literature to decide the genes of interest. Other studies used a genome-wide approach. While some studies demonstrated positive replication of previous findings, replication is still an issue within gene-by-environment interaction studies. Gene-by-environment interaction research in psychiatry globally suggests some susceptibility to environmental exposures based on genotype; however, greater clarity is needed around the idea that genetic risk may not be disorder specific.

Translating basic research knowledge on the biological embedding of early-life stress into novel approaches for the developmental programming of lifelong health

This review integrates scientific knowledge obtained over the past few decades on the biological mechanisms that contribute to the profound association between exposure to early adversity, including childhood trauma and prenatal stress, and the lifelong elevated risk to develop a broad range of diseases. We further discuss insights into gene-environment interactions moderating the association between early adversity and disease manifestation and we discuss the role of epigenetic and other molecular processes in the biological embedding of early adversity. Based on these findings, we propose potential mechanisms that may contribute to the intergenerational transmission of risk related to early adversity from the mother to the fetus. Finally, we argue that basic research knowledge on the biological embedding of early adversity must now be translated into novel intervention strategies that are mechanism-driven and sensitive to developmental timing. Indeed, to date, there are no diagnostic biomarkers of risk or mechanism-informed interventions that we can offer to victims of early adversity in order to efficiently prevent or reverse adverse health outcomes. Such translational efforts can be expected to have significant impact on both clinical practice and the public health system, and will promote precision medicine in pediatrics and across the lifespan.

Fetal and Infant Outcomes in the Offspring of Parents With Perinatal Mental Disorders: Earliest Influences

Mental illness is highly prevalent and runs in families. Mental disorders are considered to enhance the risk for the development of psychopathology in the offspring. This heightened risk is related to the separate and joint effects of inherited genetic vulnerabilities for psychopathology and environmental influences. The early years of life are suggested to be a key developmental phase in the intergenerational psychopathology transmission. Available evidence supports the idea that early exposure to parental psychopathology, during the pregnancy and first postpartum year, may be related to child psychological functioning beyond the postpartum period, up to adulthood years. This not only highlights the importance of intervening early to break the chain of intergenerational transmission of psychopathology but also raises the question of whether early interventions targeting parental mental disorders in this period may alleviate these prolonged adverse effects in the infant offspring. The current article focuses on the specific risk of psychopathology conveyed from mentally ill parents to the offspring during the pregnancy and first postpartum year. We first present a summary of the available evidence on the associations of parental perinatal mental illness with infant psychological outcomes at the behavioral, biological, and neurophysiological levels. Next, we address the effects of early interventions and discuss whether these may mitigate the early intergenerational transmission of risk for psychopathology. The summarized evidence supports the idea that psychopathology-related changes in parents' behavior and physiology in the perinatal period are related to behavioral, biological, and neurophysiological correlates of infant psychological functioning in this period. These alterations may constitute risk for later development of child and/or adult forms of psychopathology and thus for intergenerational transmission. Targeting psychopathology or mother-infant interactions in isolation in the postnatal period may not be sufficient to improve outcomes, whereas interventions targeting both maternal psychopathology and mother-infant interactions seem promising in alleviating the risk of early transmission.

Impact of Maternal Perinatal Anxiety on Social-Emotional Development of 2-Year-Olds, A Prospective Study of Norwegian Mothers and Their Offspring : The Impact of Perinatal Anxiety on Child Development

Introduction Anxiety in women is highly prevalent during pregnancy and in the postnatal period. Anxiety disorders in mothers have been linked to adverse outcomes in their children's development. However, large-scale prospective studies on this issue, covering both the prenatal and postnatal period with follow-up periods beyond the first year of life are scarce. Method In this prospective cohort study, data gathered from 1336 Norwegian women and their children were used. Maternal anxiety symptoms were measured at gestation week 17-19 and 32, as well as 8 weeks postpartum using the Symptom Check List. Child development problems were assessed at 2 years postpartum using the Ages & Stages Questionnaire: Social-Emotional. Logistic regressions were conducted to examine the association between maternal prenatal, postnatal, and perinatal anxiety and the risk of social-emotional development problems in 2-year-old children. Results Of all women, 8.2% experienced prenatal anxiety, 4.0% had postnatal anxiety, and 4.4% reported perinatal anxiety (i.e., anxiety in both the prenatal and postnatal period). 5.6% of the 2-year-olds showed problems in their social-emotional behavior. Child development problems were associated with maternal prenatal anxiety (Odds Ratio [OR] = 2.48, 95% CI 1.55-4.92), postnatal anxiety (OR 3.32, 95% CI 1.43-7.74), and anxiety both in the prenatal and postnatal period (OR 3.98, 95% CI 1.85-8.56). Adjusted for confounders, maternal anxiety continued to be a significant predictor of adverse child social-emotional development (postnatal anxiety: OR 2.46, 95% CI 1.01-5.97; perinatal anxiety: OR 2.40, 95% CI 1.03-5.59). Discussion Maternal postnatal anxiety and anxiety both during and after pregnancy are unique substantial predictors for problems in a 2-year-old's social-emotional development, even when controlled for confounders.

Prenatal Maternal Distress: A Risk Factor for Child Anxiety?

The deleterious association between various types of prenatal maternal psychological distress (PNMS, anxiety, depression, psychological distress, stress) and childhood anxiety symptomatology (internalizing behaviors, anxiety symptoms) has been established using both retrospective and prospective longitudinal studies across varied demographic cohorts and throughout development. Yet, the existing literature cannot claim maternal distress during pregnancy to be a specific risk factor for anxiety symptomatology, as studies utilizing such observational designs are unable to adequately account for confounding of potential genetic factors and the postnatal environment. In this review, we examine studies that attempt to minimize such confounding and thus disentangle the unique intrauterine exposure effect of varying types of PNMS on childhood anxiety symptomatology. Such methodologies include paternal versus maternal comparison studies, sibling comparisons, prenatal cross-fostering designs and timing of exposure studies (including disaster studies). Of the identified studies, findings indicate that prenatal maternal distress is likely to constitute a risk factor for anxiety symptomatology, although more studies are needed to replicate current findings in order to determine whether there are clear differences in effects across specific types of PNMS and for specific subpopulations. We review the methodological limitations and strengths of the literature prior to exploring avenues of future research and implications for theory and clinical practice.

The early care environment and DNA methylome variation in childhood

Prenatal adversity shapes child neurodevelopment and risk for later mental health problems. The quality of the early care environment can buffer some of the negative effects of prenatal adversity on child development. Retrospective studies, in adult samples, highlight epigenetic modifications as sentinel markers of the quality of the early care environment; however, comparable data from pediatric cohorts are lacking. Participants were drawn from the Maternal Adversity Vulnerability and Neurodevelopment (MAVAN) study, a longitudinal cohort with measures of infant attachment, infant development, and child mental health. Children provided buccal epithelial samples (mean age = 6.99, SD = 1.33 years, n = 226), which were used for analyses of genome-wide DNA methylation and genetic variation. We used a series of linear models to describe the association between infant attachment and (a) measures of child outcome and (b) DNA methylation across the genome. Paired genetic data was used to determine the genetic contribution to DNA methylation at attachment-associated sites. Infant attachment style was associated with infant cognitive development (Mental Development Index) and behavior (Behavior Rating Scale) assessed with the Bayley Scales of Infant Development at 36 months. Infant attachment style moderated the effects of prenatal adversity on Behavior Rating Scale scores at 36 months. Infant attachment was also significantly associated with a principal component that accounted for 11.9% of the variation in genome-wide DNA methylation. These effects were most apparent when comparing children with a secure versus a disorganized attachment style and most pronounced in females. The availability of paired genetic data revealed that DNA methylation at approximately half of all infant attachment-associated sites was best explained by considering both infant attachment and child genetic variation. This study provides further evidence that infant attachment can buffer some of the negative effects of early adversity on measures of infant behavior. We also highlight the interplay between infant attachment and child genotype in shaping variation in DNA methylation. Such findings provide preliminary evidence for a molecular signature of infant attachment and may help inform attachment-focused early intervention programs.

Prenatal maternal stress, fetal programming, and mechanisms underlying later psychopathology-A global perspective

There is clear evidence that the mother's stress, anxiety, or depression during pregnancy can alter the development of her fetus and her child, with an increased risk for later psychopathology. We are starting to understand some of the underlying mechanisms including the role of the placenta, gene-environment interactions, epigenetics, and specific systems including the hypothalamic-pituitary-adrenal axis and cytokines. In this review we also consider how these effects may be different, and potentially exacerbated, in different parts of the world. There can be many reasons for elevated prenatal stress, as in communities at war. There may be raised pregnancy-specific anxiety with high levels of maternal and infant death. There can be raised interpersonal violence (in Afghanistan 90.2% of women thought that "wife beating" was justified compared with 2.0% in Argentina). There may be interactions with nutritional deficiencies or with extremes of temperature. Prenatal stress alters the microbiome, and this can differ in different countries. Genetic differences in different ethnic groups may make some more vulnerable or more resilient to the effects of prenatal stress on child neurodevelopment. Most research on these questions has been in predominantly Caucasian samples from high-income countries. It is now time to understand more about prenatal stress and psychopathology, and the role of both social and biological differences, in the rest of the world.

Prenatal Immune and Endocrine Modulators of Offspring's Brain Development and Cognitive Functions Later in Life

Milestones of brain development in mammals are completed before birth, which provide the prerequisite for cognitive and intellectual performances of the offspring. Prenatal challenges, such as maternal stress experience or infections, have been linked to impaired cognitive development, poor intellectual performances as well as neurodevelopmental and psychiatric disorders in the offspring later in life. Fetal microglial cells may be the target of such challenges and could be functionally modified by maternal markers. Maternal markers can cross the placenta and reach the fetus, a phenomenon commonly referred to as “vertical transfer.” These maternal markers include hormones, such as glucocorticoids, and also maternal immune cells and cytokines, all of which can be altered in response to prenatal challenges. Whilst it is difficult to discriminate between the maternal or fetal origin of glucocorticoids and cytokines in the offspring, immune cells of maternal origin—although low in frequency—can be clearly set apart from offspring's cells in the fetal and adult brain. To date, insights into the functional role of these cells are limited, but it is emergingly recognized that these maternal microchimeric cells may affect fetal brain development, as well as post-natal cognitive performances and behavior. Moreover, the inheritance of vertically transferred cells across generations has been proposed, yielding to the presence of a microchiome in individuals. Hence, it will be one of the scientific challenges in the field of neuroimmunology to identify the functional role of maternal microchimeric cells as well as the brain microchiome. Maternal microchimeric cells, along with hormones and cytokines, may induce epigenetic changes in the fetal brain. Recent data underpin that brain development in response to prenatal stress challenges can be altered across several generations, independent of a genetic predisposition, supporting an epigenetic inheritance. We here discuss how fetal brain development and offspring's cognitive functions later in life is modulated in the turnstile of prenatal challenges by introducing novel and recently emerging pathway, involving maternal hormones and immune markers.

Prenatal intimate partner violence exposure predicts infant biobehavioral regulation: Moderation by the brain-derived neurotrophic factor (BDNF) gene

The ability to regulate stress is a critical developmental milestone of early childhood that involves a set of interconnected behavioral and physiological processes and is influenced by genetic and environmental stimuli. Prenatal exposure to traumatic stress and trauma, including intimate partner violence (IPV), increases risk for offspring biobehavioral regulation problems during childhood and adolescence. Although individual differences in susceptibility to prenatal stress have been largely unexplored, a handful of studies suggest children with specific genetic characteristics are most vulnerable to prenatal stress. We evaluated the brain-derived neurotrophic factor Val66Met gene (BDNF) as a moderator of the effect of prenatal IPV exposure on infant temperamental and cortisol regulation in response to a psychosocial challenge. Ninety-nine mother–infant dyads recruited from the community were assessed when infants (51% female) were 11 to 14 months. Maternal reports of IPV during pregnancy and infant temperament were obtained, and infant saliva was collected for genotyping and to assess cortisol reactivity (before and after the Strange Situation Task). Significant genetic moderation effects were found. Among infants with the BDNF Met allele, prenatal IPV predicted worse temperamental regulation and mobilization of the cortisol response, while controlling for infant postnatal exposure to IPV, other maternal traumatic experiences, and infant sex. However, prenatal IPV exposure was not associated with temperamental or cortisol outcomes among infant carriers of the Val/Val genotype. Findings are discussed in relation to prenatal programming and biological susceptibility to stress.

Prenatal stress and genetic risk: How prenatal stress interacts with genetics to alter risk for psychiatric illness

Risk for neuropsychiatric disorders is complex and includes an individual's internal genetic endowment and their environmental experiences and exposures. Embryonic development captures a particularly complex period, in which genetic and environmental factors can interact to contribute to risk. These environmental factors are incorporated differently into the embryonic brain than postnatal one. Here, we comprehensively review the human and animal model literature for studies that assess the interaction between genetic risks and one particular environmental exposure with strong and complex associations with neuropsychiatric outcomes-prenatal maternal stress. Gene-environment interaction has been demonstrated for stress occurring during childhood, adolescence, and adulthood. Additional work demonstrates that prenatal stress risk may be similarly complex. Animal model studies have begun to address some underlying mechanisms, including particular maternal or fetal genetic susceptibilities that interact with stress exposure and those that do not. More specifically, the genetic underpinnings of serotonin and dopamine signaling and stress physiology mechanisms have been shown to be particularly relevant to social, attentional, and internalizing behavioral changes, while other genetic factors have not, including some growth factor and hormone-related genes. Interactions have reflected both the diathesis-stress and differential susceptibility models. Maternal genetic factors have received less attention than those in offspring, but strongly modulate impacts of prenatal stress. Priorities for future research are investigating maternal response to distinct forms of stress and developing whole-genome methods to examine the contributions of genetic variants of both mothers and offspring, particularly including genes involved in neurodevelopment. This is a burgeoning field of research that will ultimately contribute not only to a broad understanding of psychiatric pathophysiology but also to efforts for personalized medicine.

Prenatal Stress, Glucocorticoids, and Developmental Programming of the Stress Response

The early environment has a major impact on the developing embryo, fetus, and infant. Parental adversity (maternal and paternal) and glucocorticoid exposure before conception and during pregnancy have profound effects on the development and subsequent function of the hypothalamic-pituitary-adrenal axis and related behaviors. These effects are species-, sex-, and age-specific and depend on the timing and duration of exposure. The impact of these early exposures can extend across multiple generations, via both the maternal and paternal lineage, and recent studies have begun to determine the mechanisms by which this occurs. Improved knowledge of the mechanisms by which adversity and glucocorticoids program stress systems will allow development of strategies to ameliorate and/or reverse these long-term effects.

Prenatal anxiety effects: A review

This review is based on literature on prenatal anxiety effects that was found on Pubmed and PsycINFO for the years 2010-2016. Prenatal anxiety is thought to have distinct features, although it has been measured both by specific prenatal anxiety symptoms as well as by standardized anxiety scales. Its prevalence has ranged from 21 to 25% and it has been predicted by a number of pregnancy - related variables such as unintended pregnancy, demographic variables such as low acculturation and income and psychosocial factors including pessimism and partner tension. Prenatal anxiety effects on pregnancy include increased cortisol levels, pro-inflammatory cytokines, obstetric problems and cesarean section. Effects on the neonate include lower gestational age, prematurity, less insulin-like growth factor in cord blood, less exclusive breast-feeding and less self-regulation during the heelstick procedure. Prenatal anxiety effects continue into infancy and childhood both on physiological development and emotional/mental development. Among the physiological effects are lower vagal activity across the first two years, and lower immunity, more illnesses and reduced gray matter in childhood. Prenatal anxiety effects on emotional/mental development include greater negative emotionality and in infants, lower mental development scores and internalizing problems. Anxiety disorders occur during childhood and elevated cortisol and internalizing behaviors occur during adolescence. Interventions for prenatal anxiety are virtually nonexistent, although stroking (massaging) the infant has moderated the pregnancy - specific anxiety effects on internalizing behaviors in the offspring. The limitations of this literature include the homogeneity of samples, the frequent use of anxiety measures that are not specific to pregnancy, and the reliance on self-report. Nonetheless, the literature highlights the negative, long-term effects of prenatal anxiety and the need for screening and early interventions.

Maternal prenatal anxiety and child COMT genotype predict working memory and symptoms of ADHD

Maternal prenatal anxiety is an important risk factor for altered child neurodevelopment but there is uncertainty concerning the biological mechanisms involved and sources of individual differences in children's responses. We sought to determine the role of functional genetic variation in COMT, which encodes catechol-O-methyltransferase, in the association between maternal prenatal anxiety and child symptoms of ADHD and working memory. We used the prospectively-designed ALSPAC cohort (n = 6,969) for our primary data analyses followed by replication analyses in the PREDO cohort (n = 425). Maternal prenatal anxiety was based on self-report measures; child symptoms of ADHD were collected from 4-15 years of age; working memory was assessed from in-person testing at age 8 years; and genetic variation in COMT at rs4680 was determined in both mothers and children. The association between maternal prenatal anxiety and child attention/hyperactivity symptoms and working memory was moderated by the child's rs4680 genotype, with stronger effects obtained for the val/val (G:G) genotype relative to val/met (A:G) (all p<0.01) and met/met (A:A) groups (all p<0.05). Similar findings were observed in the PREDO cohort where maternal prenatal anxiety interacted with child rs4680 to predict symptoms of ADHD at 3.5 years of age. The findings, from two cohorts, show a robust gene-environment interaction, which may contribute to inter-individual differences in the effects of maternal prenatal anxiety on developmental outcomes from childhood to mid-adolescence.

Prenatal parenting

Parenting begins before birth. This includes prenatal maternal and paternal bonding with the baby, and biological effects on fetal development. Recent research has confirmed how prenatal maternal stress can alter the development of the fetus and the child, and that this can persist until early adulthood. Children are affected in different ways depending, in part, on their own genetic makeup. The fetus may also have a direct effect on prenatal maternal mood and later parenting behaviour via the placenta. The father is important prenatally too. An abusive partner can increase the mother's prenatal stress and alter fetal development, but he can also be an important source of emotional support. New research suggests the potential benefits of prenatal interventions, including viewing of prenatal scans and cognitive behavioural therapy.

Serum brain-derived neurotrophic factor (BDNF) across pregnancy and postpartum: Associations with race, depressive symptoms, and low birth weight

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is implicated as a causal factor in major depression and is critical to placental development during pregnancy. Longitudinal data on BDNF across the perinatal period are lacking. These data are of interest given the potential implications for maternal mood and fetal growth, particularly among Black women who show ∼2-fold greater risk for delivering low birth weight infants.

METHODS

Serum BDNF, serum cortisol, and depressive symptoms (per CES-D) were assessed during each trimester and 4-11 weeks postpartum among 139 women (77 Black, 62 White). Low birth weight (<2500g) was determined via medical record.

RESULTS

Serum BDNF declined considerably from 1st through 3rd trimesters (ps≤0.008) and subsequently increased at postpartum (p<0.001). Black women exhibited significantly higher serum BDNF during the 1st trimester, 2nd trimester, and postpartum (ps≤0.032) as well as lower serum cortisol during the 2nd and 3rd trimester (ps≤0.01). Higher serum cortisol was concurrently associated with lower serum BDNF in the 2nd trimester only (p<0.05). Controlling for race, serum BDNF at both the 2nd and 3rd trimester was negatively associated with 3rd trimester depressive symptoms (ps≤0.02). In addition, women delivering low versus healthy weight infants showed significantly lower serum BDNF in the 3rd trimester (p=0.004). Women delivering low versus healthy weight infants did not differ in depressive symptoms at any time point during pregnancy (ps≥0.34).

CONCLUSIONS

Serum BDNF declines considerably across pregnancy in Black and White women, with overall higher levels in Blacks. Lower serum BDNF in late pregnancy corresponds with higher depressive symptoms and risk for low birth weight in Black and White women. However, the predictive value of serum BDNF in pregnancy is specific to within-race comparisons. Potential links between racial differences in serum BDNF and differential pregnancy-related cortisol adaptation require further investigation.

Influence of prenatal maternal stress on umbilical cord blood cytokine levels

PURPOSE

Prenatal maternal stress (PNMS) is known to influence fetal programming and development. Thus far, the effects of PNMS on the developing immune system have mainly been documented in animal studies. This study aimed to examine the association between PNMS and immune cytokine profiles in the umbilical cord blood of newborn human infants.

METHODS

PNMS, including perceived stress, numbers of stressful life events experiences (both partner and health related), and state and trait anxiety, was assessed with five questionnaires and interviews from 43 pregnant women during the second trimester. Seven key cytokines important for immune function, i.e., IL-12, IL-1β, IL-4, IL-5, IL-6, IL-8, and TNF-α, were analyzed in cord blood by bead-based ELISA method (Luminex 200). Logistic regression was used to estimate the associations of PNMS scores and cytokine levels.

RESULTS

Increased levels of IL-1β, IL-4, IL-5, IL-6, and IL-8 were significantly associated with at least one of the maternal stress assessments, while the levels of IL-12 and TNF-α were not significantly associated with any of the PNMS measurements examined.

CONCLUSION

These preliminary findings suggest that PNMS may influence cytokine levels in newborn infants, in particular Th2-related cytokines. This report supports previous findings in animal studies and could suggest that newborns born to mothers with elevated PNMS have a predisposition to immune-related disorders.

Maternal depression and mental health in early childhood: an examination of underlying mechanisms in low-income and middle-income countries

Studies examining mechanisms underlying associations between maternal depression and adverse child outcomes (including behaviour, socioemotional adjustment, and emotion regulation) indicate that during pregnancy, maternal depression could affect child outcomes through altered placental function, epigenetic changes in the child, and stress reactivity. Infection and dietary deficiencies in the mother and the child, together with the child's genetic vulnerability, might also affect outcome. Postnatally, associations between maternal depression and child outcome are influenced by altered mother-child interactions, sociodemographic or environmental influences, and social support. Knowledge is scarce on mechanisms in low-income and middle-income countries where maternal depression is highly prevalent, and stressful factors that influence the development of perinatal maternal depression and adverse child outcome (eg, food insecurity, perinatal infections, crowded or rural living conditions, and interpersonal violence) are both more intense and more common than in high-income countries. We reviewed evidence and use the biopsychosocial model to illustrate risk factors, mediators and moderators underlying associations between maternal depression and child outcomes in low-income and middle-income countries.

A Role for the Placenta in Programming Maternal Mood and Childhood Behavioural Disorders

Substantial data demonstrate that the early-life environment, including in utero, plays a key role in later life disease. In particular, maternal stress during pregnancy has been linked to adverse behavioural and emotional outcomes in children. Data from human cohort studies and experimental animal models suggest that modulation of the developing epigenome in the foetus by maternal stress may contribute to the foetal programming of disease. Here, we summarise insights gained from recent studies that may advance our understanding of the role of the placenta in mediating the association between maternal mood disorders and offspring outcomes. First, the placenta provides a record of exposures during pregnancy, as indicated by changes in the placental trancriptome and epigenome. Second, prenatal maternal mood may alter placental function to adversely impact foetal and child development. Finally, we discuss the less well established but interesting possibility that altered placental function, more specifically changes in placental hormones, may adversely affect maternal mood and later maternal behaviour, which can also have consequence for offspring well-being.

Maternal Affective Illness in the Perinatal Period and Child Development: Findings on Developmental Timing, Mechanisms, and Intervention

Maternal mental illness is one of the most reliable risks for clinically significant child adjustment difficulties. The research literature in this area is very large and broad and dates back decades. In this review, we consider recent research findings on maternal mental illness and child development by focusing particularly on affective illness the perinatal period. We do this because maternal affective illness in the perinatal period is common; recent evidence suggests that pre- and postpartum maternal depression may have lasting effects on child behavioral and somatic health; research in the perinatal period raises acute and compelling questions about mechanisms of transmission and effect; and perinatal-focused interventions may offer distinct advantages for benefitting mother and child and gaining insights into developmental mechanisms. Throughout the review, we attend to the increasing integration of psychological and biological models and the trans-disciplinary approach now required for clinical investigation.

Long-term effects of early life stress exposure: Role of epigenetic mechanisms

Stress is an adaptive response to demands of the environment and thus essential for survival. Exposure to stress during the first years of life has been shown to have profound effects on the growth and development of an adult individual. There are evidences demonstrating that stressful experiences during gestation or in early life can lead to enhanced susceptibility to mental disorders. Early-life stress triggers hypothalamic-pituitary-adrenocortical (HPA) axis activation and the associated neurochemical reactions following glucocorticoid release are accompanied by a rapid physiological response. An excessive response may affect the developing brain resulting in neurobehavioral and neurochemical changes later in life. This article reviews the data from experimental studies aimed to investigate hormonal, functional, molecular and epigenetic mechanisms involved in the stress response during early-life programming. We think these studies might prove useful for the identification of novel pharmacological targets for more effective treatments of mental disorders.

Associations of maternal and paternal antenatal mood with offspring anxiety disorder at age 18 years

OBJECTIVE

Maternal antenatal depression and anxiety are associated with increased risk of childhood behavioural and emotional problems in offspring; it remains unclear to what extent this is due to a maternal biological impact on foetal development. Here, we compare associations between maternal and paternal antenatal depression and anxiety with offspring anxiety disorders, thus controlling for some genetic and shared environmental factors.

METHODS

We used data from the ALSPAC population cohort including measures of antenatal parental depression and anxiety. At 18 years, offspring completed the CIS-R interview, yielding diagnoses for anxiety disorders. Results were adjusted for confounding variables including parental postnatal depression and anxiety.

RESULTS

Children of women with antenatal depression (18 weeks gestation), had an increased risk of anxiety disorders at 18 years of age (11.1% vs. 6.2%; adj. OR 1.75 (1.19, 2.58); p=0.01). Children of women with antenatal anxiety had increased risk of co-morbid anxiety and depression (adj. OR 1.39 (1.06, 1.82); p=0.02). No such associations were found with paternal antenatal depression or anxiety.

LIMITATIONS

There was a high attrition rate from the original cohort to the CIS-R completion at 18 years postpartum. Parental mood was only assessed together at one time point during the antenatal period.

CONCLUSIONS

The differences in the association between maternal and paternal mood during pregnancy and child outcomes supports the hypothesis that foetal programming may account, at least in part, for this association. We highlight the potential opportunity for preventative intervention by optimising antenatal mental health.