Association Between Maternal Adverse Childhood Experiences and Neonatal SCG5 DNA Methylation-Effect Modification by Prenatal Home Visiting

Epigenetic Responses to Nonchemical Stressors: Potential Molecular Links to Perinatal Health Outcomes

PURPOSE OF REVIEW

We summarize the recent literature investigating exposure to four nonchemical stressors (financial stress, racism, psychosocial stress, and trauma) and DNA methylation, miRNA expression, and mRNA expression. We also highlight the relationships between these epigenetic changes and six critical perinatal outcomes (preterm birth, low birth weight, preeclampsia, gestational diabetes, childhood allergic disease, and childhood neurocognition).

RECENT FINDINGS

Multiple studies have found financial stress, psychosocial stress, and trauma to be associated with DNA methylation and/or miRNA and mRNA expression. Fewer studies have investigated the effects of racism. The majority of studies assessed epigenetic or genomic changes in maternal blood, cord blood, or placenta. Several studies included multi-OMIC assessments in which DNA methylation and/or miRNA expression were associated with gene expression. There is strong evidence for the role of epigenetics in driving the health outcomes considered. A total of 22 biomarkers, including numerous HPA axis genes, were identified to be epigenetically altered by both stressors and outcomes. Epigenetic changes related to inflammation, the immune and endocrine systems, and cell growth and survival were highlighted across numerous studies. Maternal exposure to nonchemical stressors is associated with epigenetic and/or genomic changes in a tissue-specific manner among inflammatory, immune, endocrine, and cell growth-related pathways, which may act as mediating pathways to perinatal health outcomes. Future research can test the mediating role of the specific biomarkers identified as linked with both stressors and outcomes. Understanding underlying epigenetic mechanisms altered by nonchemical stressors can provide a better understanding of how chemical and nonchemical exposures interact.

Effect of parental adverse childhood experiences on intergenerational DNA methylation signatures from peripheral blood mononuclear cells and buccal mucosa

In this study, the effect of cumulative ACEs experienced on human maternal DNA methylation (DNAm) was estimated while accounting for interaction with domains of ACEs in prenatal peripheral blood mononuclear cell samples from the Maternal and Developmental Risks from Environmental Stressors (MADRES) pregnancy cohort. The intergenerational transmission of ACE-associated DNAm was also explored used paired maternal (N = 120) and neonatal cord blood (N = 69) samples. Replication in buccal samples was explored in the Children's Health Study (CHS) among adult parental (N = 31) and pediatric (N = 114) samples. We used a four-level categorical indicator variable for ACEs exposure: none (0 ACEs), low (1-3 ACEs), moderate (4-6 ACEs), and high (>6 ACEs). Effects of ACEs on maternal DNAm (N = 240) were estimated using linear models. To evaluate evidence for intergenerational transmission, mediation analysis (N = 60 mother-child pairs) was used. Analysis of maternal samples displayed some shared but mostly distinct effects of ACEs on DNAm across low, moderate, and high ACEs categories. CLCN7 and PTPRN2 was associated with maternal DNAm in the low ACE group and this association replicated in the CHS. CLCN7 was also nominally significant in the gene expression correlation analysis among maternal profiles (N = 35), along with 11 other genes. ACE-associated methylation was observed in maternal and neonatal profiles in the COMT promoter region, with some evidence of mediation by maternal COMT methylation. Specific genomic loci exhibited mutually exclusive maternal ACE effects on DNAm in either maternal or neonatal population. There is some evidence for an intergenerational effect of ACEs, supported by shared DNAm signatures in the COMT gene across maternal-neonatal paired samples.

Maternal Childhood Adversity and Infant Epigenetic Aging: Moderation by Restless Sleep During Pregnancy

Maternal exposure to childhood adversity is associated with detrimental health outcomes throughout the lifespan and may have implications for offspring. Evidence links maternal adverse childhood experiences (ACEs) to detrimental birth outcomes, yet the impact on the infant's epigenome is unclear. Moreover, maternal sleep habits during pregnancy may influence this association. Here, we explore whether restless sleep during pregnancy moderates the association between exposure to maternal childhood adversity and infant epigenetic age acceleration in 332 mother-infant dyads (56% female; 39% Black; 25% Hispanic). During the 2nd trimester, mothers self-reported childhood adversity and past-week restless sleep; DNA methylation from umbilical vein endothelial cells was used to estimate five epigenetic clocks. Multivariable linear regression was used to test study hypotheses. Despite no evidence of main effects, there was evidence of an interaction between maternal ACEs and restless sleep in predicting infant epigenetic age acceleration using the EPIC Gestational Age clock. Only infants whose mothers reported exposure to both ACEs and restless sleep demonstrated accelerated epigenetic aging. Results provide preliminary evidence that maternal childhood adversity and sleep may influence the infant epigenome.

Intergenerational Transmission of Parental Adverse Childhood Experiences and Children's Outcomes: A Scoping Review

Adverse childhood experiences (ACEs) are among the leading environmental causes of morbidity and mortality. Extending research on within-generation effects, more recent scholarship has explored between-generation consequences of ACEs. Despite growing interest in the intergenerational effects of parents' ACEs on children's outcomes, this line of scholarship has yet to be coalesced into a comprehensive review. The current study is a scoping review on the intergenerational transmission of parental ACEs and children's outcomes. Ten databases such as PubMed, APA PsycArticles, and Social Work Abstracts were searched. To be included, empirical studies must have been published in English and analyzed associations between a cumulative measure of at least four parental ACEs and children's outcomes. Sixty-eight studies qualified for the review and, among these, 60 were published in the most recent 5 years (2018-2022). Fifty-one studies had sample sizes smaller than 500, and 55 focused on the effect of maternal ACEs. Nearly all studies demonstrated that parental ACEs could affect children's outcomes directly or indirectly via mechanisms like maternal mental health problems or parenting-related factors. By scoping the extant literature, this review advances the knowledge base regarding the intergenerational impacts of parental childhood trauma and children's outcomes. It also reveals methodological limitations that should be addressed in future research to strengthen causal inferences along with practical implications for interventions that aim to interrupt the intergenerational transmission of trauma.

Maternal adverse childhood experiences (ACEs) and DNA methylation of newborns in cord blood

BACKGROUND

Adverse childhood experiences (ACEs) increase the risk of poor health outcomes later in life. Psychosocial stressors may also have intergenerational health effects by which parental ACEs are associated with mental and physical health of children. Epigenetic programming may be one mechanism linking parental ACEs to child health. This study aimed to investigate epigenome-wide associations of maternal preconception ACEs with DNA methylation patterns of children. In the Center for the Health Assessment of Mothers and Children of Salinas study, cord blood DNA methylation was measured using the Illumina HumanMethylation450 BeadChip. Preconception ACEs, which occurred during the mothers' childhoods, were collected using a standard ACE questionnaire including 10 ACE indicators. Maternal ACE exposures were defined in this study as (1) the total number of ACEs; (2) the total number of ACEs categorized as 0, 1-3, and > 4; and (3) individual ACEs. Associations of ACE exposures with differential methylated positions, regions, and CpG modules determined using weighted gene co-expression network analysis were evaluated adjusting for covariates.

RESULTS

Data on maternal ACEs and cord blood DNA methylation were available for 196 mother/newborn pairs. One differential methylated position was associated with maternal experience of emotional abuse (cg05486260/FAM135B gene; q value < 0.05). Five differential methylated regions were significantly associated with the total number of ACEs, and 36 unique differential methylated regions were associated with individual ACEs (Šidák p value < 0.05). Fifteen CpG modules were significantly correlated with the total number of ACEs or individual ACEs, of which 8 remained significant in fully adjusted models (p value < 0.05). Significant modules were enriched for pathways related to neurological and immune development and function.

CONCLUSIONS

Maternal ACEs prior to conception were associated with cord blood DNA methylation of offspring at birth. Although there was limited overlap between differential methylated regions and CpGs in modules associated with ACE exposures, statistically significant regions and networks were related to genes involved in neurological and immune function. Findings may provide insights to pathways linking psychosocial stressors to health. Further research is needed to understand the relationship between changes in DNA methylation and child health.

Exploring perinatal biopsychosocial factors and epigenetic age in 1-year-old offspring

Background: Little is known about the determinants of epigenetic aging in pediatric populations. Methods: Epigenetic age was estimated from 258 1-year-olds, using pediatric buccal epigenetic and Horvath clocks. We explored associations between epigenetic age and maternal indicators of mental and relational health, substance use and general physical health assessed during trimester three. Results: Higher anxiety and stress, BMI and higher parent-parent relationship quality were associated with pediatric buccal epigenetic clock differences. High blood pressure during pregnancy was associated with Horvath age acceleration. Third-trimester smoking and pre-pregnancy weight were associated with acceleration and deceleration respectively, and concordant across clocks. Conclusion: A broad range of maternal factors may shape epigenetic age in infancy; further research is needed to explore the possible effects on health and development.

Biological Embedding of Early-Life Adversity and a Scoping Review of the Evidence for Intergenerational Epigenetic Transmission of Stress and Trauma in Humans

Severe or chronic stress and trauma can have a detrimental impact on health. Evidence suggests that early-life adversity can become biologically embedded and has the potential to influence health outcomes decades later. Epigenetics is one mechanism that has been implicated in these long-lasting effects. Observational studies in humans indicate that the effects of stress could even persist across generations, although whether or not epigenetic mechanisms are involved remains under debate. Here, we provide an overview of studies in animals and humans that demonstrate the effects of early-life stress on DNA methylation, one of the most widely studied epigenetic mechanisms, and summarize findings from animal models demonstrating the involvement of epigenetics in the transmission of stress across generations. We then describe the results of a scoping review to determine the extent to which the terms intergenerational or transgenerational have been used in human studies investigating the transmission of trauma and stress via epigenetic mechanisms. We end with a discussion of key areas for future research to advance understanding of the role of epigenetics in the legacy effects of stress and trauma.

Effect of Parental Adverse Childhood Experiences on Intergenerational DNA Methylation Signatures

Adverse Childhood Experiences (ACEs) are events that occur before a child turns 18 years old that may cause trauma. In this study, the effect of cumulative ACEs experienced on human maternal DNA methylation (DNAm) was estimated while accounting for interaction with domains of ACEs in prenatal peripheral blood mononuclear cell samples from the Maternal and Developmental Risks from Environmental Stressors (MADRES) pregnancy cohort. The intergenerational transmission of ACE-associated DNAm was also explored used paired maternal and neonatal cord blood samples. Replication in buccal samples was explored in the Children's Health Study (CHS). We used a four-level categorical indicator variable for ACEs exposure: none (0 ACEs), low (1-3 ACEs), moderate (4-6 ACEs), and high (> 6 ACEs). Effects of ACEs on maternal DNAm (N = 240) were estimated using linear models. To evaluate evidence for intergenerational transmission, mediation analysis was used. Analysis of maternal samples displayed some shared but mostly distinct effects of ACEs on DNAm across low, moderate, and high ACEs categories. CLCN7 and PTPRN2 was associated with maternal DNAm in the low ACE group and this association replicated in the CHS. ACE-associated methylation was observed in maternal and neonatal profiles in the COMT promoter region, with some evidence of mediation by maternal COMT methylation. Specific genomic loci exhibited mutually exclusive maternal ACE effects on DNAm in either maternal or neonatal population. There is some evidence for an intergenerational effect of ACEs, supported by shared DNAm signatures in the COMT gene across maternal-neonatal paired samples.

Maternal Mental Health and Offspring Brain Development: An Umbrella Review of Prenatal Interventions

The idea that risk for psychiatric disorders may be transmitted intergenerationally via prenatal programming places interest in the prenatal period as a critical moment during which intervention efforts may have a strong impact, yet studies testing whether prenatal interventions also protect offspring are limited. The present umbrella review of systematic reviews and meta-analyses (SRMAs) of randomized controlled trials aimed to synthesize the available evidence and highlight promising avenues for intervention. Overall, the literature provides mixed and limited evidence in support of prenatal interventions. Thirty SRMAs were included. Of the 23 SRMAs that reported on prenatal depression interventions, 16 found a significant effect (average standard mean difference = -0.45, SD = 0.25). Similarly, 13 of the 20 SRMAs that reported on anxiety outcomes documented significant reductions (average standard mean difference = -0.76, SD = 0.95 or -0.53/0.53 excluding one outlier). Only 4 SRMAs reported child outcomes, and only 2 (of 10) analyses showed significant effects of prenatal interventions (massage and telephone support on neonatal resuscitation [relative risk = 0.43] and neonatal intensive care unit admissions [relative risk = 0.91]). Notably missing, perhaps due to our strict inclusion criteria (inclusion of randomized controlled trials only), were interventions focusing on key facets of prenatal health (e.g., whole diet, sleep). Structural interventions (housing, access to health care, economic security) were not included, although initial success has been documented in non-SRMAs. Most notably, none of the SRMAs focused on offspring mental health or neurodevelopmental outcomes. Given the possibility that interventions deployed in this period will positively impact the next generation, randomized trials that focus on offspring outcomes are urgently needed.

COVID-19 in the context of pregnancy, infancy and parenting (CoCoPIP) study: protocol for a longitudinal study of parental mental health, social interactions, physical growth and cognitive development of infants during the pandemic

INTRODUCTION

While the secondary impact of the COVID-19 pandemic on the psychological well-being of pregnant women and parents has become apparent over the past year, the impact of these changes on early social interactions, physical growth and cognitive development of their infants is unknown, as is the way in which a range of COVID-19-related changes have mediated this impact. This study (CoCoPIP) will investigate: (1) how parent's experiences of the social, medical and financial changes during the pandemic have impacted prenatal and postnatal parental mental health and parent-infant social interaction; and (2) the extent to which these COVID-19-related changes in parental prenatal and postnatal mental health and social interaction are associated with fetal and infant development.

METHODS AND ANALYSIS

The CoCoPIP study is a national online survey initiated in July 2020. This ongoing study (n=1700 families currently enrolled as of 6 May 2021) involves both quantitative and qualitative data being collected across pregnancy and infancy. It is designed to identify the longitudinal impact of the pandemic from pregnancy to 2 years of age as assessed using a range of parent- and self-report measures, with the aim of identifying if stress-associated moderators (ie, loss of income, COVID-19 illness, access to ante/postnatal support) appear to impact parental mental health, and in turn, infant development. In addition, we aim to document individual differences in social and cognitive development in toddlers who were born during restrictions intended to mitigate COVID-19 spread (eg, social distancing, national lockdowns).

ETHICS AND DISSEMINATION

Ethical approval was given by the University of Cambridge, Psychology Research Ethics Committee (PRE.2020.077). Findings will be made available via community engagement, public forums (eg, social media,) and to national (eg, NHS England) and local (Cambridge Universities Hospitals NHS Foundation Trust) healthcare partners. Results will be submitted for publication in peer-reviews journals.