Intergenerational Transmission of Maternal Childhood Maltreatment Prior to Birth: Effects on Human Fetal Amygdala Functional Connectivity

Prenatal Social Determinants of Health: Narrative review of maternal environments and neonatal brain development

The Social Determinants of Health, a set of social factors including socioeconomic status, community context, and neighborhood safety among others, are well-known predictors of mental and physical health across the lifespan. Recent research has begun to establish the importance of these social factors at the earliest points of brain development, including during the prenatal period. Prenatal socioeconomic status, perceived stress, and neighborhood safety have all been reported to impact neonatal brain structure and function, with exploratory work suggesting subsequent effects on infant and child behavior. Secondary effects of the Social Determinants of Health, such as maternal sleep and psychopathology during pregnancy, have also been established as important predictors of infant brain development. This research not only establishes prenatal Social Determinants of Health as important predictors of future outcomes but may be effectively applied even before birth. Future research replicating and extending the effects in this nascent literature has great potential to produce more specific and mechanistic understanding of the social factors that shape early neurobehavioral development. IMPACT: This review synthesizes the research to date examining the effects of the Social Determinants of Health during the prenatal period and neonatal brain outcomes. Structural, functional, and diffusion-based imaging methodologies are included along with the limited literature assessing subsequent infant behavior. The degree to which results converge between studies is discussed, in combination with the methodological and sampling considerations that may contribute to divergence in study results. Several future directions are identified, including new theoretical approaches to assessing the impact of the Social Determinants of Health during the perinatal period.

Advances in fetal and neonatal neuroimaging and everyday exposures

The complex, tightly regulated process of prenatal brain development may be adversely affected by "everyday exposures" such as stress and environmental pollutants. Researchers are only just beginning to understand the neural sequelae of such exposures, with advances in fetal and neonatal neuroimaging elucidating structural, microstructural, and functional correlates in the developing brain. This narrative review discusses the wide-ranging literature investigating the influence of parental stress on fetal and neonatal brain development as well as emerging literature assessing the impact of exposure to environmental toxicants such as lead and air pollution. These 'everyday exposures' can co-occur with other stressors such as social and financial deprivation, and therefore we include a brief discussion of neuroimaging studies assessing the effect of social disadvantage. Increased exposure to prenatal stressors is associated with alterations in the brain structure, microstructure and function, with some evidence these associations are moderated by factors such as infant sex. However, most studies examine only single exposures and the literature on the relationship between in utero exposure to pollutants and fetal or neonatal brain development is sparse. Large cohort studies are required that include evaluation of multiple co-occurring exposures in order to fully characterize their impact on early brain development. IMPACT: Increased prenatal exposure to parental stress and is associated with altered functional, macro and microstructural fetal and neonatal brain development. Exposure to air pollution and lead may also alter brain development in the fetal and neonatal period. Further research is needed to investigate the effect of multiple co-occurring exposures, including stress, environmental toxicants, and socioeconomic deprivation on early brain development.

Trajectories of brain and behaviour development in the womb, at birth and through infancy

Birth is often seen as the starting point for studying effects of the environment on human development, with much research focused on the capacities of young infants. However, recent imaging advances have revealed that the complex behaviours of the fetus and the uterine environment exert influence. Birth is now viewed as a punctuate event along a developmental pathway of increasing autonomy of the child from their mother. Here we highlight (1) increasing physiological autonomy and perceptual sensitivity in the fetus, (2) physiological and neurochemical processes associated with birth that influence future behaviour, (3) the recalibration of motor and sensory systems in the newborn to adapt to the world outside the womb and (4) the effect of the prenatal environment on later infant behaviours and brain function. Taken together, these lines of evidence move us beyond nature-nurture issues to a developmental human lifespan view beginning within the womb.

Prioritizing Maternal Mental Health in Addressing Morbidity and Mortality

Importance

The rate of maternal mortality in the United States is 2-fold to 3-fold greater than that in other high-income countries. While many national initiatives have been developed to combat maternal mortality, these efforts often fail to include mental illness.

Objective

To highlight the underrecognized contribution of mental illness to maternal mortality, which is nearly double that of postpartum hemorrhage.

Evidence Review

A topic outline was developed to include challenges in measuring perinatal mental conditions and mortality rates; contributions of social determinants of health to mental conditions and mortality; perinatal psychiatric disorder characterization; mechanisms by which maternal mental illness increases mortality, specifically, suicide and addictive disorders; access limitations and care "deserts"; prenatal stress and its impact on reproductive outcomes; increasing clinician expertise through cross-disciplinary education; intervention sites and models; and asserting that mental health is fundamental to maternal health. Publications in the last 3 years were prioritized, particularly those relating to policy. References were selected through consensus. Sources were PubMed, Ovid, direct data published on government websites, and health policy sources such as the Policy Center for Maternal Mental Health.

Findings

Priority was given to recent sources. Citations from 2022-2023 numbered 26; within the last 5 years, 14; and historical references, 15. Recommendations to address each topic area serve as concluding statements for each section. To mitigate the contributions of mental illness to the maternal mortality risk, a coordinated effort is required across professional and governmental organizations.

Conclusions and Relevance

Concrete programmatic and policy changes are needed to reduce perinatal stress and address trauma, standardize the collection of social determinant of health data among perinatal patients, increase access to reproductive psychiatry curricula among prescribers, reduce perinatal mental health and obstetrical deserts, institute paid parental leave, and support seamless integration of perinatal and behavioral health care. Moreover, instead of focusing on a relatively minor portion of the contributors to health that current medical practice targets, fortifying the social foundation strengthens the prospects for the health of families for our current and future generations.

Toward a multi-level approach to the study of the intergenerational transmission of trauma: Current findings and future directions

A central goal in the field of developmental psychopathology is to evaluate the complex, dynamic transactions occurring among biological, psychological, and broader social-cultural contexts that predict adaptive and maladaptive outcomes across ontogeny. Here, I briefly review research on the effects of a history of childhood maltreatment on parental, child, and dyadic functioning, along with more recent studies on the intergenerational transmission of trauma. Because the experience and sequelae of child maltreatment and the intergenerational transmission of trauma are embedded in complex biopsychosocial contexts, this research is best conceptualized in a developmental psychopathology framework. Moreover, there is a pressing need for investigators in this area of study to adopt dynamic, multi-level perspectives as well as using developmentally guided, sophisticated research methods. Other directions for research in this field are suggested, including the implementation of collaborative interdisciplinary team science approaches, as well as community-based participatory research, to increase representation, inclusion, and equity of community stakeholders. A greater focus on cultural and global perspectives is also recommended.

[Research progress on the mechanism of the impact of maternal childhood trauma on intergenerational transmission]

Childhood trauma refers to trauma experiences encountered during childhood and adolescence. Maternal childhood trauma experiences have a lasting impact on the next generation, affecting their physical and mental well-being. The mechanisms involved include the hypothalamic-pituitary-adrenal axis, inflammatory factors, brain structure and function, gene interactions, and parenting styles. This paper systematically reviews the mechanisms of the impact of maternal childhood trauma on intergenerational transmission, providing insights for the prevention of intergenerational transmission of childhood trauma.