Age-related changes in the effects of stress in pregnancy on infant motor development by maternal report: The Queensland Flood Study

Threshold effects of prenatal stress on striatal microglia and relevant behaviors

Prenatal stress, a risk factor for neurodevelopmental disorders (NDDs), leads to immune alterations, including offspring neuroimmune cells. Differences in offspring outcomes may arise from whether the extent of prenatal stress crosses "thresholds" for effects on specific outcomes. Therefore, we sought to determine offspring outcomes using models with different extents of prenatal stress. We focused on striatal outcomes, because of their relevance for NDDs. Pregnant CD1 mice were assigned to four groups (each: N=6): no stress ("NoS") or one of the following stressors administered three times daily: i.p. saline injections (low prenatal stress, LoS), Interleukin-6 injections as a component of prenatal stress (immune prenatal stress; ImS), or restraint stress + saline injections (high prenatal stress, HiS), embryonic day 12-18. In adult offspring, HiS altered striatal-dependent behavior across males and females, while ImS induced fewer behavioral changes, and LoS did not affect behavior. Adult striatal microglia morphologies were mostly unchanged across groups, with only HiS leading to altered striatal density of minimally ramified cells. However, embryonic striatal microglia were affected by all models of stress, albeit in distinct ways. The HiS model, and to a lesser extent LoS, also influenced immune components of the maternal-fetal interface: placental macrophages. In conclusion, high and immune stress affected adult striatal-dependent behavior, exceeding the threshold necessary for persistent impacts, but all stress models affected embryonic microglia, suggesting that early neuroimmune outcomes had a lower threshold for impacts. Distinct severities and aspects of prenatal stress may therefore underlie different outcomes relevant to NDDs.

Flooding and health in Australia: a scoping review and coauthorship analysis of published research

BACKGROUND

Australia is frequently affected by floods, and their severity and frequency are predicted to increase due to the effects of climate change. Over the past decade, there has been an increase in the number of publications reporting on the health impacts of flooding in Australia, but no synthesis of this research evidence has previously been published. The aim of this scoping review is to identify and map publications on the health impacts of flooding in Australia and to describe the networks of researchers contributing to this research.

METHODS

In the study, we applied the scoping review methodology guided by Johanna Briggs Institute and coauthorship network analysis. Searches were conducted in MEDLINE, Embase, PsycINFO, CINHAL, Scopus and Web of Science for all publications up to 31 December 2023. Screening, full-text review and data extraction were completed by two independent reviewers. Coauthor networks were constructed using social network analysis methods.

RESULTS

69 publications were included, spanning a 70-year period from 1951 to 2023. The top three health impacts studied were post-traumatic stress disorder (PTSD), distress and child developmental outcomes, with the predominant focus in the past 10 years of recent publications on prenatal maternal stress, child outcomes and mental health impacts. There was minimal focus on socially vulnerable groups and long-term health impacts and few qualitative research studies were reported. Coauthorship analysis showed the primarily disease-specific nature of flood-related research.

CONCLUSION

Our review enhances understanding of the research on the physical and mental health impacts of flooding in Australia by identifying the areas of relatively greater research activity, existing research gaps and potential future research priorities. Given the context-dependent nature of flood and other climate-related health impacts, and of mitigation and adaptation responses, we anticipate that our review findings will enhance the understanding of this topic for Australia and other higher-income countries, identifying areas of focus and current research gaps.

Natural Disasters as a Maternal Prenatal Stressor and Children's Neurodevelopment: A Systematic Review

The intrauterine period is a time of high sensitivity in the development of the embryo and the fetus. Therefore, low levels of maternal stress are closely associated with healthy brain development in the neonatal and early childhood periods. There is increasing evidence linking natural disasters as prenatal maternal stress (PNMS) to neurodevelopmental disorders (including subclinical manifestations). Natural disasters involve many factors in addition to the trauma they cause, including loss and the physical and psychosocial difficulties that result from that trauma. This review article aims to bring together research findings on the neurodevelopmental effects of natural disasters on children as PNMS. It also looks at how factors such as gestational age and gender contribute to these effects. We conducted a systematic review on PubMed, Web of Science, and Scopus, with 30 studies meting the inclusion criteria. This systematic review was conducted in accordance with the PRISMA guidelines. A total of 1,327,886 mother-child dyads participated in the included studies. The results of the studies indicate that natural disasters have a negative impact on children's outcomes in terms of cognitive development, language development, autism/autism-like features, motor skills, performance in mathematics, mental development, sleep, attention, behavioral and emotional problems, and various psychiatric comorbidities.

IFPA Joan Hunt Senior Award in Placentology lecture: Extracellular vesicle signalling and pregnancy

The field of extracellular vesicle (EV) signalling has the potential to transform our understanding of maternal-fetal communication and affords new opportunities for non-invasive prenatal testing and therapeutic intervention. EVs have been implicated in implantation, placentation, maternal adaptation to pregnancy and complications of pregnancy, being detectable in maternal circulation as early as 6 weeks of pregnancy. EVs of differing biogenic origin, composition and bioactivity are released by cells to maintain homoeostasis. Induction of EV signalling is associated with aberrant cellular metabolism and manifests as changes in EV concentrations and/or composition. Characterizing such changes affords opportunity to develop more informative diagnostics and efficacious interventions. To develop accurate and reliable EV-based diagnostics requires: identification of disease-associated biomarkers in specific EV subpopulations; and rapid, reproducible and scalable sample processing. Conventional isolation methods face challenges due to co-isolation of particles with similar physicochemical properties. Methods targeting specific vesicle-surface epitopes and compatible with automated platforms show promise. Effective EV therapeutics require precise targeting, achieved through genetic engineering to release EVs expressing cell-targeting ligands and carrying therapeutic payloads. Unlike cell-based therapies, this approach offers advantages including: low immunogenicity; stability; and long-term storage. Although EV diagnostics and therapeutics in reproductive biology are nascent, available technologies can enhance our understanding of EV signalling between mother and fetus, its role in pregnancies and improve outcomes.

Prenatal stress impacts foetal neurodevelopment: Temporal windows of gestational vulnerability

Prenatal maternal stressors ranging in severity from everyday occurrences/hassles to the experience of traumatic events negatively impact neurodevelopment, increasing the risk for the onset of psychopathology in the offspring. Notably, the timing of prenatal stress exposure plays a critical role in determining the nature and severity of subsequent neurodevelopmental outcomes. In this review, we evaluate the empirical evidence regarding temporal windows of heightened vulnerability to prenatal stress with respect to motor, cognitive, language, and behavioural development in both human and animal studies. We also explore potential temporal windows whereby several mechanisms may mediate prenatal stress-induced neurodevelopmental effects, namely, excessive hypothalamic-pituitary-adrenal axis activity, altered serotonin signalling and sympathetic-adrenal-medullary system, changes in placental function, immune system dysregulation, and alterations of the gut microbiota. While broadly defined developmental windows are apparent for specific psychopathological outcomes, inconsistencies arise when more complex cognitive and behavioural outcomes are considered. Novel approaches to track molecular markers reflective of the underlying aetiologies throughout gestation to identify tractable biomolecular signatures corresponding to critical vulnerability periods are urgently required.

Maternal lifetime stress and psychological functioning in pregnancy is associated with preschoolers' temperament: Exploring effect modification by race and ethnicity

BACKGROUND

Psychosocial stress and psychopathology frequently co-occur, with patterns differing by race and ethnicity. We used statistical mixtures methodology to examine associations between prenatal stress and child temperament in N = 382 racially and ethnically diverse maternal-child dyads to disentangle associations among maternal stressful life events, maternal psychological functioning in pregnancy, childhood neurobehavior, and maternal race and ethnicity.

METHODS

This study utilized data from a longitudinal pregnancy cohort, PRogramming of Intergenerational Stress Mechanisms (PRISM). Mothers completed the Lifetime Stressor Checklist-Revised, Edinburgh Postnatal Depression Scale, and Spielberger State-Trait Anxiety Scale during pregnancy. When their children were 3-5 years of age, they completed the Children's Behavior Questionnaire, which yields three temperament dimensions: Negative Affectivity (NA), Effortful Control (EC), and Surgency (S). We used weighted quantile sum regression to derive a weighted maternal stress index encompassing lifetime stress and depression and anxiety symptoms and examined associations between the resulting stress index and child temperament. Differential contributions of individual stress domains by race and ethnicity also were examined.

RESULTS

Mothers self-identified as Black/Black Hispanic (46.1 %), non-Black Hispanic (31.9 %), or non-Hispanic White (22 %). A higher maternal stress index was significantly associated with increased child NA (β = 0.72 95 % CI = 0.35, 1.10). Lifetime stress was the strongest contributor among Hispanic (36.7 %) and White (17.8 %) mothers, whereas depressive symptoms in pregnancy was the strongest contributor among Black (16.7 %) mothers.

CONCLUSION

Prenatal stress was most strongly associated with negative affectivity in early childhood. Consideration of multiple stress measures as a mixture accounted for differential contributions of individual stress domains by maternal race and ethnicity. These findings may help elucidate the etiology of racial/ethnic disparities in childhood neurobehavior.

Prenatal and Postnatal Maternal Depressive Symptoms Are Associated With White Matter Integrity in 5-Year-Olds in a Sex-Specific Manner

BACKGROUND

Prenatal and postnatal maternal psychological distress predicts various detrimental consequences on social, behavioral, and cognitive development of offspring, especially in girls. Maturation of white matter (WM) continues from prenatal development into adulthood and is thus susceptible to exposures both before and after birth.

METHODS

WM microstructural features of 130 children (mean age, 5.36 years; range, 5.04-5.79 years; 63 girls) and their association with maternal prenatal and postnatal depressive and anxiety symptoms were investigated with diffusion tensor imaging, tract-based spatial statistics, and regression analyses. Maternal questionnaires were collected during first, second, and third trimesters and at 3, 6, and 12 months postpartum with the Edinburgh Postnatal Depression Scale (EPDS) for depressive symptoms and Symptom Checklist-90 for general anxiety. Covariates included child's sex; child's age; maternal prepregnancy body mass index; maternal age; socioeconomic status; and exposures to smoking, selective serotonin reuptake inhibitors, and synthetic glucocorticoids during pregnancy.

RESULTS

Prenatal second-trimester EPDS scores were positively associated with fractional anisotropy in boys (p < .05, 5000 permutations) after controlling for EPDS scores 3 months postpartum. In contrast, postpartum EPDS scores at 3 months correlated negatively with fractional anisotropy (p < .01, 5000 permutations) in widespread areas only in girls after controlling for prenatal second-trimester EPDS scores. Perinatal anxiety was not associated with WM structure.

CONCLUSIONS

These results suggest that prenatal and postnatal maternal psychological distress is associated with brain WM tract developmental alterations in a sex- and timing-dependent manner. Future studies including behavioral data are required to consolidate associative outcomes for these alterations.

Prenatal anxiety during the pandemic context is related to neurodevelopment of 6-month-old babies

Prenatal anxiety and depression in pandemic context could introduce changes in the fetal developmental trajectories that, ultimately, could alter the adaptive behaviors of the offspring, potentially affecting, for example, general neurodevelopment. The sample consisted of 105 mother-child dyads, recruited between March and May 2020. The dyads were evaluated longitudinally, prenatally and postnatally (6 months). The Pandemic Impact Questionnaire, the State-Trait Anxiety Inventory, and the Beck-II Depression Inventory were used to assess indicators of maternal anxiety and depression, respectively. Regarding the babies, their mothers responded to Age and Stages: 3, which assesses different dimensions of early neurodevelopment, in addition to a closed questionnaire to identify sociodemographic and maternal and child health variables. A series of mediation models were tested to examine the association between prenatal psychopathology/negative experiences of the pandemic and neurodevelopment. The results indicated that the negative experiences of the pandemic were indirectly associated with the socio-individual and fine motor neurodevelopment of the offspring, through maternal anxiety symptoms, during the third trimester, which functioned as a mediator.  Conclusions: This study provides evidence on the mediating effects of maternal anxiety on infant neurodevelopment in contexts of early adversity. It is important to point out the need to implement public health policies that allow a timely evaluation of neurodevelopmental variables during early childhood, which can implement early interventions to reduce the risks associated with these deficits. What is Known: • Effects of maternal mental health have been reported, effects on child neurodevelopment, in motor, cognitive, linguistic and socio-emotional dimensions. • Contexts of early adversity have been associated with maternal mental health and offspring development. What is New: • The context of pandemic adversity caused by COVID-19 is associated with motor and socio-individual neurodevelopment, mediated by maternal prenatal anxiety.

Prenatal maternal stress was not associated with birthweight or gestational age at birth during COVID-19 restrictions in Australia: The BITTOC longitudinal cohort study

BACKGROUND

Various forms of prenatal maternal stress (PNMS) have been reported to increase risk for preterm birth and low birthweight. However, the associations between specific components of stress - namely objective hardship and subjective distress - and birth outcomes are not well understood.

AIMS

Here, we aimed to determine the relationship between birthweight and gestational age at birth and specific prenatal factors (infant gender and COVID-19 pandemic-related objective hardship, subjective distress, change in diet), and to determine whether effects of hardship are moderated by maternal subjective distress, change in diet, or infant gender.

MATERIALS AND METHODS

As part of the Birth in the Time of COVID (BITTOC study), women (N = 2285) who delivered in Australia during the pandemic were recruited online between August 2020 and February 2021. We assessed objective hardship and subjective distress related to the COVID pandemic and restrictions, and birth outcomes through questionnaires that were completed at recruitment and two months post-partum. Analyses included hierarchical multiple regressions.

RESULTS

No associations between maternal objective hardship or subjective distress and gestational age at birth or birthweight were identified. Lower birthweight was significantly associated with female gender (adjusted β = 0.083, P < 0.001) and with self-reported improvement in maternal diet (adjusted β = 0.059, P = 0.015).

CONCLUSIONS

In a socioeconomically advantaged sample, neither objective hardship nor subjective distress related to COVID-19 were associated with birth outcomes. Further research is warranted to understand how other individual factors influence susceptibility to PNMS and how these findings are applicable to women with lower socioeconomic status.

Fine and gross motor skills in 7-10 years old Indian children exposed to a natural disaster during early development

Fetal life and infancy are extremely sensitive to adverse environmental conditions. This study aimed to assess the effect of exposure to a natural disaster (cyclone Aila) in utero or during infancy on fine and gross motor functions in preadolescent Indian children. The study was conducted in West Bengal, India, and included approximately 700 children (7-10 years old) who were prenatally or postnatally exposed to cyclone Aila and a nonaffected group. Anthropometric measures included height, weight, and birthweight. Socioeconomic status was based on parental education, family size, and income. Motor functions were assessed using the short form of Bruininks-Oseretsky Test of Motor Proficiency (BOT-2). Statistical analyses included, for example, generalized linear models. There were no differences in motor functions relative to the timing of the exposure (trimester) during pregnancy. Compared to the controls, prenatal Aila exposure resulted in poorer performance in all BOT-2 subtests, except for fine motor precision, strength, and balance (the last in boys), while postnatal Aila exposure, compared to the controls, resulted in poorer performance in manual dexterity, bilateral coordination, balance (girls only), and speed and agility. Early life exposure to a natural disaster has long-term adverse effect on motor proficiency in children. By inference, the welfare of pregnant women and infants should be of particular concern for emergency and health services during an environmental cataclysm.

Maternal prenatal psychological distress and motor/cognitive development in two-year-old offspring: The Japan Environment and Children's Study

Maternal prenatal psychological distress, including depression and anxiety, may affect offspring's motor/cognitive development. However, research findings have been inconsistent. We used a dataset from the Japan Environment and Children's Study to evaluate associations between maternal six-item Kessler Psychological Distress Scale (K6) scores and motor/cognitive development among offspring at two years of age. Their offspring's motor/cognitive development was assessed using the Kyoto Scale of Psychological Development 2001. Records for 1859 male and 1817 female offspring were analyzed. The maternal K6 was administered twice during pregnancy: at a median of 14.6 weeks (M-T1) and 27.3 weeks (M-T2) of gestation. Multiple regression analysis was performed with the group with K6 scores ≤4 at both M-T1 and M-T2 as a reference. In the group with K6 scores ≥5 at both M-T1 and M-T2, male offspring had significantly lower developmental quotients (DQ) in the posture-motor area (partial regression coefficient [B]: -3.68, 95% confidence interval [CI]: -5.92 to -1.44) and language-social area (B: -1.93; 95%CI: -3.73 to -0.12), while female offspring had a lower DQ for the language-social area (B: -1.95; 95%CI: -3.73 to -0.17). In those with K6 scores ≥5 only at M-T1 or M-T2, male and female offspring did not differ significantly in DQ for any area. Continuous maternal psychological distress from the first to the second half of pregnancy was associated with lower motor and verbal cognitive development in male offspring and lower verbal cognitive development in female offspring at 2 years compared with the group without persistent maternal prenatal psychological distress.

The Critical Roles of Early Development, Stress, and Environment in the Course of Psychosis

Psychotic disorders are highly debilitating with poor prognoses and courses of chronic illness. In recent decades, conceptual models have shaped understanding, informed treatment, and guided research questions. However, these models have classically focused on the adolescent and early adulthood stages immediately preceding onset while conceptualizing early infancy through all of childhood as a unitary premorbid period. In addition, models have paid limited attention to differential effects of types of stress; contextual factors such as local, regional, and country-level characteristics or sociocultural contexts; and the timing of the stressor or environmental risk. This review discusses emerging research suggesting that (a) considering effects specific to neurodevelopmental stages prior to adolescence is highly informative, (b) understanding specific stressors and levels of environmental exposures (i.e., systemic or contextual features) is necessary, and (c) exploring the dynamic interplay between development, levels and types of stressors, and environments can shed new light, informing a specified neurodevelopmental and multifaceted diathesis-stress model.

Prenatal and postpartum maternal mental health and neonatal motor outcomes during the COVID-19 pandemic

Background

Rates of prenatal and postpartum stress and depression in pregnant individuals have increased during the COVID-19 pandemic. Perinatal maternal mental health has been linked to worse motor development in offspring, with motor deficits appearing in infancy and early childhood. We aimed to evaluate the relationship between prenatal and postpartum stress and depression and motor outcome in infants born during the COVID-19 pandemic.

Methods

One hundred and seventeen participants completed an online prospective survey study at two timepoints: during pregnancy and within 2 months postpartum. Depression was self-reported using the Edinburgh Perinatal/Postpartum Depression Scale (EPDS), and stress via the Perceived Stress Scale (PSS). Mothers reported total infant motor ability (fine and gross) using the interRAI 0–3 Developmental Domains questionnaire.

Results

Prenatal (EPDS median=10.0, interquartile range[IQR]=6.0 – 14.0, B=-0.035, 95%CI=-0.062 to -0.007, p = 0.014) and postpartum maternal depression outcomes (median=7, IQR=4–12, B=-0.037, 95%CI= -0.066 to -0.008, p = 0.012) were significantlynegatively associated with total infant motor ability. Neither pregnancy nor postpartum perceived stress was associated with infant motor function. A cluster analysis revealed that preterm and low-birth weight infants whose mothers reported elevated depressive symptoms during pregnancy and in the postpartum period had the poorest motor outcomes.

Conclusions

Prenatal and postpartum depression, but not stress, was associated with early infant motor abilities. Preterm and low-birth weight infants whose mothers reported elevated depressive symptoms maybe at-risk of experiencing poor motor outcomes. These results highlight the importance of identifying pre- and postnatal maternal mental health issues, especially during the ongoing COVID-19 pandemic.

Number of erupted teeth at the age of 12 and 24 months

Aim: To verify the validity of maternal reports on the number of deciduous teeth erupted in their children. Methods: This cross-sectional study was performed with children enrolled in a Birth Cohort at the age of 12 months in the first stage and 24 months in the second stage. At both stages, children were clinically examined, and mothers reported the number of teeth of their children. Comparison between groups was performed using the Mann-Whitney non-paired Wilcoxon test. Level of agreement between two methods were estimated by the Observed Agreement, Weighted Kappa and Intraclass Correlation coefficients. Results: A total of 125 children were examined in the first stage, with mean number of reported teeth of 6.2. In the second stage, 149 children were examined, with mean number of reported teeth of 15.9. High level of agreement, kappa values and intraclass correlation coefficients were observed for both arches in both periods (p<0.001). Conclusions: Maternal report on the number of teeth erupted in children was reliable and valid. Thus, it seems to be a useful instrument for collecting data in population-based epidemiological studies targeting young children.

New Horizons in Mild Hypoxic-ischemic Encephalopathy: A Standardized Algorithm to Move past Conundrum of Care

Hypoxic-ischemic encephalopathy (HIE) presents clinically with a neonatal encephalopathy (NE) whereby the mild spectrum is difficult to classify immediately after birth. For decades trials have focused exclusively on infants with moderate-severe HIE s, as these infants were easier to identify after birth and had the highest risk of adverse outcomes. Twenty years after those trials, the PRIME study finally solved the first part of the conundrum by providing a definition of mild HIE in the first 6 hours. There is strong biological plausibility and preclinical evidence supporting the efficacy of therapeutic hypothermia (TH) but there is a lack of comparative clinical data to establish the risk-benefit in mild HIE. The fundamental question of how best to manage mild HIE remains unanswered. This review will summarize (1) the evidence that neonates with mild HIE are at significant risk for adverse outcomes, (2) the gaps/controversies in management, and (3) an algorithm of care is proposed to ensure standardized management of mild HIE and the direction of future trials.

Epidemiology of floods in sub-Saharan Africa: a systematic review of health outcomes

BACKGROUND

Floods have affected 2.3 billion people worldwide in the last 20 years, and are associated with a wide range of negative health outcomes. Climate change is projected to increase the number of people exposed to floods due to more variable precipitation and rising sea levels. Vulnerability to floods is highly dependent on economic wellbeing and other societal factors. Therefore, this systematic review synthesizes the evidence on health effects of flood exposure among the population of sub-Saharan Africa.

METHODS

We systematically searched two databases, Web of Science and PubMed, to find published articles. We included studies that (1) were published in English from 2010 onwards, (2) presented associations between flood exposure and health indicators, (3) focused on sub-Saharan Africa, and (4) relied on a controlled study design, such as cohort studies, case-control studies, cross-sectional studies, or quasi-experimental approaches with a suitable comparator, for instance individuals who were not exposed to or affected by floods or individuals prior to experiencing a flood.

RESULTS

Out of 2306 screened records, ten studies met our eligibility criteria. We included studies that reported the impact of floods on water-borne diseases (n = 1), vector-borne diseases (n = 8) and zoonotic diseases (n = 1). Five of the ten studies assessed the connection between flood exposure and malaria. One of these five evaluated the impact of flood exposure on malaria co-infections. The five non-malaria studies focused on cholera, scabies, taeniasis, Rhodesian sleeping sickness, alphaviruses and flaviviruses. Nine of the ten studies reported significant increases in disease susceptibility after flood exposure.

CONCLUSION

The majority of included studies of the aftermath of floods pointed to an increased risk of infection with cholera, scabies, taeniasis, Rhodesian sleeping sickness, malaria, alphaviruses and flaviviruses. However, long-term health effects, specifically on mental health, non-communicable diseases and pregnancy, remain understudied. Further research is urgently needed to improve our understanding of the health risks associated with floods, which will inform public policies to prevent and reduce flood-related health risks.

Effect of Natural Disaster-Related Prenatal Maternal Stress on Child Development and Health: A Meta-Analytic Review

The evidence supporting the idea that natural disaster-related prenatal maternal stress (PNMS) influences the child’s development has been accumulating for several years. We conducted a meta-analytical review to quantify this effect on different spheres of child development: birth outcomes, cognitive, motor, physical, socio-emotional, and behavioral development. We systematically searched the literature for articles on this topic (2756 articles retrieved and 37 articles included in the systematic review), extracted the relevant data to calculate the effect sizes, and then performed a meta-analysis for each category of outcomes (30 articles included across the meta-analyses) and meta-regressions to determine the effect of some factors of interest on the association between PNMS and child development: type of PNMS (objective, psychological, cognitive, diet), type of natural disaster (ice storm, flood/cyclone), type of report (maternal, third-party observer, medical), timing of exposure (preconception exposure included or not) and child age at assessment (under 10 or 10 years and older). We found that PNMS significantly influences all spheres of child development. Higher PNMS levels were associated with longer gestational age, larger newborns, and higher BMI and adiposity levels, as well as worse cognitive, motor, socio-emotional, and behavioral outcomes.

The Fort McMurray Mommy Baby Study: A Protocol to Reduce Maternal Stress Due to the 2016 Fort McMurray Wood Buffalo, Alberta, Canada Wildfire

Introduction: Data show that maternal stress triggered by exposure to a natural disaster before, during or just after pregnancy is associated with adverse pregnancy and newborn outcomes. In this paper, the first aim is to describe our efforts to test a simple, low-cost intervention to large numbers of women following a major natural disaster. The second aim is to outline the challenges faced and lessons learned during the execution of this natural disaster study. Methods: The setting was the May 2016 Fort McMurray Wood Buffalo wildfire in northern Alberta, Canada. Women who were pregnant or preconception at the time of the disaster were invited to participate via social media. This prospective cohort study included a randomized controlled trial to test the effectiveness of an expressive writing intervention on the levels of prenatal maternal stress and maternal, birth, and early childhood outcomes. At recruitment and at multiple timepoints postpartum, a battery of questionnaires was administered to evaluate objective and subjective stress exposure to the fire as well as maternal mental health, resilience and its contributing factors as well as infant developmental milestones. Qualitative content analysis of the expressive writing was conducted. Discussion: There is an increasing need to develop effective, wide-spread, rapid, and low-cost interventions to reduce prenatal maternal stress, increase resilience, and improve pregnancy outcomes following a natural disaster. Though analysis of data is ongoing, we highlight the strengths of this study which include strong community participation, rapid recruitment of eligible participants, low-cost intervention and data acquisition, and successful testing of the intervention. We acknowledge the challenges we encountered including the high rate of participant disqualifications or losses due to incomplete collection of online data; evacuation, dispersal, and inconsistent return to homes; and the high levels of stress accumulated post-disaster which led to inability to complete the study. Despite potential challenges, there remains a need for such research amid natural disasters.

Maternal exposure to a high-magnitude earthquake during pregnancy influences pre-reading skills in early childhood

Exposure to an adverse prenatal environment can influence fetal development and result in long-lasting changes in the offspring. However, the association between maternal exposure to stressful events during pregnancy and the achievement of pre-reading skills in the offspring is unknown. Here we examined the association between prenatal exposure to the Chilean high-magnitude earthquake that occurred on February 27th, 2010 and the development of early reading precursors skills (listening comprehension, print knowledge, alphabet knowledge, vocabulary, and phonological awareness) in children at kindergarten age. This multilevel retrospective cohort study including 3280 children, of whom 2415 were unexposed and 865 were prenatally exposed to the earthquake shows substantial evidence that maternal exposure to an unambiguously stressful event resulted in impaired pre-reading skills and that a higher detrimental effect was observed in those children who had been exposed to the earthquake during the first trimester of gestation. In addition, females were more significantly affected by the exposure to the earthquake than their male peers in alphabet knowledge; contrarily, males were more affected than females in print knowledge skills. These findings suggest that early intervention programs for pregnant women and/or children exposed to prenatal stress may be effective strategies to overcome impaired pre-reading skills in children.

Unexpected effects of expressive writing on post-disaster distress in the Hurricane Harvey Study: a randomized controlled trial in perinatal women

BACKGROUND

Expressive writing requires journaling stressor-related thoughts and feelings over four daily sessions of 15 min. Thirty years of research have popularized expressive writing as a brief intervention for fostering trauma-related resilience; however, its ability to surpass placebo remains unclear. This study aimed to determine the efficacy of expressive writing for improving post-traumatic stress symptoms in perinatal women who were living in the Houston area during major flooding caused by Hurricane Harvey.

METHODS

A total of 1090 women were randomly allocated (1:1:1) to expressive writing, neutral writing or no writing. Interventions were internet-based. Online questionnaires were completed before randomization and at 2 months post-intervention. The primary outcome was post-traumatic stress symptoms, measured with the Impact of Event Scale-Revised; secondary outcomes were affective symptoms, measured with the 40-item Inventory of Depression and Anxiety Scales. Feelings throughout the intervention were reported daily using tailored questionnaires.

RESULTS

In intention-to-treat analyses, no post-treatment between-group differences were found on the primary and secondary outcomes. Per-protocol analyses yielded similar results. A number of putative moderators were tested, but none interacted with expressive writing. Expressive writing produced greater feelings of anxiety and sadness during the intervention compared to neutral writing; further, overall experiences from the intervention mediated associations between expressive writing and greater post-traumatic stress at 2 months post-intervention.

CONCLUSIONS

Among disaster-stricken perinatal women, expressive writing was ineffective in reducing levels of post-traumatic stress, and may have exacerbated these symptoms in some.

Early Environmental Upheaval and the Risk for Schizophrenia

Why does prenatal exposure to wars, natural disasters, urbanicity, or winter increase the risk for schizophrenia? Research from the last two decades has provided rich insight about the underlying chains of causation at play during environmental upheaval, from conception to early infancy. In this review, we appraise the evidence linking schizophrenia spectrum disorder to prenatal maternal stress, obstetric complications, early infections, and maternal nutrition and other lifestyle factors. We discuss putative mechanisms, including the maternal stress system, perinatal hypoxia, and maternal-offspring immune activation. We propose that gene-environment interactions, timing during development, and sex differentiate the neuropsychiatric outcomes. Future research should pursue the translation of animal studies to humans and the longitudinal associations between early exposures, intermediate phenotypes, and psychiatric disorders. Finally, to paint a comprehensive model of risk and to harness targets for prevention, we argue that risk factors should be situated within the individual's personal ecosystem.

Maternal psychosocial stress during early gestation impairs fetal structural brain development in sheep

Maternal stress, especially during early pregnancy, predisposes offspring to neuropsychiatric disorders. We hypothesized that maternal psychosocial stress (MPS) during pregnancy affects fetal structural neurodevelopment depending on the gestational age of exposure. Fetal sheep brains were harvested at 130 days gestation (dG, term 150 dG) from ewes frequently isolated from flock-mates during early gestation (first and second trimester; n = 10) or late gestation (third trimester; n = 10), or from control flock-mates (n = 8). Immunohistochemistry for formation of neuronal processes, myelination, synaptic density, cell proliferation and programed cell death was performed on brain tissue sections. Sections of the cortical gray matter, the hippocampal CA3 region and the superficial, subcortical and deep white matter were examined morphometrically. Stress effects depended on the brain region and time of exposure. Stress during early gestation but not during late gestation reduced the amount of neuronal processes in the cerebral cortex and hippocampus by 36.9 ± 10.1% (p < 0.05, mean ± SEM) and 36.9 ± 15.8% (p < 0.05), respectively, accompanied by a decrease in synaptic density in the cerebral cortex and hippocampus by 39.8 ± 23.1% (p < 0.05) and 32.9 ± 13.4% (p < 0.01). Myelination was decreased in white matter layers on average by 44.8 ± 11.7% (p < 0.05) accompanied by reduced (glial) cell proliferation in the deep white matter by 83.6 ± 12.4% (p < 0.05). In contrast, stress during the third trimester had no effect in any brain region. Chronic MPS during the first and second trimester induced prolonged effects on neuronal network and myelin formation which might contribute to disturbed neurobehavioral, cognitive and motor development in offspring of stressed mothers.Lay summaryMany women are exposed to stressful events during pregnancy. Maternal stress especially during early pregnancy predisposes for offspring's neuropsychiatric disorders. In our sheep study, we show that disturbance of fetal brain development is a potential mechanism and is worst during 1st and 2nd trimester.

Perinatal compromise contributes to programming of GABAergic and glutamatergic systems leading to long-term effects on offspring behaviour

Extensive evidence now shows that adversity during the perinatal period is a significant risk factor for the development of neurodevelopmental disorders long after the causative event. Despite stemming from a variety of causes, perinatal compromise appears to have similar effects on the developing brain, thereby resulting in behavioural disorders of a similar nature. These behavioural disorders occur in a sex-dependent manner, with males affected more by externalising behaviours such as attention deficit hyperactivity disorder (ADHD) and females by internalising behaviours such as anxiety. Regardless of the causative event or the sex of the offspring, these disorders may begin in childhood or adolescence but extend into adulthood. A mechanism by which adverse events in the perinatal period impact later in life behaviour has been shown to be the changing epigenetic landscape. Methylation of the GAD1/GAD67 gene, which encodes the key glutamate-to-GABA-synthesising enzyme glutamate decarboxylase 1, resulting in increased levels of glutamate, is one epigenetic mechanism that may account for a tendency towards excitation in disorders such as ADHD. Exposure of the fetus or the neonate to high levels of cortisol may be the mediator between perinatal compromise and poor behavioural outcomes because evidence suggests that increased glucocorticoid exposure triggers widespread changes in the epigenetic landscape. This review summarises the current evidence and recent literature about the impact of various perinatal insults on the epigenome and the common mechanisms that may explain the similarity of behavioural outcomes occurring following diverse perinatal compromise.

Prenatal Maternal Stress and the Cascade of Risk to Schizophrenia Spectrum Disorders in Offspring

PURPOSE OF REVIEW

Disruptions in fetal development (via genetic and environmental pathways) have been consistently associated with risk for schizophrenia in a variety of studies. Although multiple obstetric complications (OCs) have been linked to schizophrenia, this review will discuss emerging evidence supporting the role of prenatal maternal stress (PNMS) in the etiology of schizophrenia spectrum disorders (SSD). In addition, findings linking PNMS to intermediate phenotypes of the disorder, such as OCs and premorbid cognitive, behavioral, and motor deficits, will be reviewed. Maternal immune and endocrine dysregulation will also be explored as potential mechanisms by which PNMS confers risk for SSD.

RECENT FINDINGS

PNMS has been linked to offspring SSD; however, findings are mixed due to inconsistent and retrospective assessments of PNMS and lack of specificity about SSD outcomes. PNMS is also associated with various intermediate phenotypes of SSD (e.g., prenatal infection/inflammation, decreased fetal growth, hypoxia-related OCs). Recent studies continue to elucidate the impact of PNMS while considering the moderating roles of fetal sex and stress timing, but it is still unclear which aspects of PNMS (e.g., type, timing) confer risk for SSD specifically. PNMS increases risk for SSD, but only in a small portion of fetuses exposed to PNMS. Fetal sex, genetics, and other environmental factors, as well as additional pre- and postnatal insults, likely contribute to the PNMS-SSD association. Longitudinal birth cohort studies are needed to prospectively illuminate the mechanisms that account for the variability in outcomes following PNMS.

Maternal wellbeing and pregnancy outcomes in anaesthetic trainees

The importance of supporting and maintaining doctors’ health and wellbeing cannot be overstated. Combined with the undisputed status of work in medicine as both strenuous and stressful, pregnancy is a unique time during which the mother and unborn baby may be at risk of adverse outcomes.

A narrative literature review is presented with a focus on studies of relevance to pregnancy in anaesthesia trainees, however much of the evidence is drawn from studies involving anaesthetic consultants, trainees in other specialties and pregnant workers in general. After a brief exploration into historical concepts in occupational hazards and adverse pregnancy outcomes, further discussion ensues on more recent evidence in relation to specialist training (or ‘residency’), the impact of work stressors and maternal psychological state on pregnancy outcomes and attitudes towards pregnancy during specialist training. Finally, occupational guidelines are considered along with the rationale for ‘pregnancy-friendly’ workplaces and suggestions for future research in this area for both the profession and employers.

Infant Behavior and Competence Following Prenatal Exposure to a Natural Disaster: The QF2011 Queensland Flood Study

This study utilized a natural disaster to investigate the effects of prenatal maternal stress (PNMS) arising from exposure to a severe flood on maternally reported infant social-emotional and behavioral outcomes at 16 months, along with potential moderation by infant sex and gestational timing of flood exposure. Women pregnant during the Queensland floods in January 2011 completed measures of flood-related objective hardship and posttraumatic stress (PTS). At 16 months postpartum, mothers completed measures describing depressive symptoms and infant social-emotional and behavioral problems (n = 123) and competence (n = 125). Greater maternal PTS symptoms were associated with reduced infant competence. A sex difference in infant behavioral problems emerged at higher levels of maternal objective hardship and PTS; boys had significantly more behavioral problems than girls. Additionally, greater PTS was associated with more behavioral problems in boys; however, this effect was attenuated by adjustment for maternal depressive symptoms. No main effects or interactions with gestational timing were found. Findings highlight specificity in the relationships between PNMS components and infant outcomes and demonstrate that the effects of PNMS exposure on behavior may be evident as early as infancy. Implications for the support of families exposed to a natural disaster during pregnancy are discussed.

Trajectories of maternal distress and risk of child developmental delays: Findings from the All Our Families (AOF) pregnancy cohort

BACKGROUND

Existing literature on the impact of the course of maternal distress symptoms in the perinatal period and beyond has mainly focused on one source of distress (e.g., anxiety or depression) and only selected aspects of child development. This study examined the relative impact of trajectories of maternal depression, anxiety, and stress symptoms from mid-pregnancy to early childhood on child communication, gross motor, fine motor, problem solving, and personal social development at three years of age.

METHODS

Data were analyzed from 1983 mother-child dyads who participated in the three-year follow-up of the All Our Families (AOF) study. Maternal distress and child development across five domains were measured using validated tools. Latent class analysis (LCA) was conducted to identify trajectories of maternal distress over time. Multivariable logistic regression was used to explore the relationship between the trajectories and child development while adjusting for the covariates.

RESULTS

At age three years, 5.2% of children were at risk communication delay; 12.7% for gross motor delay; 15.4% for fine motor delay; 11.2 for problem solving delay; and 5.6% for personal-social delay on ASQ-3 domains. Multivariable analysis showed children born to mothers with persistent high anxiety symptoms from pregnancy to 3-years postpartum had an increased risk of delays in communication and personal-social domains.

LIMITATIONS

The use of self-reported maternal mental health symptoms and maternal reported child development are the study limitations.

CONCLUSIONS

The impact of high levels of maternal anxiety symptoms on the increased risk of child developmental delay in communication and personal-social domains highlights the importance of early intervention and addressing maternal anxiety from pregnancy through early childhood.

Nrg1 deficiency modulates the behavioural effects of prenatal stress in mice

Little is known about the exact genes that confer vulnerability or resilience to environmental stressors during early neurodevelopment. Partial genetic deletion of neuregulin 1 (Nrg1) moderates the neurobehavioural effects of stressors applied in adolescence and adulthood, however, no study has yet examined its impact on prenatal stress. Here we examined whether Nrg1 deficiency in mice modulated the impact of prenatal stress on various behaviours in adulthood. Male heterozygous Nrg1 mice were mated with wild-type female mice who then underwent daily restraint stress from days 13 to 19 of gestation. Surprisingly, prenatal stress had overall beneficial effects by facilitating sensorimotor gating, increasing sociability, decreasing depressive-like behaviour, and improving spatial memory in adulthood. Such benefits were not due to any increase in maternal care, as prenatal stress decreased nurturing of the offspring. Nrg1 deficiency negated the beneficial behavioural effects of prenatal stress on all measures except sociability. However, Nrg1 deficiency interacted with prenatal stress to trigger locomotor hyperactivity. Nrg1 deficiency, prenatal stress or their combination failed to alter acute stress-induced plasma corticosterone concentrations. Collectively these results demonstrate that Nrg1 deficiency moderates the effects of prenatal stress on adult behaviour, but it does so in a complex, domain-specific fashion.

Recent Canadian efforts to develop population-level pregnancy intervention studies to mitigate effects of natural disasters and other tragedies

The preconception, pregnancy and immediate postpartum and newborn periods are times for mothers and their offspring when they are especially vulnerable to major stressors - those that are sudden and unexpected and those that are chronic. Their adverse effects can transcend generations. Stressors can include natural disasters or political stressors such as conflict and/or migration. Considerable evidence has accumulated demonstrating the adverse effects of natural disasters on pregnancy outcomes and developmental trajectories. However, beyond tracking outcomes, the time has arrived for gathering more information related to identifying mechanisms, predicting risk and developing stress-reducing and resilience-building interventions to improve outcomes. Further, we need to learn how to encapsulate both the quantitative and qualitative information available and share it with communities and authorities to mitigate the adverse developmental effects of future disasters, conflicts and migrations. This article briefly reviews prenatal maternal stress and identifies three contemporary situations (wildfire in Fort McMurray, Alberta, Canada; hurricane Harvey in Houston, USA and transgenerational and migrant stress in Pforzheim, Germany) where current studies are being established by Canadian investigators to test an intervention. The experiences from these efforts are related along with attempts to involve communities in the studies and share the new knowledge to plan for future disasters or tragedies.

The role of prenatal maternal stress in the development of childhood anxiety symptomatology: The QF2011 Queensland Flood Study

It is possible that findings suggesting a link between prenatal maternal stress (PNMS) and anxiety symptoms in offspring are confounded by postnatal and/or shared mother-child heritability effects. Following exposure to a natural disaster, the Queensland Flood Study investigated the unique and additive effects of various types of disaster-related PNMS (objective hardship, cognitive appraisal, and subjective distress) on childhood anxiety symptomatology (internalizing and/or anxiety symptom measures). Timing of flood exposure during pregnancy and child sex were examined as potential moderators. After controlling for maternal psychosocial factors, greater objective hardship as a result of the floods was significantly associated with greater anxiety symptoms (N = 114) and marginally associated with greater internalizing behaviors (N = 115). Earlier timing of the flood in pregnancy was associated with greater anxiety symptoms. No such associations were found between any PNMS measure and teacher-rated child internalizing behaviors (N = 90). Sex and timing did not moderate associations. Our findings suggest that, in isolation, increased maternal hardship due to exposure to an independent stressor, during pregnancy, may have a programming effect on childhood anxiety symptoms.

Sex Differences in Vulnerability to Prenatal Stress: a Review of the Recent Literature

PURPOSE OF REVIEW

To evaluate the degree to which recent studies provide evidence that the effects of prenatal maternal stress (PNMS) on child health outcomes vary depending on the child's biological sex. In this review, we used a broad definition of stress, including negative life events, psychological stress, and established stress biomarkers. We identified 50 peer-reviewed articles (published January 2015-December 2017) meeting the inclusion criteria.

RECENT FINDINGS

Most articles (k = 35) found evidence of either sex-specific associations (significant in one sex but not the other) or significant PNMSxstress interactions for at least one child health outcome. Evidence for sex-dependent effects was strongest in the group of studies evaluating child neural/nervous system development and temperament as outcomes. There is sufficient evidence of sex-dependent associations to recommend that researchers always consider the potential role of child sex in PNMS programming studies and report descriptive statistics for study outcomes stratified by child biological sex.

A trajectory analysis of childhood motor development following stress in pregnancy: The QF2011 flood study

This prospective, longitudinal cohort study examined the effects of flood-related stress in pregnancy on the trajectory of children's motor development; and the moderating effects of gestational timing of the flood or sex of the child. Women who were pregnant during a severe flood reported on their objective flood-related experiences, emotional reactions, and cognitive appraisal of the disaster. At 2-, 6-, 16-months, 2½- and 4-years postpartum, mothers' assessed their children's fine and gross motor development using the Ages and Stages-3 Questionnaire. High objective flood-exposure, or a negative appraisal, especially in later pregnancy, predicted poorer gross motor skills which rapidly improved across early childhood. Children's fine motor skill was influenced by the sex of the child with improvements in girls' fine motor skills over time, but not boys'. This demonstrates that stress in pregnancy has enduring influences on gross, but not fine, motor skills. Results are discussed in relation to fetal programming and stress appraisal theory.

Natural disaster-related prenatal maternal stress is associated with alterations in placental glucocorticoid system: The QF2011 Queensland Flood Study

We investigated the effects of a natural disaster (a sudden flood) as a source of prenatal maternal stress (PNMS) on the placental glucocorticoid system and glucose transporters. Whether the gestational age at the time of the flood moderated these effects was also evaluated. Placental samples were collected from participants in the 2011 Queensland Flood Study (QF2011) who were pregnant in the first or second trimester at the onset of the flood. Detailed questionnaire results for objective hardship and composite subjective distress were obtained to assess stress levels. Subjective distress was significantly associated with a reduction in placental NR3C1-β mRNA levels for males only (β = -0.491, p = 0.005). In female placentas, objective hardship was marginally linked with lower SLC2A1 mRNA levels while subjective distress was a marginally significant predictor of higher placental SLC2A4 mRNA levels. Gestational age at the time of the flood was a significant moderator of the effect of subjective distress on placental mRNA levels for NR3C1-α (p = 0.046) and HSD11B1 (p = 0.049) in male placentas: if the flood occurred in mid-pregnancy, lower subjective distress predicted higher HSD11B1 while higher subjective distress predicted lower NR3C1-α placental mRNA level. While results did not show any PNMS effects on placental HSD11B2 mRNA and protein levels, and activity, we showed a reduction in placental NR3C1-β mRNA level in male placentas. Our results show evidence of distinct placental glucocorticoid and glucose systems adaptations to PNMS as a function of fetal sex and gestational timing of exposure, with high subjective PNMS in mid-pregnancy associated with lower levels of expression of glucocorticoid-promoting gene in males, leaving the fetus less protected against maternal stress. The exact mechanism by which natural disaster-related PNMS acts on the placenta and the impact on fetal programming requires further investigation.

Disaster in pregnancy: midwifery continuity positively impacts infant neurodevelopment, QF2011 study

BACKGROUND

Research shows that continuity of midwifery carer in pregnancy improves maternal and neonatal outcomes. This study examines whether midwifery group practice (MGP) care during pregnancy affects infant neurodevelopment at 6-months of age compared to women receiving standard hospital maternity care (SC) in the context of a natural disaster.

METHODS

This prospective cohort study included 115 women who were affected by a sudden-onset flood during pregnancy. They received one of two models of maternity care: MGP or SC. The women's flood-related objective stress, subjective reactions, and cognitive appraisal of the disaster were assessed at recruitment into the study. At 6-months postpartum they completed the Ages and Stages Questionnaire (ASQ-3) on their infants' communication, fine and gross motor, problem solving, and personal-social skills.

RESULTS

Greater maternal objective and subjective stress predicted worse infant outcomes. Even when controlling for maternal stress from the flood, infants of mothers who were in the MGP model of maternity care performed better than infants of mothers in SC on two of the five ASQ-3 domains (fine motor and problem solving) at 6-months of age. Furthermore, infants in the SC model were more likely to be identified as at risk for delayed development on these domains than infants in the MGP model of care.

CONCLUSIONS

Continuity of midwifery care has positive effects on infant neurodevelopment when mothers experience disaster-related stress in pregnancy, with significantly better outcomes on two developmental domains at 6 months compared to infants whose mothers received standard hospital care.

The long-term physical and psychological health impacts of flooding: A systematic mapping

BACKGROUND

Flooding has caused significant and wide ranging long-term health impacts for affected populations. However, until now, the long-term health outcomes, epidemiological trends and specific impact factors of flooding had not been identified. In this study, the relevant literature was systematically mapped to create the first synthesis of the evidence of the long-term health impacts of flooding.

METHODS

The systematic mapping method was used to collect and categorize all the relevant literature. A study was included if it had a description or measurement of health impacts over six months after flooding. The search was limited to peer reviewed articles and grey literature written in English, published from 1996 to 2016.

RESULTS

A total of 56 critical articles were extracted for the final map, including 5 qualitative and 51 quantitative studies. Most long-term studies investigated the psychological impacts of flooding, including PTSD, depression, anxiety, psychiatric disorders, sleep disorder and suicide. Others investigated the physiological impacts, including health-related quality of life, acute myocardial infarction, chronic diseases, and malnutrition. Social support was proved to be protective factors that can improve health outcomes in the long-term after flooding. To date, there have been relatively few reviews had focused on the long-term health impacts of flooding. This study coded and catalogued the existing evidence across a wide range of variables and described the long-term health consequences within a conceptual map.

DISCUSSION AND CONCLUSIONS

Although there was no boundary between the short-term and the long-term impacts of flooding, the identified health outcomes in this systematic mapping could be used to define long-term health impacts. The studies showed that the prevalence of psychological diseases had a reversed increasing trend occurred even in the long-term in relatively poor post-flooding environments. Further cohort or longitudinal research focused on disability, chronic diseases, relocation population, and social interventions after flooding, are urgently required.

The Effects of Prenatal Maternal Stress on Early Temperament: The 2011 Queensland Flood Study

OBJECTIVE

This study examined the effects of disaster-related prenatal maternal stress on infant temperament and whether the sex of the infant or the timing of the stressor in pregnancy would moderate the effects.

METHODS

Mothers' objective experiences of a sudden-onset flood in Queensland, Australia, their subjective emotional reactions, and cognitive appraisal of the event were assessed. At 6 months postpartum, 121 mothers reported their infant's temperament on the 5 dimensions of the Short Temperament Scale for Infants.

RESULTS

When controlling for postnatal maternal factors, subjective prenatal maternal stress and cognitive appraisal of the disaster were associated with easier aspects of infant temperament. However, several interesting interactions emerged showing negative effects of the flood. With higher levels of objective hardship in pregnancy, boys (but not girls) received more irritable temperament ratings. When the flood occurred early in pregnancy, higher levels of objective hardship predicted more arrhythmic infant temperament. Finally, mothers whose emotional response to the flood exceeded the hardship they endured reported significantly more active-reactive infants.

CONCLUSION

Prenatal maternal stress from a natural disaster predicted more difficult temperament ratings that were moderated by infant sex, timing of the flood in gestation, and mother's emotional response to the disaster.

Prenatal maternal stress shapes children's theory of mind: the QF2011 Queensland Flood Study

Research shows that stress in pregnancy has powerful and enduring effects on many facets of child development, including increases in behavior problems and neurodevelopmental disorders. Theory of mind is an important aspect of child development that is predictive of successful social functioning and is impaired in children with autism. A number of factors related to individual differences in theory of mind have been identified, but whether theory of mind development is shaped by prenatal events has not yet been examined. In this study we utilized a sudden onset flood that occurred in Queensland, Australia in 2011 to examine whether disaster-related prenatal maternal stress predicts child theory of mind and whether sex of the child or timing of the stressor in pregnancy moderates these effects. Higher levels of flood-related maternal subjective stress, but not objective hardship, predicted worse theory of mind at 30 months (n=130). Further, maternal cognitive appraisal of the flood moderated the effects of stress in pregnancy on girls' theory of mind performance but not boys'. These results illuminate how stress in pregnancy can shape child development and the findings are discussed in relation to biological mechanisms in pregnancy and stress theory.