Pandemic babies: A systematic review of the association between maternal pandemic-related stress during pregnancy and infant development

The COVID-19 pandemic, with its far-reaching influence on daily life, constituted a highly stressful experience for many people worldwide, jeopardizing individuals' mental health, particularly in vulnerable populations such as pregnant women. While a growing body of evidence links prenatal maternal stress to biological and developmental alterations in offspring, the specific impact of prenatal exposure to maternal pandemic-related stress (PRS) on infant development remains unclear. A comprehensive literature search was performed in October 2023 according to the PRISMA guidelines, which yielded a total of 28 records. The selected papers investigated a vast range of developmental and biological outcomes in the offspring with large methodological variations. The reviewed studies showed mixed results. Either direct associations between maternal PRS during pregnancy and infant temperament and socio-emotional development, or indirect links, mediated by maternal mental health, emerged in most studies. Furthermore, maternal PRS was associated with epigenetic and brain alterations in the offspring, although studies were limited in number. Collectively, the reviewed findings contribute to a deeper understanding of the role of early adverse exposures on infant development.

Exposure to family and domestic violence in the prenatal period is associated with an increased risk of hospitalization for bronchiolitis in children under 2 years

BACKGROUND

Existing research has acknowledged a correlation between stress in pregnancy and poorer respiratory health in offspring. However, research focusing on stress caused by family and domestic violence in the prenatal period is missing.

METHODS

A retrospective cohort study included children born 1987-2010 who were identified as being exposed to FDV in the prenatal period (n = 1477) from two sources: WA Police Information Management System and WA Hospital Morbidity Data Collection (HMDC) and a non-exposed comparison group (n = 41 996). Hospitalization for bronchiolitis was identified in HMDC. Cox regression was used to estimate the adjusted and unadjusted hazard ratio and 95% confidence interval for bronchiolitis hospitalizations contact.

RESULTS

Children exposed to FDV had a 70% (HR 1.70, 95% CI: 1.49-1.94) increased risk of hospitalization for bronchiolitis than non-exposed counterparts by age two. Children exposed to FDV had a longer average hospital stay for bronchiolitis than non-exposed children (4.0 days vs. 3.8 days, P < 0.001).

CONCLUSIONS

Prenatal exposure to FDV is associated with bronchiolitis hospitalization in children <2 years. Along with other risk factors, clinicians should give consideration to maternal stress factors, including experiencing FDV as a potential contributor to bronchiolitis.

Maternal social support during and after pregnancy and child cognitive ability: examining timing effects in two cohorts

BACKGROUND

Maternal anxiety, depression, and stress during and after pregnancy are negatively associated with child cognitive development. However, the contribution of positive maternal experiences, such as social support, to child cognitive development has received less attention. Furthermore, how maternal experience of social support during specific developmental periods impacts child cognitive development is largely unknown.

METHODS

Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 5784) and the Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction study (PREDO; n = 420), we investigated the associations between maternal perceived social support during and after pregnancy and child's general cognitive ability at 8 years of age, assessed with the Wechsler Intelligence Scale for Children (WISC). Bayesian relevant life course modeling was used to investigate timing effects of maternal social support on child cognitive ability.

RESULTS

In both cohorts, higher maternal perceived social support during pregnancy was associated with higher performance on the WISC, independent of sociodemographic factors and concurrent maternal symptoms of depression and anxiety. In ALSPAC, pregnancy emerged as a sensitive period for the effects of perceived social support on child cognitive ability, with a stronger effect of social support during pregnancy than after pregnancy on child cognitive ability.

CONCLUSIONS

Our findings, supported from two prospective longitudinal cohorts, suggest a distinct role of maternal perceived social support during pregnancy for cognitive development in children. Our study suggests that interventions aimed at increasing maternal social support during pregnancy may be an important strategy for promoting maternal and child well-being.

Inflammatory biomarkers and perinatal depression: A systematic review

BACKGROUND

Approximately 10 to 20% of pregnant women worldwide experience perinatal depression (PND), a depressive episode with onset during pregnancy or after childbirth. We performed a systematic review to identify, summarize and discuss studies on inflammatory biomarkers described in relation to PND.

METHOD

Inclusion criteria defined the selection of observational studies written in English, French, Spanish or Portuguese, that evaluate analytical levels of inflammatory molecules (protein levels) in biological fluids in women, with a diagnosis of depression using ICD/DSM diagnostic criteria or depressive symptoms assessed by standardized psychometric instruments, during pregnancy and/or postpartum. Case reports, experimental studies, reviews, qualitative analysis, meta-analysis, gray literature or replicated data were excluded. Three electronic databases were used for search (Pubmed, Web of Science and PsychInfo) and quality assessment of selected studies were performed using the Newcastle-Ottawa Scale. Data extraction included study design; number of subjects; obstetric information; tools and timepoints of depression and inflammatory markers assessment.

RESULTS

56 studies (sample size for cross-sectional and case-control studies ranging from 10 to 469; sample size for longitudinal studies ranging from 26 to 467), where the major aim was to analyze the association between depression and inflammatory biomarkers during pregnancy and postpartum period were included in this systematic review. Overall, the findings of our systematic review lend support to the hypothesis that several inflammatory markers may be associated with peripartum depressive symptoms. The associations were somewhat different looking at pregnancy compared to the delivery time-point and postpartum, and mainly referred to increased levels of IL-6, IL-8, CRP and TNF-α among depressed.

DISCUSSION

In summary, our systematic review findings provide evidence supporting the hypothesis that several inflammatory markers may correlate with peripartum depressive symptoms. However, our work also highlighted notable differences in the timing of biological sampling for inflammatory markers and in the methodologies used to assess depression during the perinatal period. Additionally, variations were observed in how inflammatory biomarkers and depression were approached, including their classification as exposure or outcome variables, and the timing of assessments. It is essential for future research to investigate the influence of biological fluids and the timing of assessments for both inflammatory biomarkers and depression to gain a deeper understanding of their association. This comprehensive exploration is pivotal for elucidating the intricate relationship between inflammation and perinatal depression.

Prospective associations of prenatal stress with child behavior: Moderation by the early childhood caregiving environment

Fetal exposure to prenatal stress can increase risk for psychopathology but postnatal caregiving may offset risk. This study tests whether maternal sensitivity and the home environment during early childhood modify associations of prenatal stress with offspring behavior in a sample of 127 mother-child pairs (n = 127). Mothers reported on perceived stress during pregnancy. Maternal sensitivity was rated by coders during a parent-child free play task when children were 4 years old. One year later, mothers reported on the home environment, child internalizing and externalizing behaviors, and children completed an assessment of inhibitory control. As hypothesized, the early childhood caregiving environment modified associations of prenatal stress with child behavior. Specifically, prenatal stress was associated with more internalizing behaviors at lower levels of maternal sensitivity and in home environments that were lower in emotional support and cognitive stimulation, but not at mean or higher levels. Furthermore, prenatal stress was associated with lower inhibitory control only at lower levels of maternal sensitivity, but not at higher levels. Maternal sensitivity and an emotionally supportive and cognitively stimulating home environment in early childhood may be important factors that mitigate risk for mental health problems among children exposed to prenatal stress.

Association of pica with cortisol and inflammation among Latina pregnant women

Pica, the urge to consume items generally not considered food, such as dirt, raw starch, and ice, are particularly common among pregnant women. However, the biology of pica in pregnancy is not well understood. Therefore, this study aimed to assess how pica relates to endocrine stress and immune biomarkers in a cohort of pregnant Latina women in Southern California. Thirty-four women completed a structured pica questionnaire. Maternal urinary cortisol and plasma cytokine levels were measured between 21 and 31 weeks' gestation. Associations between pica during pregnancy and biomarkers were assessed using linear regression models adjusting for gestational age. Twelve (35.3%) of the pregnant women reported pica (geophagy and amylophagy) during pregnancy. In multivariate models, those who engaged in pica had higher levels of cortisol (β: 0.37, 95% CI: 0.01, 0.073) and lower levels of IL-1β (β: -0.06, 95% CI: -0.11, -0.02), IL-8 (β: -0.30, 95% CI: -0.56, -0.05), IL-21 (β: -0.35, 95% CI: -0.63, -0.08), and type-1 inflammation composite (β: -0.29, 95% CI: -0.44, -0.14) than women who did not engage in pica. These results suggest that biological stress and immune response differ for women with pica compared to those without. This study suggests novel physiological covariates of pica during pregnancy. Further research is needed to better understand the mechanisms and temporality underlying the observed associations between pica and endocrine and immune biomarkers.

Sex-dimorphic pathways in the associations between maternal trait anxiety, infant BDNF methylation, and negative emotionality

Maternal antenatal anxiety is an emerging risk factor for child emotional development. Both sex and epigenetic mechanisms, such as DNA methylation, may contribute to the embedding of maternal distress into emotional outcomes. Here, we investigated sex-dependent patterns in the association between antenatal maternal trait anxiety, methylation of the brain-derived neurotrophic factor gene (BDNF DNAm), and infant negative emotionality (NE). Mother-infant dyads (N = 276) were recruited at delivery. Maternal trait anxiety, as a marker of antenatal chronic stress exposure, was assessed soon after delivery using the Stait-Trait Anxiety Inventory (STAI-Y). Infants' BDNF DNAm at birth was assessed in 11 CpG sites in buccal cells whereas infants' NE was assessed at 3 (N = 225) and 6 months (N = 189) using the Infant Behavior Questionnaire-Revised (IBQ-R). Hierarchical linear analyses showed that higher maternal antenatal anxiety was associated with greater 6-month-olds' NE. Furthermore, maternal antenatal anxiety predicted greater infants' BDNF DNAm in five CpG sites in males but not in females. Higher methylation at these sites was associated with greater 3-to-6-month NE increase, independently of infants' sex. Maternal antenatal anxiety emerged as a risk factor for infant's NE. BDNF DNAm might mediate this effect in males. These results may inform the development of strategies to promote mothers and infants' emotional well-being.

Placental accelerated aging in antenatal depression

BACKGROUND

Antenatal maternal depression is associated with poor pregnancy outcomes and long-term effects on the offspring. Previous studies have identified links between antenatal depression and placental DNA methylation and between placental epigenetic aging and poor pregnancy outcomes, such as preterm labor and preeclampsia. The relationship between antenatal depression and poor pregnancy outcomes may be partly mediated via placental aging.

OBJECTIVE

This study aimed to investigate whether antenatal depressive symptoms are associated with placental epigenetic age acceleration, an epigenetic aging clock measure derived from the difference between methylation age and gestational age at delivery.

STUDY DESIGN

The study included 301 women who provided placenta samples at delivery as part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies - Singletons that recruited participants from diverse race and ethnic groups at 12 US clinical sites (2009-2013). Women underwent depression screening using the Edinburgh Postnatal Depression Scale up to 6 times across the 3 trimesters of pregnancy. Depressive symptoms status was determined for each pregnancy trimester using an Edinburgh Postnatal Depression Scale score, in which a score of ≥10 was defined as having depressive symptoms and a score of <10 was defined as not having depressive symptoms. Placental DNA methylation was profiled from placenta samples. Placental epigenetic age was estimated using a methylation-based age estimator (placental "epigenetic clock") that has previously been found to have high placental gestational age prediction accuracy for uncomplicated term pregnancies. Placental age acceleration was defined to be the residual upon regressing the estimated epigenetic age on gestational age at delivery. Associations between an Edinburgh Postnatal Depression Scale score of ≥10 and an Edinburgh Postnatal Depression Scale score of <10 in the first, second, and third trimesters of pregnancy (ie, depressive symptoms vs none in each trimester) and placental age acceleration were tested using multivariable linear regression adjusting for maternal age, parity, race and ethnicity, and employment.

RESULTS

There were 31 (10.3%), 48 (16%), and 49 (16.4%) women with depressive symptoms (ie, Edinburgh Postnatal Depression Scale score of ≥10) in the first, second, and third trimesters of pregnancy, respectively. Of these women, 21 (7.2%) had sustained first- and second-trimester depressive symptoms, 19 (7%) had sustained second- and third-trimester depressive symptoms, and 12 (4.8%) had sustained depressive symptoms throughout pregnancy. Women with depressive symptoms in the second trimester of pregnancy had 0.41 weeks higher placental age acceleration than women without depressive symptoms during the second trimester of pregnancy (β=0.21 weeks [95% confidence interval, -0.17 to 0.58; P=.28] during the first trimester of pregnancy; β=0.41 weeks [95% confidence interval, 0.10-0.71; P=.009] during the second trimester of pregnancy; β=0.17 weeks [95% confidence interval, -0.14 to 0.47; P=.29] during the third trimester of pregnancy). Sustained first- and second-trimester depressive symptoms were associated with 0.72 weeks higher placental age acceleration (95% confidence interval, 0.29-1.15; P=.001) than no depressive symptom in the 2 trimesters. The association between second-trimester depressive symptoms and higher placental epigenetic age acceleration strengthened in the analysis of pregnancies with male fetuses (β=0.53 weeks; 95% confidence interval, 0.06-1.08; P=.03) but was not significant in pregnancies with female fetuses.

CONCLUSION

Antenatal depressive symptoms during the second trimester of pregnancy were associated with an average of 0.41 weeks of increased placental age acceleration. Accelerated placental aging may play an important role in the underlying mechanism linking antenatal depression to pregnancy complications related to placental dysfunction.

Obesity in pregnancy-Long-term effects on offspring hypothalamic-pituitary-adrenal axis and associations with placental cortisol metabolism: A systematic review

Obesity, affecting one in three pregnant women worldwide, is not only a major obstetric risk factor. The resulting low-grade inflammation may have a long-term impact on the offspring's HPA axis through dysregulation of maternal, placental and fetal corticosteroid metabolism, and children born of obese mothers have increased risk of diabetes and cardiovascular disease. The long-term effects of maternal obesity on offspring neurodevelopment are, however, undetermined and could depend on the specific effects on placental and fetal cortisol metabolism. This systematic review evaluates how maternal obesity affects placental cortisol metabolism and the offspring's HPA axis. Pubmed, Embase and Scopus were searched for original studies on maternal BMI, obesity, and cortisol metabolism and transfer. Fifteen studies were included after the screening of 4556 identified records. Studies were small with heterogeneous exposures and outcomes. Two studies found that maternal obesity reduced placental HSD11β2 activity. In one study, umbilical cord blood cortisol levels were affected by maternal BMI. In three studies, an altered cortisol response was consistently seen among offspring in childhood (n = 2) or adulthood (n = 1). Maternal BMI was not associated with placental HSD11β1 or HSD11β2 mRNA expression, or placental HSD11β2 methylation. In conclusion, high maternal BMI is associated with reduced placental HSD11β2 activity and a dampened cortisol level among offspring, but the data is sparse. Further investigations are needed to clarify whether the HPA axis is affected by prenatal factors including maternal obesity and investigate if adverse effects can be ameliorated by optimising the intrauterine environment.

Placental inflammatory cytokines mRNA expression and preschool children's cognitive performance: a birth cohort study in China

BACKGROUND

The immunologic milieu at the maternal-fetal interface has profound effects on propelling the development of the fetal brain. However, accessible epidemiological studies concerning the association between placental inflammatory cytokines and the intellectual development of offspring in humans are limited. Therefore, we explored the possible link between mRNA expression of inflammatory cytokines in placenta and preschoolers' cognitive performance.

METHODS

Study subjects were obtained from the Ma'anshan birth cohort (MABC). Placental samples were collected after delivery, and real-time quantitative polymerase chain reaction (RT-qPCR) was utilized to measure the mRNA expression levels of IL-8, IL-1β, IL-6, TNF-α, CRP, IFN-γ, IL-10, and IL-4. Children's intellectual development was assessed at preschool age by using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). Multiple linear regression and restricted cubic spline models were used for statistical analysis.

RESULTS

A total of 1665 pairs of mother and child were included in the analysis. After adjusting for confounders and after correction for multiple comparisons, we observed that mRNA expression of IL-8 (β =  - 0.53; 95% CI, - 0.92 to - 0.15), IL-6 (β =  - 0.58; 95% CI, - 0.97 to - 0.19), TNF-α (β =  - 0.37; 95% CI, - 0.71 to - 0.02), and IFN-γ (β =  - 0.31; 95% CI, - 0.61 to - 0.03) in the placenta was negatively associated with preschoolers' full scale intelligence quotient (FSIQ). Both higher IL-8 and IL-6 were associated with lower children's low fluid reasoning index (FRI), and higher IFN-γ was associated with lower children's working memory index (WMI). After further adjusting for confounders and children's age at cognitive testing, the integrated index of six pro-inflammatory cytokines (index 2) was found to be significantly and negatively correlated with both the FSIQ and each sub-dimension (verbal comprehension index (VCI), visual spatial index (VSI), FRI, WMI, processing speed index (PSI)). Sex-stratified analyses showed that the association of IL-8, IFN-γ, and index 2 with children's cognitive development was mainly concentrated in boys.

CONCLUSIONS

Evidence of an association between low cognitive performance and high expression of placental inflammatory cytokines (IL-8, IL-6, TNF-α, and IFN-γ) was found, highlighting the potential importance of intrauterine placental immune status in dissecting offspring cognitive development.

Associations of prenatal maternal depressive symptoms with cord blood glucocorticoids and child hair cortisol levels in the project viva and the generation R cohorts: a prospective cohort study

BACKGROUND

Prior studies have reported conflicting results regarding the association of prenatal maternal depression with offspring cortisol levels. We examined associations of high levels of prenatal depressive symptoms with child cortisol biomarkers.

METHODS

In Project Viva (n = 925, Massachusetts USA), mothers reported their depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy, cord blood glucocorticoids were measured at delivery, and child hair cortisol levels were measured in mid-childhood (mean (SD) age: 7.8 (0.8) years) and early adolescence (mean (SD) age: 13.2 (0.9) years). In the Generation R Study (n = 1644, Rotterdam, The Netherlands), mothers reported depressive symptoms using the Brief Symptom Inventory (BSI) during pregnancy, and child hair cortisol was measured at a mean (SD) age of 6.0 (0.5) years. We used cutoffs of ≥ 13 for the EPDS and > 0.75 for the BSI to indicate high levels of prenatal depressive symptoms. We used multivariable linear regression models adjusted for child sex and age (at outcome), and maternal pre-pregnancy BMI, education, social support from friends/family, pregnancy smoking status, marital status, and household income to assess associations separately in each cohort. We also meta-analyzed childhood hair cortisol results from both cohorts.

RESULTS

8.0% and 5.1% of women respectively experienced high levels of prenatal depressive symptoms in Project Viva and the Generation R Study. We found no associations between high levels of maternal depressive symptoms during pregnancy and child cortisol biomarkers in either cohort.

CONCLUSIONS

The present study does not find support for the direct link between high levels of maternal depressive symptoms and offspring cortisol levels.

Association between prenatal maternal anxiety and/or stress and offspring's cognitive functioning: A meta-analysis

This meta-analysis examined the relationship between prenatal maternal stress and/or anxiety and the outcomes of children aged 3 months to 9 years. Of the 8754 studies published before June 2021 that were synthesized, 17 conducted in Western countries were included in the meta-analysis (Ntotal  = 23,307; Mmales 54%; Methnicity White 77%, Pacific 15%, African American/Black 10%, Middle Eastern 7%, Eastern 8%). Effect sizes ranged from -0.41 to 0.15. A weak negative association was found between prenatal stress and/or anxiety exposure and children's general intellectual development. Associations varied based on the type of exposure. Findings are limited to developed counties and cannot be generalized to low- and middle-income countries. Directions for maternal prenatal intervention and future studies are discussed.

Is There an Inflammatory Profile of Perinatal Depression?

PURPOSE OF REVIEW

To synthesize and critically examine recent evidence regarding associations between immune system activity and perinatal depression.

RECENT FINDINGS

Despite a significant number of studies assessing potential immunological markers of perinatal depression, it does not appear that levels of any individual pro- or anti-inflammatory marker is a useful predictor of perinatal depression. Some recent studies have observed differences in overall immune system functioning and adaptation across this period, taking into account multiple pro- and anti- inflammatory markers. Furthermore, there is evidence for interactions between depression and maternal psychosocial factors. Immune system functioning may be a mechanism through which social determinants of health contribute to risk for perinatal depression. There is substantial evidence implicating dysregulated immune activity in perinatal depression, yet little clarity regarding a consistent immune profile, especially based on analysis of circulating peripheral cytokines.

Associations between the human immune system and gut microbiome with neurodevelopment in the first 5 years of life: A systematic scoping review

The aim of this review was to map the literature assessing associations between maternal or infant immune or gut microbiome biomarkers and child neurodevelopmental outcomes within the first 5 years of life. We conducted a PRISMA-ScR compliant review of peer-reviewed, English-language journal articles. Studies reporting gut microbiome or immune system biomarkers and child neurodevelopmental outcomes prior to 5 years were eligible. Sixty-nine of 23,495 retrieved studies were included. Of these, 18 reported on the maternal immune system, 40 on the infant immune system, and 13 on the infant gut microbiome. No studies examined the maternal microbiome, and only one study examined biomarkers from both the immune system and the gut microbiome. Additionally, only one study included both maternal and infant biomarkers. Neurodevelopmental outcomes were assessed from 6 days to 5 years. Associations between biomarkers and neurodevelopmental outcomes were largely nonsignificant and small in effect size. While the immune system and gut microbiome are thought to have interactive impacts on the developing brain, there remains a paucity of published studies that report biomarkers from both systems and associations with child development outcomes. Heterogeneity of research designs and methodologies may also contribute to inconsistent findings. Future studies should integrate data across biological systems to generate novel insights into the biological underpinnings of early development.

Maternal pandemic-related stress during pregnancy associates with infants' socio-cognitive development at 12 months: A longitudinal multi-centric study

BACKGROUND

Prenatal maternal stress is a key risk factor for infants' development. Previous research has highlighted consequences for infants' socio-emotional and cognitive outcomes, but less is known for what regards socio-cognitive development. In this study, we report on the effects of maternal prenatal stress related to the COVID-19 pandemic on 12-month-old infants' behavioral markers of socio-cognitive development.

METHODS

Ninety infants and their mothers provided complete longitudinal data from birth to 12 months. At birth, mothers reported on pandemic-related stress during pregnancy. At infants' 12-month-age, a remote mother-infant interaction was videotaped: after an initial 2-min face-to-face episode, the experimenter remotely played a series of four auditory stimuli (2 human and 2 non-human sounds). The auditory stimuli sequence was counterbalanced among participants and each sound was repeated three times every 10 seconds (Exposure, 30 seconds) while mothers were instructed not to interact with their infants and to display a neutral still-face expression. Infants' orienting, communication, and pointing toward the auditory source was coded micro-analytically and a socio-cognitive score (SCS) was obtained by means of a principal component analysis.

RESULTS

Infants equally oriented to human and non-human auditory stimuli. All infants oriented toward the sound during the Exposure episode, 80% exhibited any communication directed to the auditory source, and 48% showed at least one pointing toward the sound. Mothers who reported greater prenatal pandemic-related stress had infants with higher probability of showing no communication, t = 2.14 (p = .035), or pointing, t = 1.93 (p = .057). A significant and negative linear association was found between maternal prenatal pandemic-related stress and infants' SCS at 12 months, R2 = .07 (p = .010), while adjusting for potential confounders.

CONCLUSIONS

This study suggests that prenatal maternal stress during the COVID-19 pandemic might have increased the risk of an altered socio-cognitive development in infants as assessed through an observational paradigm at 12 months. Special preventive attention should be devoted to infants born during the pandemic.

Evaluation of maternal-infant dyad inflammatory cytokines in pregnancies affected by maternal SARS-CoV-2 infection in early and late gestation

OBJECTIVE

SARS-CoV-2 infection induces significant inflammatory cytokine production in adults, but infant cytokine signatures in pregnancies affected by maternal SARS-CoV-2 are less well characterized. We aimed to evaluate cytokine profiles of mothers and their infants following COVID-19 in pregnancy.

STUDY DESIGN

Serum samples at delivery from 31 mother-infant dyads with maternal SARS-CoV-2 infection in pregnancy (COVID) were examined in comparison to 29 control dyads (Control). Samples were evaluated using a 13-plex cytokine assay.

RESULTS

In comparison with controls, interleukin (IL)-6 and interferon gamma-induced protein 10 (IP-10) were higher in COVID maternal and infant samples (p < 0.05) and IL-8 uniquely elevated in COVID infant samples (p < 0.05). Significant elevations in IL-6, IP-10, and IL-8 were found among both early (1st/2nd Trimester) and late (3rd Trimester) maternal SARS-CoV-2 infections.

CONCLUSIONS

Maternal SARS-CoV-2 infections throughout gestation are associated with increased maternal and infant inflammatory cytokines at birth with potential to impact long-term infant health.

Maternal caregiving moderates the impact of antenatal maternal cortisol on infant stress regulation

BACKGROUND

Emerging evidence suggests that antenatal exposure to maternal stress signals affects the development of the infant stress response systems. Animal studies indicate that maternal sensitive caregiving can reverse some of these effects. However, the generalizability of these findings to humans is unknown. This study investigated the role of maternal caregiving in the association between multiple markers of maternal antenatal stress and infant stress regulation.

METHODS

The sample consisted of 94 mother-infant (N = 47 males, mean postnatal weeks = 12; SD = 1.84) dyads. Maternal levels of Interleukin-6, C-Reactive Protein (CRP), diurnal cortisol and alpha amylase, depressive and anxiety symptoms were assessed in late pregnancy (mean gestational age = 34.76; SD = 1.12), whereas postnatal symptomatology, caregiving, and infant cortisol response to the inoculation were evaluated at 3 months.

RESULTS

Hierarchical linear models (HLMs) showed a significant interaction between maternal antenatal cortisol, caregiving, and time on infant cortisol reactivity, while controlling for gender, maternal age, and postnatal depression. Specifically, higher levels of maternal antenatal cortisol were associated with greater cortisol response only among infants of less emotionally available mothers. All other markers of antenatal stress were not significantly associated with infant cortisol reactivity either independently or in interaction with maternal caregiving.

CONCLUSIONS

Albeit preliminary, results provide the first evidence in humans that maternal sensitive caregiving may eliminate the association between antenatal maternal cortisol and infant cortisol regulation.

Programming of Vascular Dysfunction by Maternal Stress: Immune System Implications

A growing body of evidence highlights that several insults during pregnancy impact the vascular function and immune response of the male and female offspring. Overactivation of the immune system negatively influences cardiovascular function and contributes to cardiovascular disease. In this review, we propose that modulation of the immune system is a potential link between prenatal stress and offspring vascular dysfunction. Glucocorticoids are key mediators of stress and modulate the inflammatory response. The potential mechanisms whereby prenatal stress negatively impacts vascular function in the offspring, including poor hypothalamic–pituitary–adrenal axis regulation of inflammatory response, activation of Th17 cells, renin–angiotensin–aldosterone system hyperactivation, reactive oxygen species imbalance, generation of neoantigens and TLR4 activation, are discussed. Alterations in the immune system by maternal stress during pregnancy have broad relevance for vascular dysfunction and immune-mediated diseases, such as cardiovascular disease.

Maternal and early life exposures and their potential to influence development of the microbiome

At the dawn of the twentieth century, the medical care of mothers and children was largely relegated to family members and informally trained birth attendants. As the industrial era progressed, early and key public health observations among women and children linked the persistence of adverse health outcomes to poverty and poor nutrition. In the time hence, numerous studies connecting genetics ("nature") to public health and epidemiologic data on the role of the environment ("nurture") have yielded insights into the importance of early life exposures in relation to the occurrence of common diseases, such as diabetes, allergic and atopic disease, cardiovascular disease, and obesity. As a result of these parallel efforts in science, medicine, and public health, the developing brain, immune system, and metabolic physiology are now recognized as being particularly vulnerable to poor nutrition and stressful environments from the start of pregnancy to 3 years of age. In particular, compelling evidence arising from a diverse array of studies across mammalian lineages suggest that modifications to our metagenome and/or microbiome occur following certain environmental exposures during pregnancy and lactation, which in turn render risk of childhood and adult diseases. In this review, we will consider the evidence suggesting that development of the offspring microbiome may be vulnerable to maternal exposures, including an analysis of the data regarding the presence or absence of a low-biomass intrauterine microbiome.

Maternal mood moderates the trajectory of emotional and behavioural problems from pre- to during the COVID-19 lockdown in preschool children

The COVID-19 outbreak and subsequent lockdown have dramatically impacted families' life, raising serious concerns about children's emotional wellbeing. However, few studies have investigated whether the impact of the COVID-19 lockdown on psychological adjustment in youngest can be moderated by maternal mood and, to our knowledge, none of them has adopted a longitudinal design. The main aim of the current study was to explore if the intensity and directionality of maternal mood symptoms moderated the trajectory of emotional and behavioural problems in Italian pre-schoolers from pre- to during the lockdown adopting a longitudinal design. To assess maternal anxiety and depression symptoms, the EPDS and the STAI-Y were filled in by 94 and 88 women before the lockdown, when their children were 1 (Wave P1) and 3 years old (Wave P2), respectively, and by 74 women during the lockdown, when their children were 4 years old (Wave L). Mothers also filled in the CBCL/1 ½-5 to assess their children's emotional and behavioural problems at each assessment wave. As a whole, children's emotional and behavioural problems significantly increased from pre- to during the lockdown. Furthermore, maternal mood moderated this trajectory. In particular, greater maternal mood symptoms were significantly associated with a greater increase in emotional reactive, anxious-depressed, withdrawn and aggressive symptoms during the lockdown. These results contribute to shed light on the role played by maternal emotional wellbeing in buffering the impact of the COVID-19 lockdown on children's behavioural development. Albeit preliminary, the current findings highlight the need to provide timely psychological interventions to distressed mothers to help their children to better cope with the effects of the pandemic.

Prenatal mother-father cortisol linkage predicts infant executive functions at 24 months

The present study investigated associations between prenatal mother-father cortisol linkage and infant executive functions. Data come from an international sample (N = 358) of predominantly white and middle- to upper-class first-time parents. During late pregnancy, parents collected diurnal salivary cortisol samples and reported on levels of psychological stress. At 24 months, children completed a battery of executive function tasks. Parent cortisol linkage was operationalized as the time-dependent, within-dyad association between maternal and paternal diurnal cortisol. Results indicated that prenatal linkage was positively related to infant executive functions, suggesting that stronger mother-father cortisol linkage was associated with higher executive function scores. Additionally, this relation was moderated by paternal average cortisol levels such that executive function scores were lower when fathers had higher average cortisol levels and linkage was weak. This association suggests that elevated paternal cortisol amplifies the negative relation between lower cortisol linkage and lower infant executive function scores. Importantly, these findings were observed while controlling for observational measures of caregiving and self-report measures of psychosocial functioning and infant social-emotional behavior. These results suggest that prenatal linkage of mother's and father's stress physiology plays a potentially important part in programming and regulating infant neurocognitive development.

Prenatal IL-6 levels and activation of the tryptophan to kynurenine pathway are associated with depressive but not anxiety symptoms across the perinatal and the post-partum period in a low-risk sample

Depression and anxiety symptoms are highly prevalent among women during pregnancy and post-partum. Previous studies suggest that one of the pathophysiological underpinnings could be an enhanced metabolism of tryptophan (Trp) into kynurenine (Kyn) due to increased inflammation. However, the longitudinal changes in the Kyn pathway and the complex interplay with inflammation and stress in women with perinatal depressive or anxiety symptoms are incompletely understood. We examined a cohort of healthy women at 34-36 gestational weeks. One hundred and ten women were assessed for salivary cortisol and 97 participants were also assessed for serum levels of Trp, Kyn and Interleukin 6 (IL-6). Women filled in two screening questionnaires for depressive (Edinburgh Postnatal Depression Scale (EPDS)) and anxiety (State Trait Anxiety Inventory subscale (STAI-S)) symptoms at 34-36 gestational weeks, delivery, 3 and 12 months postpartum. Unexpectedly, lower prenatal Kyn levels were associated with higher depressive symptoms in late pregnancy. Furthermore, prenatal Trp levels and the Kyn/Trp ratio moderate the association between IL-6 levels and depressive symptoms during the perinatal and the post-partum period. We found no interactions between Trp and Kyn biomarkers and cortisol on depressive symptoms. The observed associations were more robustly found for depressive symptoms, whereas weak and non-significant effects were found for the trajectory of anxiety symptoms. Overall, our data support the involvement of the Trp to Kyn pathway and inflammation in the course of depressive but not anxiety symptoms in women from late pregnancy until one-year post-partum, providing new evidence on the mechanisms regulating emotions during pregnancy and after delivery in a low-risk sample.

The biological underpinnings of perinatal depressive symptoms: A multi-systems approach

BACKGROUND

Well-established evidence exists of an association between depressive symptoms and alterations in the stress and inflammatory response systems; however, the picture is far less coherent during the perinatal period. This study combines the assessment of multiple stress and inflammatory biomarkers in late pregnancy and after delivery in order to investigate cross-sectional and prospective associations with perinatal depressive symptoms.

METHODS

One-hundred-ten healthy women were assessed in late pregnancy (mean gestational age=34.76; SD=1.12) and 89 were re-evaluated after delivery (mean hours after delivery=52.36; SD=19.70) for depressive and anxiety symptoms through the Edinburgh Postnatal Depression Scale and the State-Trait Anxiety Inventory. Serum Interleukin-6 (IL-6), C-Reactive Protein (CRP) and diurnal salivary cortisol levels were measured on both occasions, while diurnal salivary alpha amylase (sAA) levels were assessed in late pregnancy.

RESULTS

Using Hierarchical Linear Models, higher depressive symptoms were found to be associated with higher IL-6 levels, lower morning cortisol levels and a flatter cortisol diurnal slope during pregnancy, while adjusting for potential confounders. No significant associations were found after delivery or with change in biomarker levels from pre- to post-partum. Furthermore, preliminary evidence of a positive association between inflammation and stress markers in women with higher antenatal depressive symptoms was found.

LIMITATIONS

The sample was relatively small and highly selected, thus limiting generalizability of the findings.

CONCLUSIONS

Results emphasize the need for an integrated multi-systems approach to the understanding of the biological underpinnings of perinatal depression and suggest that the stress-immune interactions represent a promising avenue for future endeavor.