Prenatal and postnatal stress and asthma in children: Temporal- and sex-specific associations

Influence of Biological Sex and Congenital Iron Deficiency on Neonatal Cytokine Responses

BACKGROUND/OBJECTIVES

Stimulated cord blood mononuclear cell (CBMC) cytokine responses were previously shown to predict the risk of childhood atopic disease. Iron deficiency (ID) at birth may also program atopic disease. Males are at a higher risk of pediatric atopic disease, but it is not known whether congenital ID impacts CBMC immune responses differentially by sex.

METHODS

Cord blood (CB) samples were collected from healthy term or near-term neonates after elective cesarean deliveries. A transferrin saturation ≤ 25% defined congenital ID. CBMCs were stimulated with either phytohemagglutinin (PHA) or PHA plus an iron chelator.

RESULTS

Of the 85 neonates, the 26 neonates with congenital ID exhibited lower plasma tumor necrosis factor-α (TNF-α), as well as higher CBMC TNF-α and IL-8 responses than iron-sufficient neonates (p = 0.017, p = 0.013, and p = 0.007, respectively). Higher CBMC TNF-α responses were seen in both males and females with congenital ID. However, females with congenital ID also had lower plasma IL-6, lower plasma TNF-α, and higher CBMC interleukin (IL)-8 responses. Additionally, iron chelation during culture influenced stimulated CBMC IFN-γ and CBMC TNF-α responses.

DISCUSSION

Congenital ID may influence stimulated CBMC cytokine responses, but results point to a sex-specific regulation of immune balance at birth. Because males are more prone to infantile ID and more likely to develop early childhood asthma, future studies should further investigate how fetal sex and congenital iron status impacts childhood immune responsiveness to infections and antigenic stimulation from the rearing environment.

The effects of violence and related stress on asthma

In the United States, people living in deprived urban areas and persons in certain minoritized groups are often exposed to violence and affected with asthma, and epidemiologic studies have shown a link between exposure to violence (ETV) and asthma throughout the lifespan. Indeed, ETV at the individual, intrafamilial and community levels has been linked to asthma in children and adults. In this review, we discuss the evidence for a causal relation between ETV and asthma, emphasizing findings published in the last five years. Interpretation of the available evidence is limited by variable quality of the assessment of ETV or asthma, potential recall and selection bias, inability to estimate the relative contribution of various types of violence to the observed associations, lack of objective biomarkers of asthma or asthma endotypes, and inconsistent consideration of potential confounders or modifiers of the ETV-asthma link. Despite such limitations, the aggregate evidence from studies conducted in different locations and populations suggests that ETV affects asthma and asthma outcomes, and that this is explained by direct physiologic effects of violence-related distress and indirect effects (e.g., through risky health behaviors or co-morbidities). Thus, large prospective studies with careful assessment of specific types of ETV, key covariates and comorbidities (including mental illness), and asthma are needed to advance this field. Such research efforts should not preclude screening for maltreatment in children with asthma and ETV-related depression and anxiety in adolescents and adults with asthma. Further, vigorous policies are needed to curtail violence, as such policies could benefit patients with asthma while saving lives.

Prenatal Stress and Maternal Role in Neurodevelopment

This review summarizes recent findings on stress-related programming of brain development in utero, with an emphasis on situating findings within the mothers' broader psychosocial experiences. Meta-analyses of observational studies on prenatal stress exposure indicate the direction and size of effects on child neurodevelopment are heterogeneous across studies. Inspired by lifespan and topological frameworks of adversity, we conceptualize individual variation in mothers' lived experience during and prior to pregnancy as a key determinant of these heterogeneous effects across populations. We structure our review to discuss experiential categories that may uniquely shape the psychological and biological influence of stress on pregnant mothers and their developing children, including current socioeconomic resources, exposure to chronic and traumatic stressors, culture and historical trauma, and the contours of prenatal stress itself. We conclude by identifying next steps that hold potential to meaningfully advance the field of fetal programming.

Associations between psychosocial stress, child's anxiety, and lung function in mid-childhood

BACKGROUND

Reducing the risk of respiratory disease during the plastic stages of lung development could have long-term health impacts. Psychosocial stress has been previously linked to adverse childhood respiratory outcomes, but the influence of child's anxiety and sex differences has not been completely elucidated.

OBJECTIVE

To evaluate the association among maternal stress, child anxiety, and lung function in children and to explore differences by sex.

METHODS

Cross-sectional analyses included 294 mother-child pairs from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) birth cohort in Mexico City. Children's lung function was tested once at ages 8 to 13 years of age, and height- and sex-adjusted z-scores were estimated for forced vital capacity, forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity and forced expiratory flow between 25% and 75%. Maternal stress was assessed through the Crisis in Family Systems-Revised (CRISYS-R) survey, used to report negative life events experienced in the past 6 months and dichotomized at the median (<3 and ≥3). Child's self-reported anxiety was assessed using the Revised Children's Manifest Anxiety Scale short form and dichotomized at the clinically relevant cutoff (T-score ≥ 60). The association among maternal stress, child anxiety, and lung function outcomes was evaluated using linear models. Effect modification by sex was evaluated with interaction terms and in stratified analyses.

RESULTS

We did not find any association between maternal stress and any lung function outcome. Clinically elevated child anxiety symptoms were associated with lower forced expiratory volume in 1 second (β = -0.36, 95% CI -0.69 to -0.02). We found no evidence of effect modification by sex.

CONCLUSION

Results highlight the importance of considering childhood mental health in relation to lung function outcomes.

Maternal stressful life events during pregnancy and childhood asthma and wheeze

BACKGROUND

Studies have linked prenatal maternal psychosocial stress to childhood wheeze/asthma but have rarely investigated factors that may mitigate risks.

OBJECTIVE

To investigate associations between prenatal stress and childhood wheeze/asthma, evaluating factors that may modify stress effects.

METHODS

Participants included 2056 mother-child dyads from Environmental influences on Child Health Outcomes (ECHO)-PATHWAYS, a consortium of 3 prospective pregnancy cohorts (the Conditions Affecting Neurocognitive Development and Learning in Early Childhood study, The Infant Development and Environment Study, and a subset of the Global Alliance to Prevent Prematurity and Stillbirth study) from 6 cities. Maternal stressful life events experienced during pregnancy (PSLEs) were reported using the Pregnancy Risk Assessment Monitoring System Stressful Life Events questionnaire. Parents reported child wheeze/asthma outcomes at age 4 to 6 years using standardized questionnaires. We defined outcomes as ever asthma, current wheeze, current asthma, and strict asthma. We used modified Poisson regression with robust standard errors (SEs) to estimate risk ratios (RRs) and 95% CI per 1-unit increase in PSLE, adjusting for confounders. We evaluated effect modification by child sex, maternal history of asthma, maternal childhood traumatic life events, neighborhood-level resources, and breastfeeding.

RESULTS

Overall, we observed significantly elevated risk for current wheeze with increasing PSLE (RR, 1.09 [95% CI, 1.03-1.14]), but not for other outcomes. We observed significant effect modification by child sex for strict asthma (P interaction = .03), in which risks were elevated in boys (RR, 1.10 [95% CI, 1.02-1.19]) but not in girls. For all other outcomes, risks were significantly elevated in boys and not in girls, although there was no statistically significant evidence of effect modification. We observed no evidence of effect modification by other factors (P interactions > .05).

CONCLUSION

Risk of adverse childhood respiratory outcomes is higher with increasing maternal PSLEs, particularly in boys.

Impact of Climate Change on Dietary Nutritional Quality and Implications for Asthma and Allergy

Asthma and allergic disorders are common in childhood with genetic and environmental determinants of disease that include prenatal nutritional exposures such as long-chain polyunsaturated fatty acids and antioxidants. Global climate change is implicated in asthma and allergic disorder morbidity with potential mechanisms including perturbations of ecosystems. There is support that environmental and climatic changes such as increasing global temperate and carbon dioxide levels affect aquatic and agricultural ecosystems with subsequent alterations in long-chain polyunsaturated fatty acid availability and nutrient quality and antioxidant capacity of certain crops, respectively. This article discusses asthma epidemiology and the influence of global climate change.

Maternal steroids during pregnancy and their associations with exposure to lifetime stressful life events, prenatal stress appraisal and psychological functioning

BACKGROUND

During pregnancy, steroids enable physiological adaptations in response to many factors, including maternal stress or psychological functioning. While stress and psychological dysfunction can have endocrine-disrupting effects beyond cortisol disruption, associations between prenatal maternal stress or related psychological dysfunction and the broader steroid milieu remain understudied.

AIM

To assess associations between independent and joint maternal stress and psychological functioning measures and steroid profiles in pregnancy (22-40 gestational weeks) in the Programming of Intergenerational Stress Mechanisms (PRISM) birth cohort (n = 334).

METHODS

Serum metabolomics detected 42 steroids and their metabolites, which were grouped into five classes (pregnenolone, androgens, estrogens, progestin, and corticosteroids). The Perceived Stress Scale, Life Stressor Checklist-Revised, and Edinburgh Postnatal Depression Scale indexed lifetime traumatic/non-traumatic stressors, global prenatal stress appraisal, and depressive symptoms during pregnancy, respectively. Exposures were categorized as high-low using the corresponding 3rd quartiles. We assessed associations between both individual and joint stress exposures with steroid classes using linear mixed effect models and with individual steroids using linear regressions. We also examined fetal sex-specific effects.

RESULTS

High prenatal perceived stress was independently associated with lower levels of androgens and estrogens in the overall sample [β (95%CI): androgens: -0.13 (-0.25;-0.01); estrogens: -0.16 (-0.31;-0.01)], particularly among women carrying males [androgens: -0.22 (-0.39;-0.05); estrogens: -0.28 (-0.50;-0.07)]. Results on estrogens were consistent when considering joint exposure to both greater lifetime stressors and higher prenatal perceived stress. We also found a single testosterone metabolite-5alpha-androstan-3alpha,17alpha-diol disulfate-negatively associated with both individual high perceived stress and joint exposure to high lifetime stressors and high perceived stress among women carrying males.

CONCLUSIONS

Increased maternal perceived stress experienced in pregnancy was independently associated with lower maternal androgen and estrogen levels during pregnancy in the overall sample, particularly among women carrying males. Results on estrogens were consistent when we considered the joint exposure of increased lifetime stressors and higher prenatal perceived stress.

Epigenome-wide meta-analysis of prenatal maternal stressful life events and newborn DNA methylation

Prenatal maternal stressful life events are associated with adverse neurodevelopmental outcomes in offspring. Biological mechanisms underlying these associations are largely unknown, but DNA methylation likely plays a role. This meta-analysis included twelve non-overlapping cohorts from ten independent longitudinal studies (N = 5,496) within the international Pregnancy and Childhood Epigenetics consortium to examine maternal stressful life events during pregnancy and DNA methylation in cord blood. Children whose mothers reported higher levels of cumulative maternal stressful life events during pregnancy exhibited differential methylation of cg26579032 in ALKBH3. Stressor-specific domains of conflict with family/friends, abuse (physical, sexual, and emotional), and death of a close friend/relative were also associated with differential methylation of CpGs in APTX, MyD88, and both UHRF1 and SDCCAG8, respectively; these genes are implicated in neurodegeneration, immune and cellular functions, regulation of global methylation levels, metabolism, and schizophrenia risk. Thus, differences in DNA methylation at these loci may provide novel insights into potential mechanisms of neurodevelopment in offspring.

Prenatal Maternal Stress and Pediatric Asthma Across Development: Adolescent Female-Specific Vulnerability

Prenatal maternal stress (PNMS) is linked to physical sequelae in offspring, including childhood asthma. This study sought to examine the roles of objective and subjective PNMS in the development of asthma at offspring ages 5 and 15. The sample included 815 mother-child dyads from the Mater Misericordiae Mothers' Hospital-University of Queensland Study of Pregnancy. PNMS was measured via retrospective self-report during pregnancy and 3-5 days after birth. Postnatal maternal stress was measured at offspring age 5. Objective PNMS was associated with elevated asthma risk at age 5 (OR 1.21, 95% CI 1.00, 1.45, p = 0.05), albeit not above concurrent postnatal stress. Sex moderated the association between PNMS and asthma at age 15, controlling for postnatal stress. Sex stratified analyses revealed a positive association between objective PNMS and age 15 asthma in females, but not males. Results provide evidence that PNMS may impact asthma outcomes in adolescence.

Perinatal Characteristics and the Sensitization to Cow Milk, Egg Whites and Wheat in Children up to 3 Years of Age

Food sensitization in early life identifies children at risk of developing allergic diseases. We investigated the sensitization to cow milk (CM), egg whites, and wheat. Newborns and infants under 3 years of age with available specific immunoglobulin E (sIgE) data were identified. A retrospective survey was conducted using data from the Chang Gung Research Database. Perinatal characteristics, such as singleton or multiples in a single pregnancy, parity, meconium staining, maternal age, spontaneous delivery or cesarean section, meconium passage, weeks of gestation, birth length, body weight, head and chest circumferences, and season, were obtained. The data on sIgE were collected, and a logistic regression model was used to determine the odds of sensitization. Positive sIgE for CM and egg whites was more likely to occur in boys than in girls. Early-life egg white and wheat sensitization was associated with increased birth body length and weight. A multivariate analysis indicated an association between egg white sIgE positivity and logarithmic total IgE. Higher total IgE levels and younger age were associated with egg white sensitization, and elevated weight and length at birth were linked to food sensitization, particularly to egg whites and wheat.

Air Pollutant impacts on the brain and neuroendocrine system with implications for peripheral organs: a perspective

Air pollutants are being increasingly linked to extrapulmonary multi-organ effects. Specifically, recent studies associate air pollutants with brain disorders including psychiatric conditions, neuroinflammation and chronic diseases. Current evidence of the linkages between neuropsychiatric conditions and chronic peripheral immune and metabolic diseases provides insights on the potential role of the neuroendocrine system in mediating neural and systemic effects of inhaled pollutants (reactive particulates and gases). Autonomically-driven stress responses, involving sympathetic-adrenal-medullary and hypothalamus-pituitary-adrenal axes regulate cellular physiological processes through adrenal-derived hormones and diverse receptor systems. Recent experimental evidence demonstrates the contribution of the very stress system responding to non-chemical stressors, in mediating systemic and neural effects of reactive air pollutants. The assessment of how respiratory encounter of air pollutants induce lung and peripheral responses through brain and neuroendocrine system, and how the impairment of these stress pathways could be linked to chronic diseases will improve understanding of the causes of individual variations in susceptibility and the contribution of habituation/learning and resiliency. This review highlights effects of air pollution in the respiratory tract that impact the brain and neuroendocrine system, including the role of autonomic sensory nervous system in triggering neural stress response, the likely contribution of translocated nano particles or metal components, and biological mediators released systemically in causing effects remote to the respiratory tract. The perspective on the use of systems approaches that incorporate multiple chemical and non-chemical stressors, including environmental, physiological and psychosocial, with the assessment of interactive neural mechanisms and peripheral networks are emphasized.

Maternal affective and stress-related factors during pregnancy affect the occurrence of childhood allergic diseases: A Shanghai MCPC study

OBJECTIVE

To investigate the association between exposures to maternal affective and stress-related factors during pregnancy and allergies in children from birth to 2 years of age.

METHODS

We enrolled a total of 4178 children from the Shanghai Maternal-Child Pairs Cohort and measured maternal stress, anxiety, and depression during pregnancy by applying the Life Events Scale for Pregnant Women, Self-Rating Anxiety Scale, and the Center for Epidemiologic Studies-Depression Scale, respectively. Children's allergies were assessed by community physicians at 2, 6, 12, and 24 months, respectively; these included eczema, atopic dermatitis, food allergy, wheezing, asthma, and atopic rhinitis. We applied a latent class analysis (LCA) to these factors and analyzed the impacts of maternal affective and stress-related factors on childhood allergies by exploiting multivariate logistic regression.

RESULTS

Three distinct classes of children were revealed by LCA: healthy (79.8%), transient allergy (15.2%), and persistent allergy (4.9%). High maternal stress in both early and late pregnancy was associated with an increased risk of infant eczema at 2 months (aOR = 1.30, 95% CI = 1.01-1.67; aOR = 1.64, 95% CI = 1.14-2.36). Moreover, high maternal stress in late pregnancy was also associated with food allergy at 6 months, rhinitis at 2 years of age, and persistent allergy (aOR = 3.22, 95% CI = 1.27-8.12; aOR = 1.78, 95% CI = 1.01-3.15; and aOR = 1.93, 95% CI = 1.10-3.40).

CONCLUSIONS

The associations of maternal affective and stress-related factors during pregnancy with childhood allergies may vary by type and disease onset. We postulate that maternal stress in late pregnancy may exert a sustained negative effect on early childhood allergic diseases.

Preconception stress exposure from childhood to adolescence and birth outcomes: The impact of stress type, severity and consistency

The negative effects of prenatal stress on offspring health are well established, but there remains little understanding of the influence of stress prior to conception despite known effects on biological systems that are important for a healthy pregnancy. Furthermore, operational definitions of stress vary considerably, and exposure is often characterized via summed, ordinal scales of events. We hypothesized that type, severity, and consistency of preconception stress would be associated with birthweight and gestational age (GA) at birth. Data were drawn from a subsample of participants in the 21-year longitudinal Pittsburgh Girls Study (PGS, N = 2,450) that has followed women annually since childhood. Prior work in the PGS derived three domains of stress exposure between ages 7-17 years related to subsistence (e.g., resource strain, overcrowding), safety (e.g., community violence, inter-adult aggression), and caregiving (e.g., separation, maternal depression). We tested the effects of dimensions of preconception stress on birthweight and GA among offspring of 490 PGS participants who delivered at age 18 or older (n = 490; 76% Black, 20% White, 4% Multiracial). Our hypotheses were partially supported with results varying by stress type and severity and by infant sex. Severity of preconception exposure to subsistence stress was prospectively associated with lower offspring birthweight (B = -146.94, SE = 69.07, 95% CI = -282.66, -11.22). The association between severity of caregiving stress in childhood and adolescence and GA at birth was moderated by infant sex (B = 0.85, SE = .41, 95% CI = 0.04, 1.66), suggesting greater vulnerability to this type of stress for male compared to female infants. Exposure to safety stressors did not predict birth outcomes. Infants of Black compared with White mothers had lower birthweight in all models regardless of preconception stress type, severity or consistency. However, we observed no moderating effects of race on preconception stress-birth outcome associations. Demonstrating specificity of associations between preconception stress exposure and prenatal health has the potential to inform preventive interventions targeting profiles of exposure to optimize birth outcomes.

Life Course of Asthma

Asthma is a heterogeneous chronic airway disease that can vary over a lifetime. Although broad categories of asthma by severity and type have been constructed, there remains a tremendous opportunity to discover an approach to managing asthma with additional factors in mind. Many in the field have suggested and are pursuing a novel paradigm shift in how asthma might be better managed, considering the life course of exposures, management priorities, and predicted trajectory of lung function growth. This approach will require a more holistic view of prenatal, postnatal, adolescence, hormonal and gender aspects, and the aging process. In addition, the environment, externally and internally, including in one's genetic code and epigenetic changes, are factors that affect how asthma progresses or becomes more stable in individuals. This chapter focuses on the various influences that may, to differing degrees, affect people with asthma, which can develop at any time in their lives. Shifting the paradigm of thought and strategies for care and advocating for public policies and health delivery that focus on this philosophy is paramount to advance asthma care for all.

Longitudinal assessment of maternal depression and early childhood asthma and wheeze: Effect modification by child sex

BACKGROUND

Studies report associations between maternal mental health and adverse respiratory outcomes in children; however, the impact of timing and duration of maternal distress remains understudied. We sought to longitudinally examine associations between maternal depression and childhood asthma and wheeze, and explore sex differences.

METHODS

Maternal depression (n = 601) was assessed using the Edinburgh Depression Scale questionnaire, dichotomized at a clinically relevant cutoff (>12) (a) during pregnancy, (b) postpartum, and (c) postpartum and subsequent time points postnatally (recurrent depression). Report of wheeze in the past 12 months (current wheeze) and asthma were obtained using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire at 48 and 72 months. Associations were analyzed using a modified Poisson regression adjusted for covariates, and in interaction models.

RESULTS

Both postpartum and recurrent depression were associated with higher risk of current wheeze (relative risk [RR]: 1.87, 95% confidence interval [CI]: 1.21, 2.90; RR: 2.41, 95% CI: 1.53, 3.79) and asthma at 48 months (RR: 2.42, 95% CI: 1.01, 5.84; RR: 2.45, 95% CI: 1.02, 5.84). In interaction analyses, associations were stronger in females. Recurrent depression was associated with a higher risk of current wheeze at 48 months in females (RR: 4.34, 95% CI: 2.02, 9.32) when compared to males (RR: 1.89, 95% CI: 1.05, 3.39).

CONCLUSIONS

Postpartum and recurrent depression were associated with a higher risk of wheeze and asthma in children. Understanding the temporal- and sex-specific effects of maternal depression may better inform prevention strategies.

Air pollution and pediatric respiratory hospital admissions in Bursa, Turkey: A time series study

We aimed to investigate the relation between air pollution and the number of daily hospitalizations due to pneumonia, asthma, bronchitis in children aged 0-18 in Bursa city of Turkey, between the years 2013-2018. The daily values of air pollutants (PM10, SO2, NO2, NOx, CO, and O3) from 2013 until 2018, were obtained. Adjusted Quasi-Poisson regression models including distributed lags, controlled for climate variables were used for data analysis. Increases in SO2, ozone, PMs, and nitrogen oxides were associated with pneumonia hospitalizations, increases in SO2 NOx and PMs were associated with asthma hospitalizations, and increases in SO2 and ozone were associated with bronchitis hospitalizations. Male hospitalization was related with SO2, ozone, and NOx; while female hospitalization was only related with SO2. This study showed that short-term exposure to air pollution is associated with an increased risk of pneumonia, asthma, and bronchitis hospitalization among children in Bursa.

Characteristics of inpatients with atopic asthma in a tertiary center: Do age and gender have an influence?

Background: Several studies have demonstrated gender influence on asthma prevalence, being higher among males during early childhood. Little is known about the impact of gender and age on asthma exacerbation characteristics in pediatrics. This study aimed to determine the differences in acute asthma between males and females in three different age groups regarding perinatal characteristics of asthmatic patients, comorbidities, medication adherence, level of blood eosinophils, and pattern of hospitalization.Methods: The medical records of 130 pediatric patients with asthma, who presented to the emergency department at Jordan University hospital with asthma exacerbations, were retrospectively reviewed. Demographic information and clinical characteristics were collected.Results: The mean age of patients was 10.7±4.7 years. The age at diagnosis and gestational age were significantly higher in older children. Furthermore, younger children were significantly more likely to experience winter exacerbations and more emergency presentations. Male patients were considerably younger than their female counterparts and were diagnosed younger. In addition, male patients were more likely to have eosinophil levels higher than 3% than female patients.Conclusion: Gender plays a role in the development and outcome of asthma exacerbations at different ages of pediatrics. A better understanding of gender-based and age-based differences in asthma dictates a personalized approach to treatment.

Human Milk Extracellular Vesicles: A Biological System with Clinical Implications

The consumption of human milk by a breastfeeding infant is associated with positive health outcomes, including lower risk of diarrheal disease, respiratory disease, otitis media, and in later life, less risk of chronic disease. These benefits may be mediated by antibodies, glycoproteins, glycolipids, oligosaccharides, and leukocytes. More recently, human milk extracellular vesicles (hMEVs) have been identified. HMEVs contain functional cargos, i.e., miRNAs and proteins, that may transmit information from the mother to promote infant growth and development. Maternal health conditions can influence hMEV composition. This review summarizes hMEV biogenesis and functional contents, reviews the functional evidence of hMEVs in the maternal–infant health relationship, and discusses challenges and opportunities in hMEV research.

S3 guideline Allergy Prevention

BACKGROUND

The persistently high prevalence of allergic diseases in Western industrial nations and the limited possibilities of causal therapy make evidence-based recommendations for primary prevention necessary.

METHODS

The recommendations of the S3 guideline Allergy Prevention, published in its last version in 2014, were revised and consulted on the basis of a current systematic literature search. The evidence search was conducted for the period 06/2013 - 11/2020 in the electronic databases Cochrane and MEDLINE, as well as in the reference lists of current reviews and through references from experts. The literature found was screened in two filtering processes, first by title and abstract, and the remaining papers were screened in the full text for relevance. The studies included after this were sorted by level of evidence, and the study quality was indicated in terms of potential bias (low/high). The revised recommendations were formally agreed and consented upon with the participation of representatives of the relevant professional societies and (self-help) organizations (nominal group process). Of 5,681 hits, 286 studies were included and assessed.

RESULTS

Recommendations on maternal nutrition during pregnancy and breastfeeding as well as on infant nutrition in the first months of life again play an important role in the updated guideline: Many of the previous recommendations were confirmed by the current data. It was specified that breastfeeding should be exclusive for the first 4 - 6 months after birth, if possible, and that breastfeeding should continue with the introduction of complementary foods. A new recommendation is that supplementary feeding of cow's milk-based formula should be avoided in the first days of life if the mother wishes to breastfeed. Furthermore, it was determined that the evidence for a clear recommendation for hydrolyzed infant formula in non-breastfed infants at risk is currently no longer sufficient. It is therefore currently recommended to check whether an infant formula with proven efficacy in allergy prevention studies is available until the introduction of complementary feeding. Finally, based on the EAACI guideline, recommendations were made for the prevention of chicken egg allergy by introducing and regularly giving thoroughly heated (e.g., baked or hard-boiled) but not "raw" chicken egg (also no scrambled egg) with the complementary food. The recommendation to introduce peanut in complementary feeding was formulated cautiously for the German-speaking countries: In families who usually consume peanut, the regular administration of peanut-containing foods in age-appropriate form (e.g., peanut butter) with the complementary diet can be considered for the primary prevention of peanut allergy in infants with atopic dermatitis (AD). Before introduction, a clinically relevant peanut allergy must be ruled out, especially in infants with moderate to severe AD. There is still insufficient evidence for an allergy-preventive efficacy of prebiotics or probiotics, vitamin D, or other vitamins in the form of supplements so that recommendations against their supplementation were adopted for the first time in the current guideline. Biodiversity plays an important role in the development of immunological tolerance to environmental and food allergens: there is clear evidence that growing up on a farm is associated with a lower risk of developing asthma and allergic diseases. This is associated with early non-specific immune stimulation due to, among other things, the greater microbial biodiversity of house dust in this habitat. This aspect is also reflected in the recommendations on animal husbandry, on which a differentiated statement was made: In families without a recognizable increased allergy risk, pet keeping with cats or dogs should not generally be restricted. Families with an increased allergy risk or with children with already existing AD should not acquire a new cat - in contrast, however, dog ownership should not be discouraged. Interventions to reduce exposure to dust mite allergens in the home, such as the use of mite allergen-proof mattress covers ("encasings"), should be restricted to patients with already proven specific sensitization against house dust mite allergen. Children born by caesarean section have a slightly increased risk of asthma - this should be taken into account when advising on mode of delivery outside of emergency situations. Recent work also supports the recommendations on air pollutants: Active and passive exposure to tobacco smoke increase the risk of allergies, especially asthma, and should therefore be avoided. Exposure to nitrogen oxides, ozone, and small particles (PM 2.5) is associated with an increased risk, especially for asthma. Therefore, exposure to emissions of nitrogen oxides, ozone, and small particles (PM 2.5) should be kept low. The authors of this guideline are unanimously in favor of enacting appropriate regulations to minimize these air pollutants. There is no evidence that vaccinations increase the risk of allergies, but conversely there is evidence that vaccinations can reduce the risk of allergies. All children, including children at risk, should be vaccinated according to the current recommendations of the national public health institutes, also for reasons of allergy prevention.

CONCLUSION

The consensus of recommendations in this guideline is based on an extensive evidence base. The update of the guideline enables evidence-based and up-to-date recommendations for the prevention of allergic diseases including asthma and atopic dermatitis.

Sex and gender in asthma

Asthma is a heterogenous disease, and its prevalence and severity are different in males versus females through various ages. As children, boys have an increased prevalence of asthma. As adults, women have an increased prevalence and severity of asthma. Sex hormones, genetic and epigenetic variations, social and environmental factors, and responses to asthma therapeutics are important factors in the sex differences observed in asthma incidence, prevalence and severity. For women, fluctuations in sex hormone levels during puberty, the menstrual cycle and pregnancy are associated with asthma pathogenesis. Further, sex differences in gene expression and epigenetic modifications and responses to environmental factors, including SARS-CoV-2 infections, are associated with differences in asthma incidence, prevalence and symptoms. We review the role of sex hormones, genetics and epigenetics, and their interactions with the environment in the clinical manifestations and therapeutic response of asthma.

Early Adverse Experiences and Repeated Wheezing From 6 to 30 Months of Age: Investigating the Roles of Hypothalamic-Pituitary-Adrenal Axis Functioning, Child Sex, and Caregiving Sensitivity

This study examined associations among early adversity, diurnal cortisol, child sex, and caregiver sensitivity at age 6 months in relation to wheezing in children (47% male) followed to 30 months. Analyses included 676 mother-child dyads, 393 of whom completed an observational caregiver sensitivity measure. Participants were primarily ethnic minorities (42.7% Black, 25.4% Hispanic); 22.1% of children had ≥ 1 wheezing episode. Higher adversity was associated with increased wheeze frequency and blunted diurnal cortisol slope. The indirect effect of adversity on wheezing through cortisol slope was significant for females, but not males. Higher caregiver sensitivity was protective against wheezing for males, but not females, with high cortisol. Findings suggest complex associations among adversity, cortisol, child sex, and caregiver sensitivity in predicting wheezing.

Prenatal PM2.5 affects atopic dermatitis depending on maternal anxiety and gender: COCOA study

BACKGROUND

The prevalence of atopic dermatitis (AD) is increasing worldwide. Prenatal particulate matter with an aerodynamic diameter <2.5 μm (PM2.5) and maternal anxiety during pregnancy has been suggested as a potential causes of AD. This study investigated the effects of prenatal PM2.5 and maternal anxiety on AD and identified the critical period of PM2.5 exposure for AD in infants.

METHODS

This study included 802 children from the COCOA birth cohort study with follow-up data at 1 year of age. PM2.5 was estimated by land-use regression models and prenatal anxiety was measured with a questionnaire. AD was diagnosed by doctor at 1 year of age. Logistic regression analysis and Bayesian distributed lag interaction models were applied.

RESULTS

Higher PM2.5 during the first trimester of pregnancy, higher prenatal maternal anxiety, and male gender were associated with AD at 1 year of age (adjusted odds ratio [aOR] and 95% confidence interval [CI]: 1.86 [1.08-3.19], 1.58 [1.01-2.47], and 1.54 [1.01-2.36], respectively). Higher PM2.5 during the first trimester and higher maternal anxiety during pregnancy showed an additive effect on the risk of AD (aOR: 3.13; 95% CI: 1.56-6.28). Among boys exposed to higher maternal anxiety during pregnancy, gestational weeks 5-8 were the critical period of PM2.5 exposure for the development of AD.

CONCLUSIONS

Higher PM2.5 exposure during gestational weeks 5-8 increased the probability of AD in infancy, especially in boys with higher maternal anxiety. Avoiding PM2.5 exposure and maternal anxiety from the first trimester may prevent infant AD.

Prenatal Neighborhood Ethnocultural Context and the Mental Health of Mothers and Children in Low-Income Mexican American Families

Socioeconomically disadvantaged neighborhoods increase the risk for poor mental health among residents, yet protective factors may operate alongside risk. This study evaluated the influence of the prenatal neighborhood ethnocultural context on child behavior problems and maternal depressive symptoms. Prenatal maternal role expectations, prenatal culture-specific stress, and postpartum depression (PPD) symptoms were evaluated as mediators. Participants included 322 low-income, Mexican American mother-child dyads. Women (Mage  = 27.8) reported on proposed mediators, maternal depressive symptoms, and child behavior problems at 4.5 years. Neighborhood Latinx concentration was obtained from census data. Higher Latinx concentration predicted fewer maternal depressive symptoms and child behavior problems, mediated through role expectations and PPD symptoms. Results suggest prenatal neighborhood context to impact later maternal and child mental health.

Parental occupational exposure pre- and post-conception and development of asthma in offspring

Background

While direct effects of occupational exposures on an individual’s respiratory health are evident, a new paradigm is emerging on the possible effects of pre-conception occupational exposure on respiratory health in offspring. We aimed to study the association between parental occupational exposure starting before conception and asthma in their offspring (at 0–15 years of age).

Methods

We studied 3985 offspring participating in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study. Their mothers or fathers (n = 2931) previously participated in the European Community Respiratory Health Survey (ECRHS). Information was obtained from questionnaires on parental job history pre- and post-conception which was linked to an asthma-specific job-exposure matrix (JEM). We assessed the association between parental occupational exposure and offspring asthma, applying logistic regression models, clustered by family and adjusted for study centre, offspring sex, parental characteristics (age, asthma onset, place of upbringing, smoking) and grandparents’ level of education.

Results

Parental occupational exposure to microorganisms, pesticides, allergens or reactive chemicals pre-conception or both pre- and post-conception was not related to offspring asthma; in general, subgroup analyses confirmed this result. However, maternal exposure both pre- and post-conception to allergens and reactive chemicals was associated with increased odds for early-onset asthma in offspring (0–3 years of age); odds ratio 1.70 (95% CI: 1.02–2.84) and 1.65 (95% CI: 0.98–2.77), respectively.

Conclusions

This study did not find evidence that parental occupational exposure, defined by an asthma JEM before conception only or during pre- and post-conception vs non-exposed, was associated with offspring asthma.

Maternal life and work stressors during pregnancy and asthma in offspring

Background

Maternal stressors during pregnancy are potential risk factors for asthma in offspring. However, previous studies have been limited by the use of self-reported data focusing on stressors either in private life or at work. This study examined the association between maternal stressors both in private life and at work during pregnancy and asthma in offspring.

Methods

In the Danish National Birth Cohort, 75 156 live-born singletons born during 1996–2002 were identified. Maternal information on job title were available around weeks 12–16 of gestation. Data on maternal bereavement, life-threatening illness, suicide attempt and alcohol or drug abuse of a close relative and offspring childhood asthma (3–10 years of age) were obtained from Danish nationwide registers. Maternal psychosocial work stressors (job control, psychological job demands, emotional job demands, work-related violence and threats of work-related violence) were estimated by the use of job-exposure matrices. The association between maternal stress and childhood asthma was analysed in Cox models adjusted for maternal age, comorbidity and parity.

Results

Neither private-life nor work stressors were related to onset of asthma in offspring. Separate analyses by parental atopy or onset of asthma in offspring supported the main findings.

Conclusions

This study does not support an elevated risk of childhood asthma related to exposure to stress during pregnancy.

A model of perinatal stress and childhood wheezing: ELSPAC-CZ cohort

BACKGROUND

Prenatal origins of wheezing are not fully understood. This study develops a model of mechanisms linking perinatal stress exposure to wheeze phenotypes in children.

METHODS

Data were obtained from 1880 mother-child dyads participating in ELSPAC-CZ birth cohort. Wheeze phenotypes assessed between birth and age 7 years included "never wheeze," "early-onset transient (EOT) wheeze," "early-onset persistent (EOP) wheeze," and "late-onset (LO) wheeze." Prenatal and postnatal stress exposures were assessed in mid-pregnancy and 6 months after delivery, respectively, using an inventory of 42 life events.

RESULTS

In adjusted models, children in the highest tercile (high) versus lowest tercile (low) for prenatal life events had a 38% higher risk of EOT wheeze (relative risk ratio [RRR] = 1.38; 95% confidence interval [CI] = 1.01-1.88; p = .041) and 50% higher risk of LO wheeze (RRR = 1.50; 95% CI = 1.00-2.25; p = .047). High versus low exposure to postnatal life events predicted a 60% increase in relative risk of EOT wheeze (RRR = 1.60; 95% CI = 1.17-2.19; p = .003) and medium versus low exposure was related to an 85% increase in relative risk of EOP wheeze (RRR = 1.85; 95% CI = 1.16-2.95; p = .010). Lower respiratory tract infections and postpartum depression partially mediated between postnatal life events and any wheeze (indirect effects 1.06, 95% CI = 1.02-1.09, p = .003 and odds ratio [OR] = 1.08, 95% CI = 1.02-1.15, p = .012, respectively), while postnatal events mediate for prenatal events (indirect effect OR = 1.11; 95% CI = 1.03-1.18; p = .005).

CONCLUSIONS

Exposures to prenatal and postnatal life events are risk factors for the development of wheezing. Prenatal stress contributes to wheeze directly and also through postnatal life events, respiratory infections, and maternal depression.

Associations between maternal lifetime stressors and negative events in pregnancy and breast milk-derived extracellular vesicle microRNAs in the programming of intergenerational stress mechanisms (PRISM) pregnancy cohort

Maternal stress is associated with adverse child health. Breast milk microRNAs encapsulated in extracellular vesicles (EVs) are involved in mother-infant biochemical communication during early-life programming. We leverage the PRogramming of Intergenerational Stress Mechanisms (PRISM) pregnancy cohort to investigate associations between maternal stress and breast milk EV-microRNAs. Lifetime stress and negative life events (NLEs) during pregnancy were assessed using the Life Stressor Checklist-Revised (LSCR) and the Crisis in Family Systems-Revised surveys, respectively. RNA was extracted from breast milk EVs (N = 80; collected 6.1 ± 5.9 weeks postnatally), and microRNAs were profiled using the TaqMan OpenArray Human miRNA panel. Associations between stress scores and detection (yes/no) of 173 microRNAs identified in 20-80% of samples were assessed using logistic regression; associations with expression levels of 205 EV-microRNAs identified in >50% of samples were assessed using linear regression. In adjusted models, detection of 60 and 44 EV-microRNAs was associated with higher LSCR and NLE scores, respectively (p < 0.05). Expression level of 8 and 17 EV-microRNAs was associated with LSCR and NLE scores, respectively, at our a priori criteria of p < 0.05 and |Bregression|>0.2. Enriched KEGG pathways for microRNAs associated with stress scores included fatty acid metabolism and the Hippo signaling pathway. Maternal lifetime stress and NLEs during pregnancy were both associated with detection and expression level of breast milk EV-microRNAs, although associations with microRNA profiles differed between stress measures. Further research is needed to identify biological pathways impacted by associated microRNAs and investigate relationships with child health outcomes.Abbreviations: EV: extracellular vesicle; PRISM: PRogramming of Intergenerational Stress Mechanisms pregnancy cohort; LSCR: Life Stressor Checklist-Revised survey; NLE: negative life event; CRISYS-R: Crisis in Family Systems-Revised survey; KEGG: Kyoto Encyclopaedia of Genes and Genomes; NYC: New York City; SD: standard deviation; IQR: interquartile range; Cq: relative cycle threshold values; PCA: principal component analysis.

Multiple adverse childhood experiences and asthma onset in adulthood: Role of adulthood risk factors as mediators

OBJECTIVE

This population-based study of 21,902 Finnish adults examined whether adulthood risk factors for asthma mediate the association between the exposure to multiple adverse childhood experiences (ACEs) assessed retrospectively and the risk of new-onset asthma in adulthood.

METHODS

Baseline characteristics, occurrence of ACEs, and risk factors of asthma in adulthood were collected with a postal survey at baseline in 1998. The participants were linked to records on incident asthma from national health registers from 1999 to 2012. Counterfactual mediation analysis was used to examine the effects of multiple ACEs (≥2) on asthma through adulthood risk factors of asthma (mediators).

RESULTS

Of the 21,902 participants without asthma at baseline, 7552 (34%) were exposed to multiple ACEs during childhood. During the follow-up period, 2046 participants were diagnosed with incident asthma. Exposure to multiple ACEs increased the risk of asthma onset by 31% compared with ≤1 ACE. The association between ACEs and asthma onset was partly mediated by the following adulthood risk factors: severe life events (29%), smoking (15%), allergic rhinitis (8%), low education level (6%), and obesity (3%). Specific stressful life events mediating the ACE-asthma association were 'severe financial difficulties' (24%), 'emotional, physical or sexual violence' (15%), 'major increase in marital problems' (8%), 'severe conflicts with supervisor' (7%), and 'divorce or separation' (5%).

CONCLUSIONS

Exposure to multiple ACEs increased the risk of asthma in adulthood. Adulthood risk factors of asthma mediated a significant proportion of the effect of ACEs on the risk of asthma onset.

Adverse childhood experiences and asthma: trajectories in a national cohort

Objective

Research has linked early adverse childhood experiences (ACEs) with asthma development; however, existing studies have generally relied on parent report of exposure and outcome. We aimed to examine the association of early life ACEs with empirically determined trajectories of childhood asthma risk, using independent register information on both exposures and outcome.

Methods

Based on nationwide registries, we established a study cohort of 466 556 children born in Denmark (1997–2004). We obtained information on ACEs during the first 2 years of life (bereavement, parental chronic somatic and/or mental illness) and childhood asthma diagnosis or medication use from birth through age 10 years from the Danish National Patient and Prescription Registries, respectively. We identified asthma phenotypes using group-based trajectory modelling. We then used multinomial logistic regression to examine the association between early ACEs and asthma phenotypes.

Results

We identified four asthma phenotypes: non-asthmatic, early-onset transient, early-onset persistent and late-onset asthma. Girls with early-onset transient asthma (OR 1.13, 95% CI 1.04 to 1.24), early-onset persistent asthma (1.27, 95% CI 1.08 to 1.48) or late-onset asthma (OR 1.28, 95% CI 1.11 to 1.48) vs no asthma were more likely to have early life ACE exposure compared with girls without ACE exposure. Results were similar for boys who also had experienced early life ACEs with ORs of 1.16 (95% CI 1.08 to 1.25), 1.34 (95% CI 1.20 to 1.51) and 1.11 (95% CI 0.98 to 1.25), respectively.

Conclusion

In a nationwide-population study, we identified three childhood onset asthma phenotypes and found that ACEs early in life were associated with increased odds for each of these asthma phenotypes among both girls and boys.

Maternal stress and depression are associated with respiratory phenotypes in urban children

BACKGROUND

Prenatal and early-life exposure to maternal stress and depression is linked to development of recurrent wheezing in young children.

OBJECTIVE

We sought to determine whether maternal stress and depression in early life are associated with nonatopic wheezing phenotype in urban children.

METHODS

The Urban Environment and Childhood Asthma Study examined a birth cohort of children at high risk for asthma in low-income neighborhoods. Prenatal and postnatal (through age 3 years) maternal stress and depression scores were compared with respiratory phenotypes through age 10 years (multinomial regression), self-reported colds (linear regression), and detection of respiratory viruses (Poisson regression).

RESULTS

Scores for maternal depression, and, to a lesser extent, maternal perceived stress, were positively related to multiple wheezing phenotypes. In particular, cumulative measures of maternal depression in the first 3 years were related to the moderate-wheeze-low-atopy phenotype (odds ratio, 1.13; [1.05, 1.21]; P < .01). Considering indicators of respiratory health that were used to identify the phenotypes, there were multiple positive associations between early-life scores for maternal stress and depression and increased wheezing illnesses, but no consistent relationships with lung function and some inverse relationships with allergic sensitization. Cumulative maternal stress and depression scores were associated with cumulative number of respiratory illnesses through age 3 years.

CONCLUSIONS

Among high-risk, urban children, maternal stress and depression in early life were positively associated with respiratory illnesses and a moderate-wheeze-low-atopy phenotype. These results suggest that treating stress and depression in expectant and new mothers could reduce viral respiratory illnesses and recurrent wheeze during the preschool years and some forms of childhood asthma.

Better maternal quality of life in pregnancy yields better offspring respiratory outcomes: A birth cohort

BACKGROUND

It is suggested that maternal mental health during pregnancy may affect offspring immune and respiratory features, based on the developmental origins of health and disease hypothesis.

OBJECTIVE

To evaluate whether maternal quality of life (QoL) and depression during pregnancy leads to wheezing, asthma, and food allergy of the offspring at 3 years of age.

METHODS

We conducted a nationwide, multicenter, prospective birth cohort study, Japan Environment and Children's Study. All variables were collected from questionnaires. Health-related QoL was measured using the Medical Outcomes Survey Short Form-8 questionnaire with a physical component summary and a mental component summary score. We conducted logistic regression analyses to evaluate the associations of offspring's wheezing, asthma, and food allergy with maternal QoL and depression.

RESULTS

There were 72,685 participants with no missing variables. Maternal physical component summary scores of the Medical Outcomes Survey Short Form-8 questionnaire were negatively associated with offspring's asthma (adjusted odds ratio [aOR], 0.99; 95% confidence interval [CI], 0.99-1.00), current wheezing (aOR, 0.99; 95% CI, 0.99-0.99), and food allergy diagnoses (aOR, 0.99; 95% CI, 0.98-0.99) in children. Offspring's wheezing and asthma were also associated with maternal depression and anxiety during pregnancy.

CONCLUSION

Poor maternal prenatal QoL increased the risk of wheezing, asthma, and food allergy in offspring. In addition, maternal depression and anxiety increased the risk of offspring's wheezing, asthma, and food allergy.

Parents' Acceptance of Learning about Mindfulness for Managing Pediatric Asthma

Background: Emerging research suggests mindfulness may reduce stress and asthma symptoms in children, yet there is a gap in understanding parental views towards learning about mindfulness. Objective: This study aimed to compare the perceived acceptance to learn about mindfulness among parents of children with and without asthma, and to understand differences across income levels. Methods: This was a national, cross-sectional, online survey of parents of children 0–18 years. Acceptance was measured with questions on whether parents believe mindfulness could be beneficial while parenting, and if they would be willing to learn about mindfulness. Comparisons of mindfulness acceptance between income level were conducted using chi-square and Fisher’s exact test. Results: Parents of children with asthma were more likely to be interested in learning about mindfulness from their health care provider compared to those without asthma (46% vs. 38%, p < 0.0001). At all income levels examined in the study, parents (63–75%) of children with asthma indicated that they agreed or strongly agreed that mindfulness can be beneficial when parenting. Conclusion: Findings suggest an opportunity to incorporate mindfulness teaching into asthma care for pediatric patients of all income levels.

Maternal anxiety and depression in pregnancy and DNA methylation of the NR3C1 glucocorticoid receptor gene

Aim: To quantify associations of anxiety and depression during pregnancy with differential cord blood DNA methylation of the glucorticoid receptor ( NR3C1). Materials & methods: Pregnancy anxiety, trait anxiety and depressive symptoms were collected using the Pregnancy Related Anxiety Scale, State-Trait Anxiety Index and Edinburgh Postnatal Depression Scale, respectively. NR3C1 methylation was determined at four methylation sites. Results: DNA methylation of CpG 1 in the NR3C1 CpG island shore was higher in infants born to women with high pregnancy anxiety (β 2.54, 95% CI: 0.49–4.58) and trait anxiety (β 1.68, 95% CI: 0.14–3.22). No significant association was found between depressive symptoms and NR3C1 methylation. Conclusion: We found that maternal anxiety was associated with increased NR3C1 CpG island shore methylation.

Consequences of maternal psychological stress during pregnancy for the risk of asthma in the offspring

Asthma is a common lung condition that makes breathing difficult through the inflammation and constriction of the lung airways. Epidemiological evidence supports the presence of a positive association between prenatal maternal psychological stress (PMPS) and asthma in the offspring, suggesting the disease may have developmental origins. T-helper 2 (Th2) cells are a major subtype of T-helper cells, producing Th2 cytokines, which may be the main drivers of asthma symptoms. A Th2 dominant blood cytokine profile may therefore indicate an increased risk of asthma, as studies have shown a link between PMPS and a T-helper 2 (Th2) cytokine profile in offspring. The mechanism by which PMPS may cause Th2 cytokine dominance in the offspring is unclear. Epigenetic modifications in utero can lead to long-lasting effects that persist postnatally and have therefore been implicated in this relationship. Increased maternal blood cortisol levels due to PMPS may increase transfer of cortisol to the foetus, where the temporarily increased levels may induce changes in the epigenome. Evidence from animal studies suggests that genes controlling cytokine production in T cells can be epigenetically modified in a way that increases Th2 cytokine production. Other evidence suggests that methylation of the NR3C1 gene decreases hippocampal glucocorticoid receptor expression, leading to decreased negative regulation of the hypothalamus-pituitary-adrenal axis. This can increase cortisol production which has been shown to increase Th2 cytokine production. Therefore, the link between PMPS and a Th2 offspring cytokine profile, mediated through epigenetic changes, may explain the positive relationship between PMPS and asthma in the offspring.

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

BACKGROUND

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

OBJECTIVE AND RATIONALE

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

SEARCH METHODS

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

OUTCOMES

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

WIDER IMPLICATIONS

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

A prenatally disrupted airway epithelium orchestrates the fetal origin of asthma in mice

BACKGROUND

Prenatal challenges such as maternal stress perception increase the risk and severity of asthma during childhood. However, insights into the trajectories and targets underlying the pathogenesis of prenatally triggered asthma are largely unknown. The developing lung and immune system may constitute such targets.

OBJECTIVE

Here we have aimed to identify the differential sex-specific effects of prenatal challenges on lung function, immune response, and asthma severity in mice.

METHODS

We generated bone marrow chimeric (BMC) mice harboring either prenatally stress-exposed lungs or a prenatally stress-exposed immune (hematopoietic) system and induced allergic asthma via ovalbumin. Next-generation sequencing (RNA sequencing) of lungs and assessment of airway epithelial barrier function in ovalbumin-sensitized control and prenatally stressed offspring was also performed.

RESULTS

Profoundly enhanced airway hyperresponsiveness, inflammation, and fibrosis were exclusively present in female BMC mice with prenatally stress-exposed lungs. These effects were significantly perpetuated if both the lungs and the immune system had been exposed to prenatal stress. A prenatally stress-exposed immune system alone did not suffice to increase the severity of these asthma features. RNA sequencing analysis of lungs from prenatally stressed, non-BMC, ovalbumin-sensitized females unveiled a deregulated expression of genes involved in asthma pathogenesis, tissue remodeling, and tight junction formation. It was also possible to independently confirm a tight junction disruption. In line with this, we identified an altered perinatal and/or postnatal expression of genes involved in lung development along with an impaired alveolarization in female prenatally stressed mice.

CONCLUSION

Here we have shown that the fetal origin of asthma is orchestrated by a disrupted airway epithelium and further perpetuated by a predisposed immune system.

Maternal Distress During Pregnancy and Recurrence in Early Childhood Predicts Atopic Dermatitis and Asthma in Childhood

BACKGROUND

Early-life stress is becoming an important determinant of immune system programming. Maternal prenatal distress is found to be associated with atopic disease in offspring but the separate effects of postnatal distress are not well-studied.

RESEARCH QUESTION

Does the likelihood of asthma and atopic dermatitis in children increase when they are exposed to maternal distress pre- and postnatally in a sex-specific manner?

STUDY DESIGN AND METHODS

Using data from a provincial newborn screen and health-care database for 12,587 children born in 2004, maternal distress (depression or anxiety) was defined as prenatal, self-limiting, recurrent, or late-onset postpartum. Atopic dermatitis (AD) and asthma at ages 5 years and 7 years of age were diagnosed by using hospitalization, physician visit, or prescription records. Associations between maternal distress and childhood asthma and AD were determined by using multiple logistic regression.

RESULTS

After adjusting for risk factors, a significant association between maternal prenatal (OR, 1.27; 95% CI, 1.11-1.46), recurrent postpartum (OR, 1.28; 95% CI, 1.11-1.48), and late-onset postpartum (OR, 1.19, 95% CI, 1.06-1.34) distress was found with AD at age 5 years. Asthma at age 7 years was also associated with maternal prenatal distress (OR, 1.57; 95% CI, 1.29-1.91) and late-onset postnatal distress (OR, 1.22; 95% CI, 1.01-1.46). Self-limiting postnatal distress was not found to be a risk factor for either atopic condition. Associations with AD or asthma were of a similar magnitude in boys and girls; the exception was recurrent postnatal distress, which increased risk for asthma in boys only.

INTERPRETATION

This population-based study provides evidence for sex-specific associations between maternal prenatal and postnatal distress, as well as the development of AD and asthma. The findings support recommendations for greater psychosocial support of mothers during pregnancy and early childhood to prevent childhood atopic disease.

Chronic, Elevated Maternal Corticosterone During Pregnancy in the Mouse Increases Allergic Airway Inflammation in Offspring

Allergic asthma is a chronic pulmonary disorder fundamentally linked to immune dysfunction. Since the immune system begins developing in utero, prenatal exposures can affect immune programming and increase risk for diseases such as allergic asthma. Chronic psychosocial stress during pregnancy is one such risk factor, having been associated with increased risk for atopic diseases including allergic asthma in children. To begin to define the underlying causes of the association between maternal stress and allergic airway inflammation in offspring, we developed a mouse model of chronic heightened stress hormone during pregnancy. Continuous oral administration of corticosterone (CORT) to pregnant mice throughout the second half of pregnancy resulted in an ~2-fold increase in circulating hormone in dams with no concomitant increase in fetal circulation, similar to the human condition. To determine how prolonged heightened stress hormone affected allergic immunity in offspring, we induced allergic asthma with house dust mite (HDM) and examined the airway immune response to allergen. Female mice responded to HDM more frequently and had a more robust immune cell response compared to their male counterparts, irrespective of maternal treatment. Male offspring from CORT-treated dams had a greater number of inflammatory cells in the lung in response to HDM compared to males from control dams, while maternal treatment did not affect immune cell numbers in females. Alternatively, maternal CORT caused enhanced goblet cell hyperplasia in female offspring following HDM, an effect that was not observed in male offspring. In summary, prenatal exposure to mild, prolonged heightened stress hormone had sexually dimorphic effects on allergic inflammation in airways of adult offspring.

Proximity to major roadways and asthma symptoms in the School Inner-City Asthma Study

BACKGROUND

Traffic proximity has been associated with adverse respiratory health outcomes. Less is known about the combined impact of residential and school exposures on pediatric asthma.

OBJECTIVE

We sought to use spatial analysis methodology to analyze residential and school proximity to major roadways and pediatric asthma morbidity.

METHODS

The School Inner-City Asthma Study (n = 350) recruited school-aged children with asthma. Each participant's school and home addresses were geocoded, and distances from major roadways were measured to calculate a composite measure accounting for both home and school traffic exposure. Generalized estimating equation models were clustered by subject and adjusted for age, race/ethnicity, sex, income, environmental tobacco smoke, controller medication, upper respiratory tract infections, and seasonality.

RESULTS

The majority of participants (62%) attended schools within 100 m from major roadways, and 40% also resided within 100 m of major roadways. In multivariate analyses major roadway proximity was independently associated with increased asthma symptom days. At greater than the threshold of 100 m, children had 29% less odds of a symptom day over the past 2 weeks for each 100-m increase in distance from a major roadway (odds ratio, 0.71; 95% CI, 0.58-0.87; P < .01). Children farther from a major roadway also had significantly less reported health care use (odds ratio, 0.63; 95% CI, 0.47-0.85; P < .01) and were significantly less likely to have poor asthma control (odds ratio, 0.80; 95% CI, 0.69-0.94; P < .01). There was not a meaningful association between distance to a major roadway and lung function outcomes.

CONCLUSIONS

Proximity to a major roadway, a composite measure of home and school exposure but primarily driven by home exposure, was associated with greater asthma morbidity. More studies are needed to evaluate the independent effect of school distance to a roadway on asthma morbidity.

Applying a biopsychosocial model to inner city asthma: Recent approaches to address pediatric asthma health disparities

Pediatric asthma in inner cities is often severe and children living in these urban locations with socioeconomic disadvantage experience greater asthma morbidity. There are many interconnected risk factors that individually, and in combination, enhance asthma morbidity. These include biologic factors innate to the child, such as genetics and allergen susceptibility, as well as factors related to the family and neighborhood context. The biopsychosocial model can be used to frame these risk factors and develop interventions specific to the inner city. Successful inner city asthma interventions exist and key characteristics include multi-tiered components that operate within the community to coordinate disease management resources between patients, families and health care systems.

Perinatal maternal mental health is associated with both infections and wheezing in early childhood

BACKGROUND

Wheezing and infections are common during infancy, and the role of early-life exposures in their development is still under investigation. We examined associations between maternal mental health in pregnancy and after delivery and subsequent offspring wheezing and infections.

METHODS

We studied 2314 mother-child pairs recruited in the Piccolipiù birth cohort (Italy) from 2011 to 2015. Maternal mental health was assessed in pregnancy and 12 months after delivery via the General Health Questionnaire-12 (GHQ-12). GHQ-12 Likert scores were collapsed into low (below the upper tercile) and high (above). Risk ratios (RR) and 95% confidence intervals (CI) between each combination of scores-during pregnancy and 1 year after delivery-and outcomes were computed by log-binomial regression models.

RESULTS

High scores both in pregnancy and after delivery, compared with low scores in both periods, were associated with wheezing (RR: 1.35; 95% CI: 1.08, 1.69), recurrent (≥2 episodes) wheezing (1.35; 0.99, 1.83), any and recurrent (≥4 episodes) upper respiratory infections (1.20; 1.04, 1.41, and 1.45; 1.07, 1.97, respectively), lower respiratory infections (1.31; 1.08, 1.61), and diarrhea (1.49; 1.23, 1.80). High scores either during pregnancy or 1 year after delivery only were less consistently associated with outcomes.

CONCLUSIONS

Maternal mental health problems extending from pregnancy to the first year after delivery are associated with development of both wheezing and infections. As wheezing is mostly triggered by infections, increased infection susceptibility could represent a possible common biologic mechanism. This study confirms the importance of early-life exposures on childhood health.

Quality of life, salivary cortisol and atopic diseases in young children

Background

Children with atopic disease may have reduced health-related quality of life (QoL) and morning cortisol. Possible links between QoL, morning cortisol and atopic disease are unclear. We aimed to determine if QoL was associated with morning salivary cortisol at two years of age, and if asthma, atopic dermatitis and/or allergic sensitisation influenced this association. Secondarily, we aimed to determine if QoL at one year of age was associated with salivary cortisol one year later.

Methods and findings

The Bronchiolitis All SE-Norway study included infants during hospitalisation for acute bronchiolitis in infancy (bronchiolitis group) and population-based control infants (controls). The present study included all 358 subjects with available Infant Toddler Quality of Life Questionnaire (ITQOL) from parents, consisting of 13 domains and morning salivary cortisol at two years of age. Answers from the same 0–100 score questionnaire, with optimal score 100 nine months after enrolment, was also available for 289 of these children at about one year of age. Recurrent bronchial obstruction was used as an asthma proxy. Atopic dermatitis was defined by Hanifin and Rajka criteria and allergic sensitisation by a positive skin prick test. Due to different inclusion criteria, we tested possible interactions with affiliation groups. Associations between QoL and cortisol were analysed by multivariate analyses, stratified by bronchiolitis and control groups due to interaction from affiliation grouping on results. At two years of age, QoL decreased significantly with decreasing cortisol in 8/13 QoL domains in the bronchiolitis group, but only with General health in the controls. The associations in the bronchiolitis group showed 0.06–0.19 percentage points changes per nmol/L cortisol for each of the eight domains (p-values 0.0001–0.034). The associations remained significant but diminished by independently including recurrent bronchial obstruction and atopic dermatitis, but remained unchanged by allergic sensitisation. In the bronchiolitis group only, 7/13 age and gender adjusted QoL domains in one-year old children were lower with lower cortisol levels at two years of age (p = 0.0005–0.04).

Conclusions

At two years, most QoL domains decreased with lower salivary cortisol among children who had been hospitalised for acute bronchiolitis in infancy, but for one domain only among controls. Recurrent bronchial obstruction and to a lesser extent atopic dermatitis, weakened these associations that nevertheless remained significant. After bronchiolitis, lower QoL in one-year old children was associated with lower salivary cortisol at two years.

Sex-specific regulation of stress-induced fetal glucocorticoid surge by the mouse placenta

Antenatal stress increases the prevalence of diseases in later life, which shows a strong sex-specific effect. However, the underlying mechanisms remain unknown. Maternal glucocorticoids can be elevated by stress and are potential candidates to mediate the effects of stress on the offspring sex-specifically. A comprehensive evaluation of dynamic maternal and placental mechanisms modulating fetal glucocorticoid exposure upon maternal stress was long overdue. Here, we addressed this gap in knowledge by investigating sex-specific responses to midgestational stress in mice. We observed increased levels of maternal corticosterone, the main glucocorticoid in rodents, along with higher corticosteroid-binding globulin levels at midgestation in C57Bl/6 dams exposed to sound stress. This resulted in elevated corticosterone in female fetuses, whereas male offspring were unaffected. We identified that increased placental expression of the glucocorticoid-inactivating enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2; Hsd11b2 gene) and ATP-binding cassette transporters, which mediate glucocorticoid efflux toward maternal circulation, protect male offspring from maternal glucocorticoid surges. We generated mice with an Hsd11b2 placental-specific disruption (Hsd11b2^PKO) and observed moderately elevated corticosterone levels in offspring, along with increased body weight. Subsequently, we assessed downstream glucocorticoid receptors and observed a sex-specific differential modulation of placental Tsc22d3 expression, which encodes the glucocorticoid-induced leucine zipper protein in response to stress. Taken together, our observations highlight the existence of unique and well-orchestrated mechanisms that control glucocorticoid transfer, exposure, and metabolism in the mouse placenta, pinpointing toward the existence of sex-specific fetal glucocorticoid exposure windows during gestation in mice.

Sex-specific association between prenatal life stress exposure and infant pro-inflammatory cytokine levels during acute respiratory infection

BACKGROUND

Prenatal life stress exposure is linked to dysregulated immune function and chronic inflammatory disease in offspring, but we know little about its effects on infant immune response during viral infection.

METHOD

To address this issue, we examined associations between prenatal life stress exposure and infant upper-airway inflammatory markers during acute respiratory infection (ARI) using data from a prospective, population-based birth-cohort study (N = 180). Infant inflammation was measured as a continuous latent factor within a structural equation modeling framework using nasal wash concentrations of interleukin-1β, interleukin-6, and tumor necrosis factor-α. We hypothesized that infants exposed to prenatal life stress would have greater levels of nasal inflammation during ARI and increased risk for ARI-related morbidity in early childhood.

RESULTS

Our findings contradicted these hypotheses and provided evidence of sexually dimorphic effects of prenatal stress exposure on infant immune functioning during ARI. Among boys, but not girls, prenatal stress was negatively associated with nasal inflammation and indirectly associated with both lower ARI severity and reduced likelihood of subsequent ARI-related hospitalization in the 2nd and 3rd years of life.

CONCLUSION

These data suggest that prenatal stress exposure may be beneficial for infant boys in the context of respiratory viral infections; however, it will be critical to determine if these benefits are offset by increased risk for chronic inflammatory diseases in later childhood. As the participants in this cohort are being followed longitudinally through age 8, we will be able to evaluate long-term health outcomes in future studies.

Life Cycle of Childhood Asthma: Prenatal, Infancy and Preschool, Childhood, and Adolescence

Asthma is a heterogeneous developmental disorder influenced by complex interactions between genetic susceptibility and exposures. Wheezing in infancy and early childhood is highly prevalent, with a substantial minority of children progressing to established asthma by school age, most of whom are atopic. Adolescence is a time of remission of symptoms with persistent lung function deficits. The transition to asthma in adulthood is not well understood.

Maternal Lifetime Trauma and Birthweight: Effect Modification by In Utero Cortisol and Child Sex

OBJECTIVES

To evaluate associations between maternal lifetime traumatic stress and offspring birthweight and examine modifying effects of third trimester cortisol and fetal sex.

STUDY DESIGN

Analyses included 314 mother-infant dyads from an ethnically mixed pregnancy cohort. Maternal lifetime trauma was reported via the Life Stressor Checklist-Revised. Fenton birthweight for gestational age z-scores (BWGA-z) were calculated. A 3-cm scalp-nearest maternal hair segment collected at birth was assayed to reflect cumulative third trimester cortisol secretion. Multivariable regression was used to investigate associations between maternal lifetime trauma and BWGA-z and examine 2- and 3-way interactions with cortisol and fetal sex. Because subjects with low or high cortisol levels could represent susceptible populations, varying coefficient models that relax the linearity assumption on cortisol level were used to assess the modification of maternal lifetime trauma associations with BWGA-z as a function of cortisol.

RESULTS

Women were primarily minorities (41% Hispanic, 26% black) with ≤12 years education (63%); 63% reported ≥1 traumatic event. Prenatal cortisol modified the association between maternal lifetime trauma and birthweight. Women with higher lifetime trauma and increased cortisol had significantly lower birthweight infants in males; among males exposed to the 90th percentile of cortisol, a 1-unit increase in trauma score was associated with a 0.19-unit decrease in BWGA-z (95% CI, -0.34 to -0.04). Associations among females were nonsignificant, regardless of cortisol level.

CONCLUSIONS

These findings underscore the need to consider complex interactions among maternal trauma, disrupted in utero cortisol production, and fetal sex to fully elucidate intergenerational effects of maternal lifetime trauma.