Maternal life and work stressors during pregnancy and asthma in offspring

Occupational psychosocial stressors and ergonomic strain during pregnancy and sex-specific risk of childhood asthma

OBJECTIVES

Previous studies have indicated that maternal occupational psychosocial stressors may affect the risk of asthma in the offspring, but their results are inconsistent. Maternal occupational ergonomic strain is associated with predictors of fetal lung development, including preterm birth and low birthweight; however, it is not known, whether ergonomic strain during pregnancy is a risk factor for asthma in offspring. The aim was to investigate maternal psychosocial stressors and ergonomic strain during pregnancy relative to the risk of offspring asthma.

METHODS

Live- and firstborn singletons (1996-2018) and their mothers were identified from Danish nationwide registers. Job code at time of conception was assigned to each mother and linked with exposure estimates from job exposure matrices (JEMs) of psychosocial stressors and ergonomic strain. Diagnoses of childhood asthma were retrieved from the Danish National Patient Register. Incidence rate ratios (IRR) of asthma were estimated using Poisson regression; adjusted for maternal asthma, age at conception, socioeconomic position, and body mass index, and calendar year.

RESULTS

Maternal employment in occupations with low decision authority (IRR: 1.08, 95% CI 1.00-1.16) and high ergonomic strain (IRR: 1.09, 95% CI 1.02-1.16) was associated with increased risk of asthma among male offspring. Largely similar, but less consistent, associations were observed among female offspring due to low decision authority.

CONCLUSION

We found a minor increased risk of asthma among offspring whose mothers worked in an occupation with low decision authority or high ergonomic strain, most pronounced among male offspring.

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.

Maternal immune activation mediated prenatal chronic stress induces Th17/Treg cell imbalance may relate to the PI3K/Akt/NF-κB signaling pathway in offspring rats

Maternal immune activation (MIA), defined as elevated levels of inflammatory markers beyond the normal range, can occur due to psychological stress, infection, and other disruptions during pregnancy. MIA affects the immune system development in offspring and increases the risk of immune-related disorders. Limited studies have investigated the effects of prenatal stress on offspring's immune system. In this study, pregnant rats were exposed to chronic unpredictable mild stress (CUMS) during pregnancy, involving seven different stressors. We examined the impact of prenatal stress stimuli on the offspring's immune system and observed activation of the PI3K/Akt/NF-κB signaling pathway, resulting in an imbalance of Th17/Treg cells in the offspring's spleen. Our findings revealed increased plasma levels of corticosterone, IL-1β, and IL-6 in female rats exposed to prenatal stress, as well as elevated serum levels of IL-6 and TNF-α in the offspring. Furthermore, we identified a correlation between cytokine levels in female rats and their offspring. Transcriptome sequencing and qPCR experiments indicated differentially expressed mRNAs in offspring exposed to prenatal stress, which may contribute to the imbalance of Th17/Treg cells through the activation of the Gng3-related PI3K/Akt/NF-κB pathway.