Maternal stressful life events during pregnancy and child asthma: an investigation of effect modification by postnatal neighborhood opportunity

BACKGROUND/AIM: Studies have linked prenatal maternal psychosocial stress and childhood wheeze/asthma, but have rarely investigated modifiable factors that may mitigate risks such as the postnatal environment. We investigated associations between prenatal stress and childhood wheeze/asthma, examining effect modification by postnatal neighborhood-level opportunity as a potential buffer of stress. METHODS: Participants included 2056 mother-child dyads from ECHO PATHWAYS, a consortium of three prospective pregnancy cohorts (CANDLE, TIDES, GAPPS) from six U.S. cities. The number of maternal stressful life events (SLEs) experienced during pregnancy was reported retrospectively using the 14-item Pregnancy Risk Assessment Monitoring System SLE questionnaire (including traumatic, financial, emotional and relationship stressors). Parents reported child wheeze/asthma outcomes at age 4-6 (mean: 4.7 +/-0.7) years using a validated questionnaire: ever asthma, current wheeze (previous 12 months), current asthma (any two: ever asthma, current wheeze, or asthma-specific medication use), and strict asthma (ever asthma and either current wheeze or asthma-specific medications). We used modified Poisson regression to estimate risk ratios and 95% confidence intervals (95%CI), adjusting for confounders. We examined effect modification between SLEs and postnatal Child Opportunity Index (COI), a measure of neighborhood-level resources and conditions based on residence up to age 4, using interaction terms. RESULTS: Median of maternally-reported SLEs was 1 event (interquartile range: 0-2). Per one-unit increase in SLE, adjusted risk ratios (95%CI) were 1.06 (0.99, 1.13) for ever asthma (prevalence: 11%); 1.09 (1.03, 1.14) for current wheeze (prevalence: 15%); 1.05 (0.98, 1.12) for current asthma (prevalence: 12%); and 1.05 (0.98, 1.13) for strict asthma (prevalence: 9%). We found no evidence of effect modification by COI (all p-interaction >0.20). CONCLUSIONS: Childhood wheeze/asthma risk, particularly current wheeze, increases with increasing stress events experienced by women prenatally. In this study of women with few SLEs, these associations were not mitigated by postnatal neighborhood opportunity. KEYWORDS: Maternal Stress; Asthma; Wheeze; Neighborhood