Experiences of multiple psychosocial stressors and associations with oxidative stress biomarkers during pregnancy.

BACKGROUND

Oxidative stress is hypothesized to be one mechanism linking psychosocial stressor exposure to preterm birth and other adverse pregnancy outcomes. However, prior studies have focused solely on singular psychosocial stressors, which may not reflect real world exposures as pregnant women may experience multiple stressors simultaneously.

METHODS

Participants included a subset of the Chemicals in Our Bodies cohort, a prospective birth cohort in San Francisco, California (N = 227). Self -reported psychosocial stressors were assessed via questionnaires administered during the second trimester that addressed financial strain, food insecurity, job strain, neighborhood quality, caregiving, stressful life events, unplanned pregnancy, and perceived community status. Oxidative stress biomarkers were measured during the second trimester of pregnancy and included 15-F2t-IsoP, and its two major metabolites 2,3-dinor-5,6-dihydro-15-F2t-IsoP, and 2,3-dinor-15-F2t-IsoP, and PGF2α. Linear regression models were used to examine associations between individual and pairwise combinations of psychosocial stressors in relation to each oxidative stress biomarker.

RESULTS

15-F2t-IsoP, 2,3-dinor-15-F2t-IsoP, and 2,3-dinor-5,6-dihydro-15-F2t-IsoP were elevated among participants reporting experiences of low perceived community status, job strain, poor neighborhood quality, food insecurity, and stressful life events (e.g., β = 0.36, 95 % CI = 0.00, 0.72 for food insecurity in association with 15-F2t-IsoP). In models that included pairwise combinations of stressor exposures, nearly every combination was also associated with an increase in all oxidative stress biomarkers compared to those who experienced one or neither stressor. For example, stressful life events and poor neighborhood quality was associated with statistically significant increases in all biomarkers (e.g., β = 0.94, 95 % CI = 0.17, 1.71 for 2,3-dinor-5,6-dihydro-15-F2t-IsoP).

CONCLUSIONS

Urinary oxidative stress biomarkers were elevated among pregnant women exposed to psychosocial stressors, and exposure to multiple stressors resulted in the strongest associations. These findings support oxidative stress as one potential biological pathway linking prenatal psychosocial stress to preterm birth and other adverse pregnancy outcomes.