Associations between metal mixture exposure and emotional distress symptoms among pregnant women: A prospective study.

BACKGROUND

Emotional distress during pregnancy, including anxiety and depression, represents a critical public health issue with detrimental effects on maternal health and offspring outcomes. Exposure to metal mixtures is common in real life, which could cause emotional distress. However, studies on metal exposures and emotional distress during pregnancy remain limited, with inconsistent findings and key metals understudied.

METHODS

This prospective study aimed to examine whether urinary metals including lead (Pb), cadmium (Cd), arsenic (As), copper (Cu), manganese (Mn), vanadium (V), molybdenum (Mo), and uranium (U) in the first trimester is individually and jointly associated with women's emotional distress in the first and third trimesters. 217 pregnant women during the first trimester were recruited from Jinan, China, and 168 of them were followed up in the third trimester. The seven-item Generalized Anxiety Disorder Scale (GAD-7) and nine-item Patient Health Questionnaire (PHQ-9) were used to assess anxiety and depression symptoms, respectively.

RESULTS

The generalized additive models (GAM), Bayesian kernel machine regression (BKMR), and Quantile g-computation (Q-gcomp) models consistently showed an inverse correlation between As exposure and PHQ-9 scores during early pregnancy, while both the Q-gcomp and BKMR models revealed a positive correlation between U exposure and PHQ-9 scores in the third trimester. BKMR analysis also identified As-U and As-V interactive effects on depression symptoms in the third trimester, as well as Cd-U and Mn-U interactive effects on anxiety symptoms in the third trimester. Moreover, generalized linear mixed model (GLMM) showed urinary As was negatively associated with PHQ-9 scores throughout pregnancy.

CONCLUSION

These findings indicate that exposure to As and U as part of a mixture are key metals associated with pregnant women's depression symptoms. Future research is needed to confirm our results and clarify the underlying mechanisms.