Association Between Fluoride Exposure and Immune System Biomarkers in Pregnancy

Abstract

Objective: The present study investigated whether fluoride exposure is associated with maternal immune system function in a Canadian pregnancy cohort. Methods: Urinary fluoride concentrations were measured in each trimester, dilution-adjusted, and averaged across pregnancy. Drinking water fluoride concentrations (WFC) were collected from water treatment plants. Maternal immune system biomarkers included interleukin (IL)-6, IL-8, tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and C- reactive protein (CRP) from plasma samples collected during the third trimester of pregnancy. Results: We observed a departure from linearity in the association between WFC and CRP, such that CRP levels increased with increasing WFC at levels below 0.63 mg/L. Urinary fluoride concentrations were not associated with maternal immune system biomarkers. Conclusion: Water fluoride concentrations were associated with changes in some maternal immune system biomarkers, suggesting fluoride may be implicated in inflammatory processes during the third trimester. Further characterization of the timing of maternal immune activation is needed to advance our understanding of critical vulnerability periods during pregnancy.