Exposure to phthalate metabolites, phenols and organophosphate pesticide metabolites and blood pressure during pregnancy

Introduction: Hypertensive disorders during pregnancy are one of the leading causes of maternal and offspring mortality and morbidity. Exposure to environmental chemicals is suspected to increase blood pressure (BP) but few studies have investigated the impact of non-persistent chemicals, in particular among pregnant women.

Methods: Women included in the study were 152 volunteer participants in the Human Early-Life Exposome (HELIX) project. They provided 3 urine samples daily over one week in two pregnancy trimesters (at around 18 and 32 weeks of gestation) to assess their exposure to phthalates (10 metabolites), phenols (7 compounds) and organophosphate pesticides (4 metabolites). BP was measured at the end of the two collection weeks. Associations between biomarkers of exposure and BP were investigated using generalized estimating equations (GEE) and linear regression, and adjusted for potential confounders.

Results: A significant decrease in systolic and/or diastolic BP was observed with exposure to some phthalate metabolites, BPA, and parabens (e.g. β GEE models for systolic BP = -0.91 mmHg (95%CI: -1.65; -0.17) per doubling of BPA concentrations). These associations were more frequently observed in the second trimester of pregnancy and remained statistically significant after correction for multiple testing for BPA only. No associations were observed with organophosphate pesticides.

Conclusion: This study investigates the effect of exposure to non-persistent chemicals assessed using multiple biospecimens per subject on BP during pregnancy and suggests that higher exposure to some phthalates and phenols but not pesticides is associated with lower BP during pregnancy.