Abstract P264: Metal Exposures and Preeclampsia in the Boston Birth Cohort

Introduction: Preeclampsia is a leading cause of maternal and perinatal morbidity and mortality, accounting for 50,000-60,000 deaths per year worldwide. Animal studies have linked metal exposures to its development but epidemiologic studies have had inconsistent findings. We assessed the associations between metal exposures and preeclampsia in a prospective cohort. Methods: A total of 1,346 women from the Boston Birth Cohort (enrolled from 1998 to 2018) had complete data on the exposures and outcome and were free of both chronic and gestational hypertension. Metal exposures, including manganese (Mn), cadmium (Cd), lead (Pb), mercury (Hg), and selenium (Se) were measured from red blood cells (RBCs) collected within 1 to 3 days after delivery. Preeclampsia (including HELLP syndrome) diagnosis was ascertained from medical records. Logistic regression models were fitted for each metal. Covariates adjusted for included age at delivery, race, pre-pregnancy body mass index, education, parity, and smoking status during pregnancy. Results: A total of 119 (8.84%) women developed preeclampsia. A 1 standard deviation (SD) (15.42 μg/L) increase in RBC Mn was associated with a 0.71 (95% confidence interval (CI): 0.56, 0.90) times lower odds of preeclampsia. Compared to the 1 st quintile of RBC Mn, the 5 th quintile was associated with 0.39 (95% CI: 0.20, 0.76) times lower odds of preeclampsia. In contrast, a 1 SD (0.68 μg/L) increase in RBC Cd was associated with a 1.17 (95% CI: 0.94, 1.46) times higher odds of preeclampsia, and the odds for the 5 th quintile of RBC Cd was 2.04 (95% CI: 1.03, 4.04) times higher than the 1 st quintile (Figure) . Null associations were observed for RBC Pb, Hg and Se. Conclusion: RBC Mn was associated with lower odds of preeclampsia, while Cd was associated with higher odds. Findings from this study help elucidate potentially modifiable causes of preeclampsia and inform interventions to reduce the burden of this important pregnancy complication.