Prospective Association Between Manganese in Early Pregnancy and the Risk of Preeclampsia.

BACKGROUND: Manganese, an essential micronutrient, has been found in lower concentrations among women with preeclampsia in cross-sectional and case-control studies without establishment of a temporal relationship. METHODS: We evaluated the prospective association of manganese (in red blood cells) in first trimester of pregnancy with incidence of preeclampsia (ascertained by reviewing medical records) among 1,312 women in eastern Massachusetts (Project Viva, 1999-2002). We used log-binomial regression to examine the manganese-preeclampsia relationship, adjusting for maternal age, race/ethnicity, parity, prepregnancy body mass index, blood pressure, and hematocrit. RESULTS: The median (25th, 75th percentile) manganese concentrationin red blood cells was 16.2 ng/g (13.1, 20.4) and 48 (4%) women developed preeclampsia. We observed an inverse dose-response relationship between manganese and preeclampsia. Compared with women in the lowest tertile, women in the middle manganese tertile had 0.81 times the risk of preeclampsia (95% CI: 0.43, 1.5) and those in the highest tertile had 0.50 (95% CI: 0.25, 0.99) times the risk. CONCLUSIONS: Our results provide insight into a potentially modifiable way to prevent preeclampsia.