Association of thallium exposure during pregnancy with maternal blood pressure and hypertensive disorder complicating pregnancy

Objective: To investigate the association of thallium exposure during pregnancy with pregnant blood pressure changing and hypertensive disorder complicating pregnancy(HDCP). Methods: A total of 3 240 pregnant women who had establish maternal health care manual in Ma'anshan Maternal and Child Health-Care Hospital and met the inclusion and exclusion criteria were included in this study between May 2013 and September 2014.We collected their general demographic characteristics and blood pressure through questionnaire and medical records. Meanwhile we measured serum thallium concentrations by experimental technology. We use multiple logistic regression to analyze the association between thallium exposure during pregnancy and HDCP. Mixed linear model were used to analyze the association between thallium concentration and maternal systolic blood pressure (SBP) or diastolic blood pressure(DBP) in different trimesters Results: The age of 3 240 pregnant woman was (26.61±3.64) years, and the detection rate of HDCP was 5.9%(191).The median (P25, P75) of thallium concentrations in first trimester, second trimester and third trimester were 62.96 (50.79, 77.04), 62.19 (50.87, 75.26), 48.84 (38.00, 66.00) ng/L, respectively. Multiple logistic regression results suggested after adjusting various confounding factors, the risk of HDCP in pregnant women with high concentrations of thallium (>77.04 ng/L) in the first trimester is 1.75 (95%CI:1.01-3.03) times higher than which with low concentrations(<50.82 ng/L). Mixed linear model results suggested there are positive correlation between thallium concentrations with maternal DBP in first trimester (β=1.12, 95%CI: 0.39-1.85). Conclusion: Exposure to high levels of thallium during first trimester may increase the risk of HDCP, and the exposure of thallium may be effective to DBP of pregnant.