Maternal and umbilical cord blood levels of mercury, manganese, iron, and copper in southern Taiwan: A cross-sectional study

Background The effect of maternal exposure to essential minerals and heavy metals on fetus is an important issue, which affects women around the world. Few data are available on the concentration of both essential minerals and heavy metals in maternal/fetal medicine. The aims of this study were to (1) assess the correlation of mercury (Hg), manganese (Mn), iron (Fe), and copper (Cu) in paired maternal/fetal blood samples, and (2) study potential confounding factors during pregnancy. Methods Our study recruited 145 healthy pregnant women with a mean age of 28.06 years, gathering information by collecting interviewer-administered questionnaires. Paired maternal/fetal blood samples were collected by delivery. Results There was a positive correlation of Hg (r = 0.78, p < 0.001), Mn (r = 0.31, p < 0.001), Fe (r = 0.17, p = 0.038), and Cu (r = 0.21, p = 0.010) in paired maternal/fetal samples. Prenatal vitamin use (>3 times/wk) was significantly associated with lower maternal Hg (adjusted odds ratio 0.272, p = 0.005) and lower maternal Cu (adjusted odds ratio 0.267, p = 0.004) levels. Median fetal Hg, Mn, and Fe levels were higher than corresponding maternal levels, while median fetal Cu level was lower than maternal Cu level. Conclusion There was a positive correlation of Hg, Fe, Cu, and Mn in paired maternal/fetal samples in this series. Our findings have raised the possibility of reducing maternal Hg and Cu by way of prenatal vitamin supplementation.