INCREASED BLOOD LEAD AND DECREASED CALCIUM LEVELS DURING PREGNANCY - A PROSPECTIVE-STUDY OF SWEDISH WOMEN LIVING NEAR A SMELTER

Objectives. The purpose of this study was to monitor blood lead in a n orthern Swedish cohort of mothers and children during pregnancy and at birth. Methods. Blood lead was analyzed during pregnancy and in the u mbilical cords of 290 women living near a smelter and in 194 control s ubjects. Results. During pregnancy, there were statistically significa nt overall increases in blood lead concentrations by 20% and 15% in th e smelter and reference areas, respectively. Mean maternal blood lead concentrations at delivery were 0.15 mu mol/L (3.11 mu g/dL) in the sm elter area and 0.13 mu mol/L (2.69 mu g/dL) in the control area. Umbil ical cord blood lead levels were 80% to 87% of the maternal levels. Bl ood lead levels were influenced by place of residence, employment at t he smelter, smoking, and wine consumption. Maternal serum calcium leve ls decreased during pregnancy and were significantly lower than those of the newborns. Conclusions. An increase in blood lead concentrations was found during pregnancy, despite increased blood volume and unchan ged or decreasing environmental lead levels. The mobilization of lead from bone during pregnancy may explain the increase.