Urinary cadmium levels during pregnancy and postpartum. A longitudinal study.

It is well established that pregnancy induces physiological, metabolical and hormonal changes. As a consequence, trace metal metabolism can be affected. The aim of the present study was to assess the urinary cadmium levels in women during gestation and postpartum. The survey was conducted in a group of nonoccupationally cadmium-exposed women from Southern Catalonia (NE, Spain). Urine samples were obtained before pregnancy, during the 6th, 10th, 26th, and 30th wk of gestation, as well as during the 5th and 24th wk after delivery. Urinary cadmium levels were determined by graphite furnace atomic absorption spectrophotometry. The concentrations of zinc and copper in plasma were also measured. Moreover, to assess the effect of the diet during pregnancy, dietary ingestions of zinc, iron, and calcium were also determined. A significant decrease of plasma zinc levels could be observed during the last two trimesters of pregnancy, while plasma copper concentrations significantly increased during the same period. Urinary cadmium concentrations ranged from 0.05 to 3.79 micrograms/g creatinine (geometric mean 0.49 +/- 2.26 micrograms/g creatinine). No significant changes in urinary cadmium concentrations during pregnancy and postpartum could be observed.