Cadmium concentrations in blood and urine of pregnant women at delivery and their offspring.

The levels of cadmium in blood (CdB) and in urine (CdU) were measured in 40 women at delivery and in their offspring. The women were not occupationally exposed to cadmium. The CdB levels in the pregnant women were significantly lower than in a control group consisting of 40 subjects of the same sex and age living in the same area. The difference can probably be ascribed to the physiological hemodilution that takes place in pregnancy. The CdU levels in the two groups were identical, which suggests that no mobilization of the metal from tissue deposits occurs during pregnancy. The presence of cadmium in the blood and urine of the newborn demonstrates that cadmium crosses the placental barrier. There was a rather high correlation between the CdU levels of mothers and offspring. Since only traces of cadmium are present in tissues at birth, it is speculated that the CdU levels in the newborn are influenced by the tissue deposits of cadmium in the mother. Further research is required to ascertain whether, in the case of women occupationally exposed to cadmium or living in cadmium polluted areas, transfer of the metal across the placenta can produce toxic effects in the foetus.