Smoking during pregnancy and the perinatal cadmium burden.

The association between maternal smoking and both morphometric birth parameters and the perinatal cadmium burden were studied. The cadmium concentrations were measured by atomic absorption spectrometry in 100 samples of maternal whole blood (MB) and in 93 samples of umbilical cord blood (CB). In the group of nonsmokers, significantly higher birth weight and decreased relative placental weight were noted as compared to the group of smokers who smoked more than 6 cigarettes a day (p less than 0.05). In both maternal and cord blood samples, the measured Cd levels were found to be significantly higher in smokers than in the nonsmoking subjects (for MB and CB p less than 0.01 and p less than 0.01 respectively). The average number of cigarettes smoked daily by the women had little effect on the levels of the metal. The Cd-MB strongly correlated with the Cd-CB (p less than 0.001). The cadmium values determined in MB and CB did not significantly affect any of the studied fetoplacental parameters. The reported findings give support for placental permeability to cadmium in humans and confirm that smoking during pregnancy leads to elevated Cd concentrations in both the mother and the fetus.