The intrapartum content of toxic metals in maternal blood and umbilical cord blood.

The concentrations of cadmium, lead and total mercury were determined by atomic absorption spectrometry in maternal blood and umbilical cord blood collected during the III-rd stage of term delivery from 56 mother-neonate pairs. Cadmium and mercury levels measured on both sides of placenta did not differ significantly while lead levels in maternal blood were significantly higher than its cord blood values. In all three metals studied, the concentrations in maternal blood strongly correlated with the corresponding cord blood values. A significant, positive correlation was established between the parity of the examined women and the umbilical cord blood contents of lead and mercury. The obtained results support the opinion that human placenta does not form an effective barrier to toxic metal intake by the fetus.