The relationship between cadmium and lead with selenium, copper and zinc in normal and intrauterine growth restriction pregnancy

Abstract

Elemental status of the mother and newborn has been connected to pregnancy outcome and this study investigated placental Pb, Cd, Se, Cu and Zn concentrations in a group of pregnancies with birth weight appropriate for gestational age and in a group of intrauterine growth restriction cases. Collection of placenta samples was performed during 2003 and 2004 from non-smoking women (n = 85) who volunteered to take part in the study. Intrauterine growth restriction was defined as birth weight below the 10th percentile at gestational age. Following wet digestion, Se was determined using HG-AAS instrument, Cd, Pb by GFAAS and other elements were measured by FAAS. Cadmium and lead content (medians and ranges) in the ‘ normal’ group were 8.03 (2.10-19.20), 45.23 (15.54-93.48) ppb and in the IUGR group 9.11(2.63– 27.00), 52.38 (16.02– 112.06) ppb, respectively. Cadmium level was significantly higher in the IUGR group. Concentrations of Se, Cu and Zn were 0.15 (0.10-0.24), 1.14 (0.78– 2.01), 10.59 (6.38– 16.64) ppb in the ‘ normal’ group and 0.14 (0.10-0.24), 1.21 (0.76– 2.14), 10.94 (7.30– 15.51) ppb in the IUGR group. Significant difference between the pregnancy outcome groups was determined for Se. Significant partial correlations between placental levels of toxic and essential elements were only evident in the IUGR group: Pb and Se (r=0.40, p<0.01), Cd and Cu (r=0.36, p<0.05), and Cd and Zn (r=0.30, p<0.05). This could be indicative of a protective interaction which might have adversely influenced pregnancy outcome (newborn weight) due to depletion of available forms of microelements.