Maternal and cord serum calcium, copper, iron and zinc concentrations were analyzed in 20 women with a postdate pregnancy. The control group consisted of 20 parturients with delivery at term and their newborns. Serum free estriol (E3) was also determined. Maternal serum copper, zinc and E3 were statistically significantly lower, while cord serum copper and fetomaternal ratio of zinc were significantly higher in the study group than in the control group. Further, a positive correlation between E3 and maternal serum copper level (r = 0.63) was found.