Maternal serum copper and zinc levels and premature rupture of the foetal membranes

To examine the correlation of zinc and copper serum concentration level, body mass index, age and parity with premature rupture of the membranes. The cross-sectional study was conducted between 2009 and 2010 at the fertility ward of Amiralmomenin Hospital of Semnan University of Medical Sciences, Iran. It comprised 100 full-term pregnant women with and without premature rupture of the membranes and 50 non-pregnant women as controls The diagnosis of rupture of membranes was made on the basis of gross leakage of fluid within the vagina and a positive nitrazin test. A sample of 5 mL blood was collected. The levels of zinc and copper were determined by an enzyme-linked immunosorbent assay method. Mean values among the three equal groups were compared using standard analysis of variance. Statistical significance was set at p < 0.05. Pregnant women with (p < 0.027) and without (p < 0.019) premature rupture of the membranes had significantly lower serum zinc concentration than non-pregnant women. Inversely, the maternal serum copper concentration level was higher in both groups of pregnant women than in the controls (p < 0.001). However, the results suggest that the decreased plasma zinc concentration and increased copper concentration in pregnant women were not the cause of premature rupture of the membranes at term. Zinc and copper concentration levels in maternal serum had no effect on premature rupture of the membranes.