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

Objective: To examine the correlation of zinc and copper serum concentration level, body mass index, age and parity with premature rupture of the membranes. Methods: 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 5mL 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. Results: 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. Conclusion: Zinc and copper concentration levels in maternal serum had no effect on premature rupture of the membranes. (author)