Vitamin supplements may increase risk of PROM

Risk of premature rupture of the membranes (PROM) and preterm PROM (PPROM) unexpectedly increased with vitamin C and E supplementation, according to a report in the October issue of the American Journal of Obstetrics and Gynecology.

Joseph A. Spinnato II, MD, of the University of Cincinnati College of Medicine, and colleagues report on a planned secondary analysis of a placebo-controlled, double-blind trial examining antioxidant supplementation during pregnancy. The report focuses on the incidence of PROM and PPROM in women receiving either 1,000 mg of vitamin C and 400 IU of vitamin E daily, or placebo.

Overall, PROM (10.6%) and PPROM (4.6%) were more common with antioxidant supplementation than with placebo (5.5% and 1.7%, respectively), the researchers report. Adjusted risk ratios indicated pregnant patients receiving antioxidant supplementation were 1.89 times more likely to develop PROM and 2.68 times more likely to develop PPROM than those taking placebo, the report indicates.

Spinnato JA 2nd, Freire S, Pinto e Silva JL, et al. Antioxidant supplementation and premature rupture of the membranes: a planned secondary analysis. Am J Obstet Gynecol. 2008;199:433.e1-.e8.