RESUMO
OBJECTIVE: To determine whether vitamins C and E supplementation lowers oxidative stress marker levels and improves pregnancy rate in women with endometriosis. METHODS: Thirty-four women with endometriosis received a bar containing vitamins C and E (343 mg and 84 mg, respectively) or placebo for 6 months. Plasma and peritoneal fluid levels of malondialdehyde (MDA) and lipid hydroperoxides (LOOHs) were measured for all women and compared between the 2 groups. Data were analyzed by the t test or 1-way analysis of variance for parametric data and the Mann-Whitney rank sum test or Kruskall-Wallis test for nonparametric data. The Fisher exact test was used to compare pregnancy rates. RESULTS: After 4 months, the study group had lower levels of MDA and LOOHs than the control group, and the difference became statistically significant in the fourth month for MDA levels and in the sixth month for LOOH levels. The postintervention pregnancy rates were 19% and 12% in the supplementation and placebo groups, respectively, but the difference was not significant. CONCLUSIONS: Vitamins C and E supplementation was associated with a decrease in the concentration of oxidative stress markers in women with endometriosis. The pregnancy rate, however, did not improve during or after the intervention.