Hydrogen peroxide-producing Lactobacilli in the vaginal flora of pregnant women with preterm labor with intact membranes

Objectives: To investigate the role of vaginal infection in preterm delivery, we studied characteristics of vaginal discharge related to hydrogen peroxide-producing Lactobacilli. Methods: Vaginal specimens were obtained from 66 women with normal pregnancy and 30 women with preterm labor with intact membranes. pH, leukocyte counts on wet smear, and scores by Nugent criteria on Gram stain were measured. Lactobacilli were tested for their production of hydrogen peroxide. Results: Leukocyte levels in wet smears and Nugent scores of Gram-stained smear of women with preterm labor with intact membranes were significantly higher than those of normal pregnant women (P < 0.01, P < 0.05). Hydrogen peroxide-producing Lactobacilli levels in the vaginal flora of women with preterm labor with intact membranes were significantly lower (P < 0.01). Conclusion: Distribution of hydrogen peroxide-producing Lactobacilli in vaginal flora as defense factors for infection may have an important role in the pathophysiology of preterm labor.