Elevation of total nitrite and nitrate concentration in vaginal secretions as a predictor of premature delivery

We measured the total concentration of nitrite and nitrate, metabolites of nitric oxide, in vaginal secretions from pregnant women at 22 to 32 weeksʹ gestation. Total nitrite and nitrate concentrations in patients with preterm premature rupture of membranes and in those with preterm labor and subsequent premature delivery were significantly higher than concentrations in patients who were delivered at term. Elevated total nitrite and nitrate concentration may predict premature delivery.