Korean J Obstet Gynecol.  2001 Jul;44(7):1275-1280.

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

• Kim YH
• Cho JS
• Lee CH
• Park YW

Abstract

OBJECTIVE
This study is directed to determine whether the concentrations of nitrate and nitrite, metabolites of nitric oxide, in vaginal secretions could be used to predict a premature delivery. METHOD: A total of 60 pregnant women from March, 2000 to February, 2001 received continuous prenatal care and underwent delivery in our hospital was enrolled in the study. Gestational age was ranged between 20 and 37 weeks. Those patients were divided into four groups according to clinical parameters such as preterm labor, premature rupture of membranes and premature delivery. Specimens were obtained by thorough washing of vagina with 5 mL sterile physiologic sodium chloride solution for determination of nitric oxide metabolites. The total nitrate and nitrite concentration was determined by treatment with nitrate reductase followed by the Griess reaction.
RESULTS
Subjects were divide into four groups (group I, no preterm labor and term delivery[n=19]; group II, preterm labor and term delivery[n=12]; group III, preterm labor and consequent premature delivery[n=6]; Group IV, preterm labor with premature rupture of membranes and consequent premature delivery[n=23]). Total nitrate and nitrite concentrations in group II-IV (62.2+/-50.3micromol/L in group II, 113.3+/-77.0micromol/L in group III, 101.9+/-72.4micromol/L in group IV) were significantly higher than the concentration in Group I (9.4+/-11.9micromol/L). From the receiver operating characteristic curve in the prediction of premature delivery, we set 27.6micromol/L as a cut-off value in this study. Sensitivity, specificity, positive predictive value, and negative predictive value were 71.9%, 78.6%, 79.3%, and 71.0%, respectively.
CONCLUSION
Patients with premature delivery do have increased nitric oxide metabolites in vaginal secretions. These results suggest that nitric oxide may be involved in the initiation of cervical ripening and used as a predictor of premature delivery.

Keyword

Nitric oxide; Nitrate; Nitrite; Premature delivery

MeSH Terms

Cervical Ripening
Female
Gestational Age
Humans
Membranes
Nitrate Reductase
Nitric Oxide
Obstetric Labor, Premature
Pregnancy
Pregnant Women
Prenatal Care
ROC Curve
Rupture
Sensitivity and Specificity
Sodium Chloride
Vagina
Nitrate Reductase
Nitric Oxide
Sodium Chloride