A comparative randomized study on effect of vaginally administered glyceryl trinitrate placebo on cervical ripening prior to induction of labor in overdue pregnancies

OBJECTIVE: The aim of this study is to examine the effectiveness and adverse effects of local glyceryl trinitrate (GTN) application during labor compared with a placebo group. METHODS: The study consisted of 70 pregnant women with overdue pregnancies who presented to the hospital for labor induction between January 2009 and January 2011 in the Obstetrics Clinic of Istanbul Süleymaniye Gynecology and Obstetrics Education and Training Hospital. Vaginal suppositories-containing GTN (36/70) or placebo (34/70) was administered to the participants in a randomized fashion. The placebo and GTN involving vaginal ovules used in the study were prepared in the Pharmacy Department of Istanbul University Faculty of Pharmacy. Maternal effects during labor, rates of normal vaginal and C/S deliveries, the interval between the initial medication and delivery, and amount of total oxytocin used were compared between the GTN and placebo groups. RESULTS: There were no significant differences between the GTN and placebo groups regarding bishop scores, the interval between medication and delivery, delivery types, indications for cesarean section, and complications including hyperstimulation, tachysystole, uterine rupture, placental abruption, and uterine atony (P > 0.05). CONCLUSION: Our results revealed that there were no differences between GTN and placebo regarding their effect on cervical ripening in overdue pregnant women.