Does vaginal pH affect the efficacy of dinoprostone in cervical ripening/labor duration?

BACKGROUND: Prostaglandins are effective in the ripening of the cervix and facilitating labor induction. Vaginal pH is probably an important factor in the effectiveness of vaginal prostaglandins. The aim of this study was to evaluate the effect of vaginal pH on the function of prostaglandin vaginal tablet during labor. METHODS: This is a double-blinded clinical trial study of 147 pregnant primigravid trated in the Yahyanejad Hospital of Babol (Iran) from January 2006 to December 2007. Initial pH was measured during vaginal examination with nitrazin paper and the Bishop score was determined. All women received vaginal dinoprostone inserted in the posterior fornix of the vagina for cervical ripening and the second dose was administered if the uterine contractions were inadequate. Reassessment of the Bishop score after 12 hours, duration of latent and active phases, and also the duration of the second stage of labor were compared between the two groups with low or high vaginal pH. RESULTS: The incidence of Cesarean section was lower in women with high vaginal pH but was not statistically significant. The Bishop score after 12 hours, latent phase, and second stage durations were not different in the two groups of high or low vaginal pH, but active phase duration in patients with high pH was significantly shorter than those with low pH (p = 0.019). CONCLUSION: High vaginal pH influences the function of prostaglandin tablet as a reduction in duration of the active phase of labor.

Effects of vaginal versus oral misoprostol to terminate second-trimester pregnancy.

OBJECTIVES: Using surgical methods compared to medical methods, such as misoprostol for termination of pregnancy, has several side effects. This study was performed in order to compare the effect of vaginal and oral misoprostol in second-trimester pregnancy termination (14-24 weeks). MATERIALS AND METHODS: The authors performed a clinical trial study in 40 pregnant women at 14 to 24 weeks of gestation and candidates for medical interruption of pregnancy. All patients received 600 microg of vaginal misoprostol as primary dosage and then, were placed randomly in two groups consisting of 20 patients that received 400 microg of vaginal or oral misoprostol, every four hours, up to three doses. If the abortion was incomplete, oxytocin was used. Twenty-four hours after the procedure, uterine sonography was performed in all patients and if residue was found, the patients were then candidates for curettage. RESULTS: Seventeen patients (85%) in the vaginal group and 17 patients (85%) in the oral group had successful pregnancy interruption. The mean interval until the discharge of pregnancy products in the vaginal group (15/42 +/- 10/84) showed no significant difference compared to the oral group (12/65 +/- 7/8) and no significant differences in side-effects were found between the two groups. CONCLUSION: Oral misoprostol is as effective as vaginal misoprostol in performing second-trimester abortion. It appears that the vaginal misoprostol primary dose together with the continuation of oral dose is not more effective compared to the vaginal misoprostol method alone.