Preinduction cervical ripening with prostaglandin E2 intracervical gel. Outpatient cervical ripening with nitric oxide donor isosorbide mononitrate prior to induction of labor. Outpatient cervical ripening with prostaglandin E2 gel in uncomplicated postdate pregnancies. The "PRIM" study: a randomized comparison of prostaglandin E2 gel with the nitric oxide donor isosorbide mononitrate for cervical ripening before the induction of labor at term. A comparison of prostaglandin E2 gel and prostaglandin F2 alpha gel for preinduction cervical ripening. Prostaglandin E2 cervical ripening without subsequent induction of labor. Intravaginal misoprostol as a cervical ripening agent. Preinduction cervical ripening with prostaglandin E2 (Prepidil) gel. Cervical ripening with intravaginal prostaglandin E2 gel.
A double-blind, placebo-controlled, dose-ranging study was undertaken to evaluate the efficacy of two doses of intracervical prostaglandin E2 gel in patients with unfavorable Bishop scores. Mean change in Bishop score, success of softening, time to labor, and time to delivery were all significantly different in the two treatment groups as compared with the placebo group. Twenty-three of 30 treated patients had uterine contractions lasting greater than four hours and eight patients delivered during the observation period. Moreover, one case of uterine hyperactivity and five cases of severe fetal heart rate decelerations were noted in the treatment groups. Although efficacious for cervical ripening, caution is warranted when using this technique in patients at risk for placental insufficiency. To examine the effectiveness and safety of outpatient vaginal administration of isosorbide mononitrate (IMN) to induce cervical ripening.
                A prospective, double-blind, placebo-controlled, randomized clinical trial was conducted on 102 singleton term pregnant women with unfavorable cervices who were randomly assigned to receive outpatient intravaginal IMN or placebo before admission for induction of labor. The main outcome variable was time from hospital admission to delivery. Secondary outcomes included fetal and maternal morbidity, labor characteristics, and incidence of cesarean delivery.
                The admission-delivery interval was 13.45+/-6.63 and 20.12+/-8.19 h (P=0.0001) for the IMN and placebo groups, respectively. Of the IMN patients 62.75% needed prostaglandins for cervical ripening versus 90.2% with placebo (P=0.002). The incidence of tachysystole was significantly lower in the IMN group (P<0.05) but there were no significant differences in cesarean delivery rate, neonatal outcomes, and incidence of hyperstimulation.
                Outpatient use of IMN resulted in shorter admission to delivery interval, and was associated with less prostaglandin use and lower incidence of uterine tachysystole. A double-blind, placebo-controlled, prospective investigation was undertaken to determine whether the outpatient administration of prostaglandin E2 gel was helpful for ripening the cervix in postdate pregnancies. One hundred eighteen women with an uncomplicated pregnancy at or beyond 42 weeks' gestation with an unripe cervix (Bishop score less than or equal to 5) were randomly administered a single dose of gel containing either 2.5 mg prostaglandin E2 (n = 55) or a placebo (n = 63) before induction of labor with Pitocin. No side effects were detected in these healthy mothers and fetuses. A distinct change in Bishop score after 12 hours occurred more often in the prostaglandin E2 than in the placebo group (42% versus 6%, p less than 0.0001). Forty-four women (80%) who had received prostaglandin E2 were admitted in early labor; they required little or no oxytocin for augmentation. The duration of labor and maximum dose of oxytocin infused were significantly decreased in the prostaglandin E2 group, and forceps delivery or primary cesarean sections were performed less often when prostaglandin E2 was used (24% versus 44%, p less than 0.05). The outpatient administration of a single dose of prostaglandin E2 gel is safe in the uncomplicated postdate pregnancy and was found to significantly change the unripe cervix, enhance the onset of labor, minimize the need for oxytocin administration, and encourage a spontaneous vaginal delivery. The purpose of this study was to compare the efficacy and safety profile of prostaglandin E2 with isosorbide mononitrate for cervical ripening before the induction of labor at term.
                Primigravid women were assigned randomly to receive either 40 mg of isosorbide mononitrate or 2 mg of prostaglandin E2. Efficacy outcomes were the cervical ripening effect of each agent and the time from treatment initiation to delivery. Safety outcomes were the incidence and frequency of maternal side effects and events that would be potentially hazardous for mother and baby during outpatient cervical ripening.
                Prostaglandin E2 was more effective than isosorbide mononitrate in inducing a change in modified Bishop score. Mean duration from treatment initiation to delivery was greater for isosorbide mononitrate than prostaglandin E2. There were no adverse events in the isosorbide mononitrate group that would contraindicate outpatient treatment. However, in the prostaglandin E2 group, 7% of the pregnancies had abnormal fetal heart rate patterns (P = .0002). Maternal satisfaction was significantly higher in the isosorbide mononitrate group.
                Although isosorbide mononitrate was less effective, maternal satisfaction was significantly greater. The safety profile of each agent was such that it would be reasonable to give isosorbide mononitrate, but not prostaglandin E2, on an outpatient basis. The unfavorable cervix remains a major obstacle to the successful induction of labor. Reported are results from an ongoing study of topical prostaglandin preparations used to effect preinduction cervical ripening. The current study compares the efficacy of 40 mg of prostaglandin (PG) F2 alpha versus 5 mg of PGE2, applied to the cervix in a methyltylose gel the night before attempted induction of labor. A prospective double-blind protocol was used similar to that which previously established the efficacy of the 5 mg of PGE2 preparation versus placebo at this institution. Results indicate the superiority of the PGE2 preparation as measured by change in Bishop score, Pitocin requirement, rate of cervical dilatation, and percentage of failed inductions. Cesarean section rates were similar in the two study groups, and no fetal or maternal morbidity was attributable to the preinduction ripening technique. To determine whether outpatient administration of intracervical prostaglandin (PG) E2 gel decreases the interval to delivery and duration of labor.
                A randomized, double-blind, placebo-controlled trial compared the intracervical placement of 0.5 mg PGE2 gel with placebo in 61 pregnant women at 38 weeks' or greater gestation with Bishop scores less than 9. Transvaginal cervical length, fetal fibronectin, and Bishop score were assessed before gel placement. Subjects were then allowed to go into spontaneous labor unless an indication for induction developed.
                Thirty women were assigned to PGE2 and 31 to placebo. There were no significant demographic differences between the groups and there were no differences in cervical length, fetal fibronectin status, or Bishop scores. Fifteen women in the PGE2 group and five in the placebo group went into labor and delivered within the first 2 days after gel placement (P = .007). The median interval to delivery was significantly shorter in the PGE2 group, at 2.5 days, compared with placebo, at 7 days (P = .02). Nulliparas in the PGE2 group had a median interval to delivery of 2 days, compared with 7 days for nulliparas receiving placebo (P = .03). Active phases of labor were significantly shorter in the PGE2 group and for women with a negative fetal fibronectin test who received PGE2.
                Outpatient administration of intracervical PGE2 gel shortened intervals to delivery and shortened labor. To determine if misoprostol (exogenous prostaglandin E1 PGE1) used vaginally was of value in improving the Bishop score, leading to an early safe vaginal delivery in women in whom the cervix is unripe and delivery is indicated.
                A double-blind clinical trial.
                Antenatal and labour wards of the University Hospital of the West Indies, Jamaica.
                Forty-five women in the third trimester with various obstetric indications for induction of labour and with no contra-indications to prostaglandins.
                The women were randomly assigned to receive treatment or a placebo. The treated group had 100 micrograms misoprostol inserted vaginally while the placebo was similarly inserted.
                Efficacy of the misoprostol was measured by the increase in the Bishop score 12 h after giving the treatment, the time between insertion and delivery, the need for oxytocin, and the outcome of the pregnancy.
                The prostaglandin was superior to the placebo in ripening the cervix and inducing labour. The change in Bishop score was 5.3 in the misoprostol group compared with 1.5 in the placebo group (P < 0.001). The mean time from insertion to delivery was 15.6 h in the former while it was 43.2 h in the placebo group (P < or = 0.001). The need for oxytocin was also significantly less in the women receiving the prostaglandin compared with those who received the placebo (29% vs 62%, P < 0.02). There was no difference in the two groups in the delivery outcome in terms of complications, Apgar scores and mode of delivery.
                Intravaginal misoprostol is an effective and cheap method of inducing labour in the third trimester. The effect of preinduction cervical ripening with Prepidil, a commercially prepared prostaglandin E2 gel (0.5 mg), on the outcome of induction of labor with intravenous oxytocin was investigated. Fifty-nine pregnant women were randomized either to receive intracervical application of the gel or to undergo sham application. Compared to control subjects, patients in the group given Prepidil had significant increases in cervical Bishop scores, shorter induction-to-delivery intervals, lower maximum doses of oxytocin, and fewer days of induction. Systemic side effects were minimal, but 37% (11 of 30) of the gel-treated patients experienced labor prior to receiving oxytocin and 20% (six of 30) were actually delivered during the 12-hour ripening period. No differences in route of delivery or fetal outcome were found between the two groups. Fifty-four patients were randomized in a double blind fashion into either a placebo group or a group treated with a 3 mg dose of an intravaginal prostaglandin E2 gel. The group receiving the prostaglandin E2 gel had a mean change in cervical score of 2.7 while the patients in the placebo group had no significant change. Even though a significantly higher number of patients in the prostaglandin group went into spontaneous labor, the incidence of cesarean section was not different between the two groups. Upon comparing the conflicting reports of various studies on the subject, it is concluded that the method of product preparation, particularly the source of prostaglandin E2 utilized and the choice of drug vehicle, may be important variables in determining treatment success, as measured in terms of decreased cesarean section rate.
NO donors are superior to placebo or no treatment, but inferior to prostaglandins for first-trimester cervical ripening, and associated with more side effects.