[Comparison between prostaglandin E2 gel and oxytocin in medically indicated labor induction]. A randomized trial of vaginal prostaglandin E2 for induction of labor. Insert vs. tablet. A randomized trial of management of pre-labor rupture of membranes at term in multiparous women using vaginal prostaglandin gel. [Artificial induction of labor at term for medical reasons. Comparison of 2 technics for labor induction, oxytocin + early artificial rupture of the membranes versus prostaglandin E2 vaginal gel. Open randomized controlled study]. [Multicenter experiences with the intracervical administration of a new PGE2 gel in labor induction]. Induction of labour: a comparison of a single prostaglandin E2 vaginal tablet with amniotomy and intravenous oxytocin. Early labor initiation with oral PGE2 after premature rupture of the membranes at term. Cervical ripening and labor outcome with preinduction intracervical prostaglandin E2 (Prepidil) gel. Induction of labour: the effect of vaginal prostaglandin or i.v. oxytocin--a matter of time only?
The use of prostaglandins (PG) increasingly replaces the "classical" method of induction of labour by means of oxytocin and amniotomy, the last-named method being associated, especially in women with an unripe cervix, with side effects like prolonged labour and a higher rate of obstetric surgery. In this study the point of interest was whether prostaglandins offer any advantages over the classical method in respect of efficacy and maternal and foetal tolerance. 99 patients subdivided into primiparae and multiparae were randomly assigned to group A or B. In group A labour was induced with 1 mg resp. 2 mg PGE2 intravaginally at an interval of 6 hours. In group B the method of induction consisted of intravenous oxytocin and amniotomy. The success rate of induction was almost equal in both groups. However, in those patients where PGE2 induction did not succeed and who could not be delivered within 12 hours the cervical score was significantly improved in comparison to the oxytocin group. Based on the experience reported in the literature, one might speculate that an increased dosage could still improve the results of vaginally administered PGE2 gel. To compare the efficacy and safety of a prostaglandin E2 (PGE2) vaginal insert with PGE2 administered as a vaginal tablet.
                A randomized, observational study was performed. Women requiring induction of labor were randomly assigned to receive either a 10-mg PGE2 vaginal insert (group 1, n = 100) or 3-mg PGE2 tablets twice at six-hour intervals (group 2, n = 100). The primary efficacy outcome variable was vaginal delivery within 24 hours of insertion. The criteria for safety were the occurrence of uterine hyperstimulation, abnormal fetal heart rate patterns, use of beta 2-sympathomimetic drugs and fetal outcome.
                No differences in terms of vaginal delivery or cesarean section within 24 hours of induction were found. The cesarean section rate was 21% in group 1 and 22% in group 2. The interval from insertion of the induction agent to the onset of regular uterine contractions and the insertion-to-delivery interval were not different between the two cohorts. No difference in the frequency of uterine hyperstimulation, use of beta 2-sympathomimetic drugs, abnormal fetal heart rate patterns, fetal outcome, or oxytocin and analgesic requirements were found. In seven of eight patients in group 1 who experienced uterine hyperstimulation, removal of the insert was sufficient to stop it, whereas in group 2, of nine cases, eight needed medical interventions to end hyperstimulation (P = .003).
                The continuous release of PGE2 from the vaginal insert permits controlled induction of labor, and easy removal of the drug in cases of uterine hyperstimulation is possible. To compare conservative management of pre-labor spontaneous rupture of membranes (SROM) with the use of prostaglandin (PG) E2 in healthy parous women at term (gestational age at least 37 weeks).
                An open randomized study was conducted with 100 parous women; 50 were treated conservatively for 24 hours, and 50 were managed actively using PGE2 gel (1 mg), administered at admission and repeated 6 hours later if labor was not established. Both groups received intravenous oxytocin if labor did not start within 24 hours after admission.
                The use of PGE2 gel led to a significant reduction in the mean interval (+/- standard error of the mean) from SROM to onset of labor: 17.26 +/- 1.51 hours in the conservative group versus 6.50 +/- 1.23 in the PGE2 group. A significantly smaller proportion of subjects required oxytocin in the PGE2 group (12 versus 38%, P < .02). The two groups were comparable with respect to analgesic requirements. Within 24 hours of SROM, 80% of the women in the PG group and 56% in the conservative group had delivered (P < .02). Most women delivered vaginally, 96% of those managed conservatively and 100% of those managed actively with PGE2.
                Active management using PGE2 gel in parous women with pre-labor SROM significantly improves the time to delivery without influencing the cesarean rate or fetal-maternal infective morbidity. Labor induction for medical reasons is a situation rather well-controlled by the combination: "oxytocin-amniotomy" when the cervix is favorably open. However, new induction techniques are currently under study, especially vaginal administration of PGE2 which presents the advantage of being simple to administer and better accepted by the patients. This study compared the classical technique, oxytocin perfusion and early artificial rupture of the membranes, with the vaginal administration of PGE2 gel (first dose: 1 mg, second dose 1 or 2 mg, six hours later). The success rate of both techniques is comparable, approximately 70 p. cent. Also, the times between amniotomy and delivery are identical, approximately 5 hours. On the contrary, the lapses of time between the onset of the induction and the delivery, vary significantly, being always longer in the PGE2 group. However, the dose of vaginal PGE2 gel as well as the time of artificial membrane rupture could be modified in order to decrease the delay of the effect. With the participation of four Swiss obstetric clinics, medically indicated inductions of birth (with living fetuses) were performed using a new, stable PGE2 gel, and documented according to a uniform protocol. The study was conducted to investigate the efficacy of 0.5 mg of PGE2, in 2.5 ml of a vehicle (Triacetin) not yet commercially available, for local cervical maturation (n = 41). Thirty-nine patients selected by prospective randomization, in whom birth was induced conventionally, served as a control group. The efficiency of the prostaglandin gel alone or respectively with additional administration of oxytocin was evaluated on the basis of the clear changes in the cervical findings observed within 12 or respectively 24 hours, the spontaneous births, or, in the case of cesarean deliveries, according to the pelvic score. Application of PGE2 alone led to impressive changes of the cervix score and, in 34 of the 41 cases, to regular contractions after an average time of 87 minutes. After 12 hours, prior to administration of oxytocin, 43% of the patients were already delivered. The combination of locally applied PGE2 gel with conventional oxytocin induction significantly increases the number of successful inductions. The percentage of unsuccessfully attempted inductions was reduced to 24% in the PGE2 gel group as compared to 44% in the control group. In a randomized controlled study of 100 women of low parity and favourable induction features, induction of labour by means of a single vaginal tablet containing 3 mg of prostaglandin E2 (PGE2) was compared with the conventional method of amniotomy and intravenous oxytocin. Four of the patients (8%) who received the prostaglandin tablet required additional intravenous oxytocin to achieve delivery. The prostaglandin group had a longer mean overall induction-delivery interval but a shorter amniotomy-delivery interval than the oxytocin group. One patient in the PGE2 group and two in the oxytocin group required caesarean section. The PGE2 treated patients expressed a higher level of satisfaction with their method of induction, they required less analgesia, had less blood loss at delivery and their babies had a lower incidence of neonatal jaundice. Two groups of healthy women at term, who were not in labor 3 hours after premature rupture of the membranes, were studied. In one group labor induction with oral prostaglandin E2 (PGE2) was begun 3 hours after rupture, and in the other group intravenous oxytocin induction was begun 12 hours after rupture. PGE2 was successful in initiating active labor in 88% of women treated. Of the women who were observed for 12 hours, one-half began labor spontaneously during that time. Women in whom labor was induced with PGE2 given 3 hours after rupture of the membranes had a shorter interval of rupture to delivery, a lower cesarean section rate, and shorter postpartum hospitalization. Although significant bradycardia did not occur in fetuses of those women given PGE2, 10% of infants whose mothers were receiving oxytocin were delivered by cesarean section for this reason. It is concluded that oral PGE2 is safe and effective for induction of labor in women with premature membrane rupture. The benefits, to both mother and fetus, of a shorter latent period are discussed. Delivery with an unfavorable cervix using oxytocin is frequently unsuccessful. Used widely in Europe and increasingly in this country, locally applied prostaglandin E2 appears to improve labor induction. The present study prospectively evaluated the efficacy and safety of a prostaglandin gel (0.5 mg) placed intracervically. The use of the gel, when compared to a control group who received no pretreatment prior to labor induction, resulted in improved Bishop scores (7.5 +/- 1.0 vs. 1.8 +/- 0.3, P less than 0.0001), reduced induction to delivery intervals (10.1 +/- 2.1 vs. 20.6 +/- 2.0 hours), reduced oxytocin infusion duration (10.0 +/- 2.1 vs. 20.0 +/- 2.3 hours. P less than 0.0001) resulting in a lower cesarean delivery rate, 26 vs. 47 per cent (P greater than 0.05). Thirty-two per cent of patients receiving the prostaglandin gel labored and delivered within 12 hours and required no oxytocin. In addition, the use of prostaglandin E2 gel appeared safe in that no patient experienced an untoward reaction. Two cases of uterine hyperstimulation occurred that required uterine tocolysis but were not associated with fetal distress. The use of prostaglandin gel appears to be a safe and effective method to improve cervical inducibility in patients undergoing induction for a variety of maternal and fetal indications. Ninety-one pregnant women with unfavourable cervix (Bishop score no higher than 6) were randomly allocated to induction of labour with either prostaglandin E2 suppositories 2.5 mg 1-2 a day or i.v. oxytocin 4-32 mU/min. The induction procedure was carried on for 2 days. For statistical comparison of efficacy, life table analysis and the logrank test were used with vaginal delivery as the aimed 'event'. Prostaglandin suppositories were more efficient after 12 h (p less than 0.025) and 24 h (p less than 0.005), whereas no difference in efficacy was observed after 48 h. Vaginal delivery was obtained within 48 h in 74% of the women in the prostaglandin group and in 70% in the oxytocin group. No difference was observed in methods of delivery or neonatal Apgar scores, though, in neonates delivered vaginally within 2 days, lowered umbilical artery blood pH values were found after prostaglandin E2 suppositories (p less than 0.05). The patients attitude toward the method of induction was highly in favour of the prostaglandin suppositories. Prostaglandin E2 suppositories are considered excellent for induction of labour if delivery has to be within 24 h, whereas the two methods are equally effective after 48 h.
Induction of labour using mechanical methods results in similar caesarean section rates as prostaglandins, for a lower risk of hyperstimulation. Mechanical methods do not increase the overall number of women not delivered within 24 hours, however the proportion of multiparous women who did not achieve vaginal delivery within 24 hours was higher when compared with vaginal PGE2. Compared with oxytocin, mechanical methods reduce the risk of caesarean section.