Randomised trial of one versus two doses of prostaglandin E2 for induction of labour: 1. Clinical outcome. Mid-trimester termination of pregnancy--a randomised controlled trial of two prostaglandin regimens. Labor induction with vaginal misoprostol and extra-amniotic prostaglandin F2alpha gel. A randomised controlled trial of an oral solution of prostaglandin E2 and oral oxytocin used immediately after low amniotomy for induction of labour in the presence of a favourable cervix. Extra-amniotic saline infusion versus extra-amniotic prostaglandin F2alpha for cervical ripening and induction of labor.
To compare the outcome of induction of labour using a single versus two doses of prostaglandin E2 vaginal gel.
                Prospective randomised trial comparing a single dose of prostaglandin E2 2 mg vaginal gel in the evening with two doses of prostaglandin E2 (2 mg), the second being given after six hours if labour had not started or the cervix was still unripe. Amniotomy and oxytocin titration were performed when necessary for both protocols. Nulliparae and multiparae were analysed separately by treatment intention.
                A maternity unit in a district general hospital annually delivering > 6000 women.
                Nine-hundred and ninety-five women with viable singleton pregnancies and cephalic presentation at term without previous history of caesarean section who were advised to have labour induced with prostaglandins.
                Need for formal amniotomy and oxytocin augmentation, use of epidural analgesia, rate of intrapartum interventions, mode of delivery and neonatal condition at birth.
                For multiparae two prostaglandin doses resulted in a significant reduction in the need for formal amniotomy (15% vs 30%) and oxytocin augmentation (28% vs 38%) compared with those receiving a single dose; there was no significant difference for nulliparae. Other interventions during labour, length of labour, and mode of delivery were similar in both protocols. Failed induction occurred only in nulliparae and was similar in both protocols (1%). There was no discernible difference in fetal or neonatal outcome although passage of meconium was more common in labour if two doses had been given, as was neonatal admission to the special care baby unit.
                There was little clinical benefit from inducing labour with two doses of prostaglandin E2 at a six-hour interval, compared with a single dose. There may be financial advantages with a two-dose regimen. To determine the more applicable of two ways of prostaglandin induction currently in use in second trimester induced abortions for congenital or chromosomal abnormalities.
                A prospective randomised controlled trial.
                Department of Obstetrics and Gynaecology, Tygerberg Hospital, CP.
                Twenty consecutive patients admitted for termination of pregnancy for congenital or chromosomal abnormalities between 14 and 26 weeks' pregnancy duration.
                Patients were randomly selected to receive either 1.5 mg prostaglandin E2 (PGE2) gel extra-amniotically or 25 mg prostaglandin F2 alpha (PGF2 alpha) intra-amniotically. Patients in both groups received oxytocin to a maximum dosage of 120 mU per minute if they had not aborted 18 hours after the original administration of either prostaglandin regimen. If abortion had not taken place 36 hours after commencement of treatment, management was considered unsuccessful.
                Proportion of successful inductions and complications.
                Complications of management were rare and did not differ between the two management groups. However, there were significantly more failures in the group who received intra-amniotic PGF2 alpha (7 v. 2 patients) as well as a significantly higher need for oxytocin in this group (10 v. 4 patients).
                With promising drugs such as prostaglandin analogues and anti-progesterones not universally available, methods of induction suitable to the local situation should be sought. Extra-amniotic PGE2 seems more suitable than intra-amniotic PGF2 alpha because of a shorter induction-to-delivery time without increased morbidity. To compare the effectiveness of vaginally administered misoprostol with extra-amniotic prostaglandin F2alpha (PGF2alpha) gel for induction of labor.
                A randomized controlled trial, with women allocated to receive either misoprostol 50 microg intra-vaginally or extra-amniotic PGF2alpha gel 5 mg, was conducted in Harare Maternity Hospital. A total of 152 women were admitted for induction of labor with a term singleton, pregnancy and cephalic presentation were recruited. The main outcome was duration of induction.
                There were no differences in the characteristics of women in the two groups at recruitment. In the misoprostol group there was a significantly reduced need for augmentation of labor with oxytocin (OR=0.36; 95% C.I. 0.17-0.73) and delivery by cesarean section for failure to progress (OR=0.11; 95% C.I. 0.00-0.88). The risk for duration of induction to vaginal delivery exceeding 12, 18 or 24 h was reduced by 18%, 38% and 68%, respectively, but only the risk for duration >24 h was significantly reduced (OR=0.32; 95%C.I. 0.11-0.91). The mean duration of induction was shorter in the misoprostol group, 15.2 vs. 23.6 h (P=0.02). There were no differences in fetal outcome.
                Misoprostol 50 microg was associated with less use of oxytocin in labor, a shorter induction to delivery interval and fewer cesarean sections for failure to progress when compared with extra-amniotic PGF2alpha gel. A randomised controlled trial was carried out in 50 primigravidae and 50 multigravidae to compare the effectiveness in induction of labour after low amniotomy of prostaglandin E2, given as an oral solution, and oxytocin, given as buccal tablets. The results showed that in dosages recommended by the manufacturers, both oxytocic preparations were almost equally effective. With oral oxytocin, once labour had been established and dosage was left to the discretion of the staff, there appeared to be a potentially dangerous tendency to continue giving large doses despite adequate uterine contractions. The authors comment that this was probably the reason why oxytocin-treated multigravidae having normal deliveries within 24 hours had labours significantly shorter on average than those of other successfully induced patients. To compare the effectiveness of extra-amniotic saline infusion versus extra-amniotic prostaglandin F2alpha for cervical ripening, induction of labor and achievement of vaginal delivery in patients with unfavorable cervices.
                A randomized trial of extra-amniotic saline infusion versus extra-amniotic prostaglandin F2alpha performed at Harare Central Hospital Maternity Unit, Zimbabwe. One hundred and sixty-four patients were recruited from those referred to Harare Central Hospital Maternity Unit who required induction of labor for either maternal or fetal indications.
                162 patients (extra-amniotic PgF2alpha group, N = 81; extra-amniotic saline infusion group, N = 81) had complete information. Two patients (one from each group) were lost to follow up. The demographic characteristics of the patients and the indications for induction were not statistically different. There was a marginally statistically significant difference in the change of Bishop Score in favor of the extra-amniotic saline infusion (4.0, S.D. = 1.4) as compared to (4.5, S.D. = 1.5) for extra-amniotic PgF2alpha (P value = 0.047). All other parameters showed no statistically significant differences. Maternal and fetal complications were minimal and not significantly different. Extra-amniotic saline infusion was however almost six times cheaper than PgF2alpha.
                Extra-amniotic saline infusion is as effective as PgF2alpha, safe, but much cheaper than PgF2alpha and should be seriously considered as a method of first choice in resource-poor settings.
The studies in this review are limited by sample size which are often divided into multiple comparison groups. Most comparisons showed no significant differences, with wide confidence intervals. Although extra-amniotic prostaglandins may be as effective as other modalities in initiating labour, there is little conclusive information from this review to guide clinical practice. An adequately powered randomised controlled trial would be useful to determine if the use of extra-amniotic prostaglandins would lower the rate of caesarean section.