A comparison of four methods of ripening the unfavourable cervix. A comparison of the efficacy and safety of extra-amniotic prostaglandin E2 and intravenous prostaglandin E2 for the induction of labour in patients with unripe cervices. Induction of labour by balloon catheter with extra-amniotic saline infusion (BCEAS): a randomised comparison with PGE2 vaginal pessaries. Extra-amniotic prostaglandin E2 gel vs. amniotomy for elective induction of labour. Extra-amniotic saline infusion versus extra-amniotic prostaglandin F2alpha for cervical ripening and induction of labor.
A comparison was made between four methods of ripening the unfavourable cervix (extra-amniotic prostaglandin E2 gel, oral prostaglandin E2, intravaginal prostaglandin E2 and intravenous oxytocin) in a clinical trial involving 60 primigravidae. In all groups there was an improvement in cervical status. This was significantly greater in those patients who received extra-amniotic prostaglandin gel and they also showed significant decreases in the mean induction-delivery interval and in the incidence of Caesarean section. In a study comparing intravenous prostaglandin E2 (PGE2) with extra-amniotic PGE2 for the induction of labour, in patients with unfavourable induction features, we found no difference between the two methods in either safety or efficacy. However, we would not recommend the use of the extra-amninotic route as a routine method because of some technical difficulties. A new method for induction of labour--balloon catheter with extra-amniotic saline infusion (BCEAS)--is evaluated in randomised comparison with prostaglandin E2 (PGE2) in vaginal pessaries.
                One-hundred and nine pregnant women with unfavourable cervices.
                The efficiency of inducing vaginal delivery and the level of 'disadvantages following induction of labour' (DisFIL scorings).
                Overall, BCEAS was less efficient inducing vaginal delivery than vaginal PGE2 (P < 0.01) because of a significant difference among parous women (P < 0.01). In the (larger) primiparous women group, and particularly in the subgroup of these having very low pelvic scores (Lange score, < or = 3), the efficiencies of the two methods were equal (P = 0.06) and P = 0.55, respectively). The levels of DisFIL scorings were not significantly different. However, higher rates of caesarean section followed BCEAS than PGE2 (29% and 10%, respectively; P < 0.05). Serious infectious complications were not recorded following BCEAS. No difference was apparent in the status of the neonates (judging from Apgar scores and umbilical artery pH and SBE). The women, delivering vaginally, commented the two methods equally favourably.
                BCEAS was less efficacious than vaginal PGE2 pessaries, though among primiparous women, especially those with very unfavourable cervices, the difference was not significant. Further refinements of the method are suggested. A randomized study was performed to compare three methods of labour induction in 143 clinically normal women (43 nulliparas) at term: amniotomy with or without intravenous oxytocin, extra-amniotic prostaglandin (PG) E2 gel, and extra-amniotic PGE2 gel plus an indwelling catheter. The three methods appeared to be comparable in effect and all of them were perinatally safe. Thus, if preference is given to keeping the ovular sac intact during the early phase of induced labour, extra-amniotic PGE2 in viscous gel, either with or without an indwelling catheter,. can replace the classical induction technique. 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.