Prostaglandin E2 vaginal gel or tablets for the induction of labour at term: a randomised controlled trial

Objective To compare the effectiveness of prostaglandin E2 (dinopristone) vaginal gel versus vaginal tablets for the induction of labour at term. Design Randomised controlled clinical trial. Setting University maternity hospital in London. Population Pregnant women with cephalic presentation undergoing induction of labour after 37 weeks of gestation. Methods Prostaglandin E2 vaginal tablets (3 mg) or vaginal gel (1 mg/2 mg) was administered at 6-hourly intervals until the cervix was suitable for amniotomy. Main outcome measures Induction to delivery interval, in minutes; rate of failed induction of labour requiring caesarean delivery. Results Eighty-two women received prostaglandin gel; 83 women received vaginal tablets. There were significant differences between the two treatment groups in the primary outcomes. The mean induction to delivery interval was significantly shorter in women who received the gel (1400 minutes, 690-2280 minutes, versus 1780 minutes, 960-2640 minutes; P = 0.03). The rate of failed induction of labour was significantly higher in women who received tablets (10.84 versus 1.22%; P = 0.01). Subanalysis showed that these differences were only representative of differences in the groups of primigravid women. There were no significant differences in any of the secondary outcomes, including the number of women who required syntocinon augmentation, the rate of uterine hyperstimulation, the need for epidural analgesia, meconium staining of liquor, the need for fetal blood sampling, or delivery by caesarean section. There were no differences in adverse maternal and neonatal outcomes. Conclusion Prostaglandin E2 vaginal gel is superior to vaginal tablets for the induction of labour.