Cervical ripening and induction of labour with intravaginal prostaglandin F2 alpha

A randomised double-blind trial was done to determine the effect on cervical ripening of 50 mg intravaginal prostaglandin F2 alpha (P.G.F.2 alpha) in a methyl cellulose gel given on the evening before surgical induction of labour. Patients were given either placebo or P.G.F.2 alpha and in both groups cervical stretching and sweeping of the fetal membranes was attempted. Of the 40 control patients, 3 had gone into labour and the mean improvement in the cervical score was 1.6 before surgical induction the next morning. However, 20 of the 40 patients receiving P.G.F.2 alpha went into labour before the proposed induction and the mean change in cervical score (5.1) was significantly greater than that in the placebo group. Of the 40 patients pretreated with P.G.F.2 alpha, 37 had improved cervical scores and significantly fewer required augmentation in labour with intravenous oxytocin than in the control group. No side-effects were experienced and the patients found the treatment acceptable.