Dinoprostone versus misoprostol: a randomized study of nulliparous women undergoing induction of labor

The objectives of the study were to compare the efficacy and safety of intravaginal misoprostol and intravaginal dinoprostone for induction of labor and to quantify the clinical response to suspicious cardiotocographic (CTG) readings.

One hundred and ninety-one patients were randomized to receive either 50 micro g misoprostol initially then a further identical dose 6 h later or 2 mg dinoprostone initially followed by 1 mg 6 h later, over a period of 24 h. If not in labor after 24 h, then both arms of the study would thereafter receive dinoprostone alone as per hospital protocol.

The induction to delivery interval (1047 vs. 1355 min, p = 0.01), delivery within 12 h (35.4% vs. 18.9%, p = 0.02) and delivery within 24 h (83.3% vs. 63.3%, p = 0.01) were all shorter in the misoprostol arm. There were no differences in rates of oxytocin augmentation (p = 0.47), tachysystole (p = 0.32) and hyperstimulation syndrome (p = 0.82). There was an increase in the median number of times a doctor was called to advise on a suspicious CTG in the misoprostol group (1 vs. 2 occasions, p = 0.052), but there was no difference in neonatal outcome.

Intravaginal misoprostol led to a shorter, more efficient labor, and although there was more anxiety related to the CTG, there was no increase in neonatal adverse effects.