Is expensive always better? Comparison of two induction agents for term rupture of membranes.
Parisaei M and Erskine KJ Journal of Obstetrics & Gynaecology (2008)
This was the report of a study comparing two induction agents for term rupture of membranes. The authors compared sublingual misoprostol with vaginal prostaglandinE2 [Prostin] in a randomised trial involving 57 patients: (28 women with term SRM in otherwise uncomplicated singleton pregnancies received Prostin, while 29 had Misoprostol 24 -48 hours after the time of ruptured membranes.
Once the patients started contracting, they were transferred to the delivery suite for continuous monitoring and a partographic record of labour was maintained. Spontaneous vaginal delivery was achieved in 64% of the Prostin group and 86% of the misoprostol group. The mean induction of labour to delivery time was 20.71 +/- 11.59 h in the prostin group and 13.96+/-9.90h in the misoprostol group with a p value of 0.021.
Up to 46.4% of women randomised to the Prostin group required a second dose of the drug compared to 20.7% in the Misoprostol group There were two cases of hyper stimulation recorded in the Misoprostol group compared to none in the Prostin group and Syntocinon was used in 31% of the former compared to 57% in the latter category.
The authors conclude that 50 micrograms of sublingual Misoprostol used at a maximum of twice 6 hourly for term rupture of membranes, can lead to a significant reduction in the induction-delivery time and a reduced need for oxytocin infusion when compared to vaginal Prostaglandin.
This seems to be a well conducted study, and I would agree with the authors in their statement that the study is limited by the relatively small number of patients. They have recommended further larger studies to address this.
However there are multiple well-conducted trials available in literature evaluating use of oral Misoprostol in inducing labour in term SRM. Therefore, using relatively larger doses of a drug still unlicensed for this purpose, just to switch from oral to the sublingual route which does not offer any palpable benefit, is open to question.