Sublingual misoprostol for labor induction: a randomized clinical trial

Abstract

Objective: To compare the effectiveness of 50 microg compared with 100 microg of repetitive misoprostol dosages administered sublingually for labor induction.

Methods: Two hundred twelve women who presented with an indication for cervical ripening and labor induction were randomly assigned to 50 microg or 100 microg of misoprostol tablets administered sublingually with double masking of treatment group dose allocation. The primary outcome was the interval from start of induction to vaginal delivery.

Results: Among the 203 evaluable participants, 102 were randomly assigned to the 50-microg group and 101 to the 100-microg group. The proportion of patients who delivered vaginally in less than 12 hours and less than 24 hours was significantly higher in the 100-microg group: 28% and 63% in the 100-microg group compared with 15% and 36% in the 50-microg group, respectively (P = .01 and P = .001). The incidence of tachysystole was significantly higher in the 100-microg group (P = .02). The incidence of hyperstimulation syndrome was higher in the 100-microg group, but not statistically significant (P = .46). With respect to the proportion of patients delivered after a single dose, mode of delivery, and perinatal outcome, no significant differences between treatment groups were observed. Regarding the need for oxytocin augmentation, 61% required augmentation in the 100-microg group compared with 81% in the 50-microg group (P = .002).

Conclusion: One hundred micrograms of sublingual misoprostol is more effective than 50 microg of sublingual misoprostol, but is associated with a higher incidence of tachysystole and uterine hyperstimulation syndrome.

Level of evidence: I.