[The effect of 25 micrograms misoprostol on induction of labor in late pregnancy]

To determine the efficacy and safety of 25 micrograms misoprostol for labor induction in the third trimester of pregnancy.

48 term pregnant women with single pregnant vertex present intact membrane were selected in study group. All case in study group indications for labor induction, without contra-indication of labor induction and misoprostol. The 48 women were randomly assigned A(25 micrograms) and B(50 micrograms) misoprostol groups. Misoprostol was placed in the posterior vaginal fornix every 4 to 6 hours. The maximum dose in 24 hours is 200 micrograms. Misoprostol was not given after either spontaneous rupture of membrane or beginning of active labor.

The sucesess rate of induction labor was groups 77.8%, 81.0% in group A and B, respectively. The average duration from administration of misoprostol to start of labor in two groups was 796.9 +/- 359.9 minutes and 807.4 +/- 405.2 minutes, respectively; the average duration from start of misoprostol use to vaginal delivery was 978.6 +/- 464.4 minutes, 977.5 +/- 421.4 minutes, respectively. The incidence of vaginal delivery had no statistics significant difference between two groups (P > 0.05). The incidence of hypertonic uterine contraction or hypertonic contractionchysystole with abnormal pattern of fetal monitoring in group A was lower than that of group B, but there was no significant difference (P > 0.05).

25 micrograms misoprostol is an efficient and safe dosage for labor induction in term pregnancy.