Most studies of labour induction with misoprostol used doses higher than 25mg and intervals of 3-4 hours. We studied a low-dose regime of 25mg misoprostol and compared its efficacy as single dose or double dose with dosing interval of 6 hours to our current regime of 3 mg dinoprostone pessary.

171 women with singleton term pregnancies and modified Bishop score (mBS) ≤ 5 were recruited and randomized into 3 arms: current dinoprostone regime, double dose misoprostol or single dose misoprostol. The primary outcome was the number of women who achieved favourable mBS>6 or active labour by Day 2. Secondary outcomes were time interval from insert to active labour or delivery, abnormal uterine activity, delivery method and adverse neonatal outcome.

Inclusion Criteria:

• singleton pregnancy, cephalic presentation, gestation greater than 37 completed weeks, no known contraindication to vaginal delivery, and Bishop score≤5.

Exclusion Criteria:

• previous caesarean section or other uterine surgery, significant maternal medical/obstetric complication in pregnancy (such as severe pre-eclampsia, significant antepartum haemorrhage), antepartum evidence of fetal compromise (such as fetal growth restriction), previous attempt at cervical priming, contraindication to receiving prostaglandins, including asthma and glaucoma.