Safety and Efficacy of Oral Mifepristone in Pre-induction Cervical Ripening and Induction of Labour in Prolonged Pregnancy

To study the safety and efficacy of oral mifepristone in pre-induction cervical ripening and induction of labour in prolonged pregnancy.

This is a single blind randomized control trial. 100 women with prolonged pregnancy beyond 40 weeks and Bishop score <6 were recruited, and randomly allocated into two groups. Women who received Tab. Mifepristone 200 mg orally were assigned in Study Group (n = 50) and who received placebo orally were assigned in Control Group (n = 50) At the end of 24 h, change in the Bishop’s score was assessed and Tab. Misoprostol 25 μg was administered intravaginally every 4 h, maximum 6 doses for induction/augmentation of labour. Analysis regarding safety and efficacy of the drug was done with regards to maternal and perinatal outcome.

Among 100 subjects, 50 received mifepristone and 50 received placebo. Mean induction to delivery interval was 1,907 ± 368.4 min for Study Group versus 2,079 ± 231.6 min for Control Group. The improvement in mean Bishop score was 5.0408 ± 1.90 for Study Group compared with 3.26 ± 1.15 was for Control Group after 24 h. Mean dose of misoprostol in Study Group was 40 ± 27.2, while the same in Control Group was 52 ± 19.46. Eight (16 %) women in Study Group and two (4 %) women in Control Group delivered vaginally within 24 h without any need of augmentation. There were 6 (12 %) cesareans and 2 (4 %) instrumental deliveries in Study Group and 8 (16 %) cesareans and 5 (10 %) instrumental deliveries in the Control Group. There was no statistically significant difference in perinatal outcomes between two groups.

Mifepristone had a modest effect on cervical ripening when given 24 h prior to labour induction and appearing to reduce need for misoprostol compared with placebo.