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

Abstract

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

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Induction of labour; Mifepristone; Misoprostol.