Mifepristone vs balloon catheter for labor induction in previous cesarean: a randomized controlled trial

Abstract

Objective: To compare oral mifepristone (400 mg) with trans-cervical balloon catheter for induction of labor (IOL) in post date women with previous one cesarean section (CS).

Methods: In this randomized trial, post date pregnant women (gestation 40 weeks 5 days), with previous one low segment CS (no previous vaginal delivery) were induced either with oral mifepristone (400 mg) or balloon catheter [Foley's catheter (16 Fr); bulb filled with 30 ml normal saline]. They were re-assessed 24 and 48 h later. If at any time Bishop Score was >6; amniotomy was done, followed by oxytocin infusion. Primary outcome of the study was labor onset after first manoeuvre. Secondary outcomes were cervical ripening, need of oxytocin, vaginal delivery and CS, in two groups.

Results: From June 2012 to September 2015, we enrolled 107 women. Out of these, 57 received oral tablet mifepristone (400 mg) and 50 were inserted with balloon catheter. Labor onset after first manoeuvre was statistically significantly more in mifepristone group (37/57 vs. 13/50, respectively; p value 0.000). Bishop Score after 24 h was better in balloon catheter (p value 0.000). More women with balloon catheter required oxytocin for IOL (37/50 vs. 20/57, respectively; p value 0.000) along with higher dose [840 (320) mU vs 560 (120) mU, respectively, p value 0.000]. Failure of induction was statistically significantly higher in balloon catheter group (8 out of 50 vs. 2 out of 57, respectively, p value 0.043). There was no statistically significant difference in normal delivery or CS in either group (p value 0.242 and 0.331, respectively).

Conclusion: Oral mifepristone (400 mg) is associated with statistically significantly higher incidence of labor onset in post date pregnant women with previous one CS, as compared to balloon catheter. Both methods are primarily for cervical ripening and oxytocin should not be delayed in the absence of onset of labor.

Clinical trial registration: Clinical Trials Registry-India, www.ctri.nic.in , CTRI/2012/05/003634.

Keywords: Induction of labor; Mifepristone; Previous cesarean section; Trans-cervical balloon catheter.