Mifepristone versus balloon catheter for labor induction: a cohort study

Abstract

Objective: to compare trans-cervical balloon catheter with oral administration of mifepristone for induction of labor.

Methods: Retrospective cohort study including a total of 325 patients; labor was induced with Foley catheter (group I, n = 220) or mifepristone (group II, n = 105). We selected patients with cervical ripening ≤5 cm according to Bishop score (n = 208) and divided into 2 subgroups depending on the parity: group I, primiparous with a Bishop score of ≤5, n = 70 - I (1, ≤5); group I, multiparous with a Bishop score of ≤5, n = 44 - I (2,≤5); group II, primiparous with a Bishop score of ≤5, n = 65 - II (1, ≤5); group II, multiparous with a Bishop score of ≤5, n = 29 - II (2, ≤5). Frequencies and percentages were presented using analysis of variance.

Results: Vaginal delivery occurred more frequently in patients induced by mifepristone (76.5%) vs. Foley catheter (74.5%). However, vaginal delivery within 24 h from the onset of induction occurred in the majority of patients in the Foley catheter groups: 39 (55.7%) and 28 (63.6%) versus 15 (23.1%) and 6 (20.7%) in groups induced with mifepristone. The frequency of cesarean section in the primiparas induced using a Foley catheter was 14%, with the use of mifepristone 21%. However, all multiparas induced with mifepristone delivered vaginally, in contrast to 30.7% of multiparas with the placement of a Foley catheter which required a cesarean delivery.

Conclusion: Comparison of the effectiveness of induction of labor with the use of mifepristone and an intracervical balloon Foley catheter showed that both of these methods are successful, with more deliveries within the first 24 hrs achieved by using Foley catheter. The results of this study support the postulate that the success of an induction is largely dependent on the degree of cervical ripening and parity.

Keywords: Labor induction; balloon catheter; mifepristone.