Pre-Induction Cervical Ripening Using a Transcervical Foley Catheter Combined with ISMN Vaginal Tablets for Vaginal Birth after Previous Caesarean Section (VBAC)—A Comparative Study

Objective: To compare the effectiveness, safety and client acceptability of concurrent application of transcervical Foley catheter with vaginal ISMN-sustained release (SR) 60 mg tablet versus transcervical Foley catheter alone for pre-induction cervical ripening in women who are undergoing Vaginal birth after C-section (VBAC). Method: A prospective single blind randomized control study was carried out including 110 pregnant women who had unfavorable cervix (MBS less than 6) at 40 weeks and 3 days of gestation. The two groups received either the trans-cervical foley catheter with a vaginal ISMN 60 mg sustained release (SR) tablet on 40 weeks and 3 days (Treatment arm 1, n = 57), or trans-cervical Foley alone on 40 weeks and 3 days (Treatment arm 2, n = 53). Results: At 40 weeks + 3 days gestation, the mean age, mean parity and the mean modified Bishop Score (MBS) were comparable among the two treatment groups. Majority (n = 98, 89.1%) remained without spontaneously establishing labour at 24 hours of intervention. The difference in mean MBS at 40 weeks + 4 days (24-hours following the intervention) in the two groups was statistically not significant (P > 0.05). The group who received concurrent ISMN vaginal tablets achieved a higher number of successful VBACs (n = 33, 62.3%) over the group who received the Foley catheter only method (n = 29, 50.9%), however, not statistically significant (P > 0.05). Conclusions: The concurrent use of vaginal ISMN tablets (60 mg SR) with a transcervical Foley catheter failed to show higher effectiveness compared to a transcervical Foley catheter alone as an induction method.