Cervical Ripening Balloon for Induction of Labour in High Risk Pregnancies

The Cervical Ripening Balloon (CRB) is a novel mechanical method for induction of labour (IOL), reducing the risks of hyperstimulation associated with pharmacological methods. However, there remains a paucity of literature on its application in high risk mothers, who have an elevated risk of uterine rupture, namely those with previous scars and grandmultiparity.

A retrospective study on IOL using the CRB in women with previous caesarean section or grandmultiparity between January 2014 and March 2015. All cases were identified from the Sarawak General Hospital CRB request registry. Individual admission notes were traced and data extracted using a standardised proforma.

The overall success rate of vaginal delivery after IOL was 50%, although this increases to about two-thirds when sub analysis was performed in women with previous tested scars and the unscarred, grandmultiparous woman. There was a significant change in Bishop score prior to insertion and after removal of the CRB. The Bishop score increased by a score of 3.2 (95% CI 2.8-3.6), which was statistically significant (p<0.01) and occurred across both subgroups, not limited to the grandmultipara. There were no cases of hyperstimulation but one case of intrapartum fever and scar dehiscence each (1.4%). Notably, there were two cases of change in lie/presentation after CRB insertion.

CRB adds to the obstetricians' armamentarium and appears to provide a reasonable alternative for the IOL in women at high risk of uterine rupture. Rates of hyperstimulation, maternal infection and scar dehiscence are low and hence appeals to the user.