Outpatient balloon catheter vs inpatient prostaglandin for induction of labour (OBLIGE): a randomised controlled trial

Abstract

Abstract Background Approximately one in four pregnant women undergo an induction of labour. The purpose of this study is to investigate the clinical effectiveness, safety, and cost-effectiveness for mothers and babies of two methods of cervical ripening – inpatient care for women starting induction with vaginal prostaglandin E2 hormones, or allowing women to go home for 18 to 24 h after starting induction with a single-balloon catheter. Methods/design This is a multi-centre randomised controlled trial in New Zealand. Eligible pregnant women, with a live singleton baby in a cephalic presentation who undergo a planned induction of labour at term, will be randomised to outpatient balloon-catheter induction or in-hospital prostaglandin induction. The primary outcome is caesarean section rate. To detect a 24% relative risk reduction in caesarean rate from a baseline of 24.8%, with 80% power and 5% type 1 error, will require 1552 participants in a one to one ratio. Discussion If outpatient balloon-catheter induction reduces caesarean section rates, has additional clinical benefits, and is safe, cost-effective, and acceptable to women and clinicians, we anticipate change in induction of labour practice around the world. We think that home-based balloon-catheter induction will be welcomed as part of a patient-centred labour-induction care package for pregnant women. Trial registration Australia New Zealand Clinical Trials Registry (ANZCTR), ACTRN: 12616000739415. Registered on 6 June 2016.

Keywords

• Labour, induced
• Cervical ripening
• Balloon catheter
• Prostaglandins
• Randomised controlled trial