Continued versus discontinued oxytocin stimulation in the active phase of induced labour: Factors associated with unexpectedly high rates of conversion to open label oxytocin in the CONDISOX trial

Objective: To examine the factors associated with unexpectedly high rates of conversion to open label oxytocin in the CONDISOX trial of continuation versus discontinuation of oxytocin infusion during induced labour.Design: Secondary retrospective analysis of data from a prospective randomised controlled trial.Setting: Nine hospitals in Denmark and one in the Netherlands between 8 April 2016 and 30 June 2020.Population or sample: 1200 women having labour induced.Methods: Analysis of outcomes by actual management.Main outcome measures: Mode of delivery and associated variables.Results: Switching to open label oxytocin (42.4% overall) was associated with nulliparity, an unripe cervix, larger babies and higher rates of delivery by caesarean section.Conclusions: In the CONDISOX trial, slow labour was associated with features suggesting a higher 'resistance to progress', often prompting the use of open-label oxytocin infusion rather than study medication.

Automated summary

The objective of this study was to examine the factors associated with unexpectedly high rates of conversion to open label oxytocin in the CONDISOX trial. A secondary retrospective analysis of data from a prospective randomized controlled trial was conducted, and it was found that switching to open label oxytocin during induced labor was associated with nulliparity, an unripe cervix, larger babies, and higher rates of delivery by cesarean section.