The optimal strategy for induction of labour (IOL) in cases of prelabour rupture of membranes (PROM) with an unfavourable cervix is elusive. No study conducted in nulliparous women has shown any one induction method to be superior to any other. In this project, we seek to determine whether IOL with balloon catheter and oxytocin can (1) increase rate of delivery

We are conducting a multicentre, randomised, controlled, open-label therapeutic trial with two parallel arms on nulliparous women with unfavourable cervix showing PROM at term without spontaneous labour.

After 12 hours of PROM, women are randomly assigned to one of two study groups. One group is treated with a balloon catheter for 12 hours, with oxytocin administered after 6 hours. If the balloon is expelled earlier than 6 hours after insertion and the cervix is still unfavourable, another balloon is placed. The other group (control) is treated with 25 µg oral PGE1 every 2 hours until labour starts. After a maximum of eight administrations and a timelapse of 4 hours, if there are no effective uterine contractions, the induction is continued with oxytocin infusion and epidural analgesia if the patient requests it. A total of 520 women will be recruited in five university hospitals in France and randomised at a 1:1 ratio with stratification by study centre.

Main inclusion criteria are nulliparous women with gestational age ≥37 weeks, PROM without labour beyond 12 hours, unfavourable cervix (Bishop score

The hierarchical primary endpoints are: (1) Proportion of patients vaginally delivered

The RUBAPRO2 trial was approved by the French national agency for drug safety and committee for protection of persons involved in biomedical research on 15 September 2022. Informed written consent will be obtained from all participants.

NCT05568745.