• Gomez Slagle et al. (AJOG, 2022) evaluated whether amniotomy within 1 hour of Foley catheter expulsion reduces the duration of labor among individuals undergoing combined misoprostol and Foley catheter labor induction at term 

METHODS: 

• Randomized clinical trial 
• Participants 
  • Undergoing Foley catheter and misoprostol induction at ≥37 weeks  
  • Singleton
• Interventions 
  • Early artificial rupture of membranes 
    • Amniotomy within 1 hour of Foley catheter expulsion 
  • Expectant management  
• Study design  
  • Intent-to-treat strategy 
  • Adjustments: Age | BMI | Parity | Mode of delivery | Bishop score 
  • Interaction between randomization group and parity also analyzed  
• Sample size  
  • Power 80% | Assuming 10% drop out, 160 patients to detect a 4-hour reduction in delivery time  
• Primary outcome 
  • Time to delivery: Time from Foley catheter expulsion to delivery 

RESULTS: 

• Early artificial rupture: 79 participants | Expectant management: 81 participants 
• Early artificial rupture of membranes achieved a faster median time to delivery than expectant management (P<0.001) 
  • Early artificial rupture of membranes: 11.1 hours (IQR, 6.25 to 17.1) 
  • Expectant management: 19.8 hours (IQR, 13.2 to 26.2) 
• In addition, a greater percentage of individuals in the early artificial rupture of membranes group delivered within 24 hours (P=0.03) 
  • Early artificial rupture of membranes: 86% 
  • Expectant management: 70% 
• There was no difference in the cesarean delivery rate between the 2 groups (P=0.25) 
  • Early artificial rupture of membranes: 22% 
  • Expectant management: 31% 
• Individuals delivered 2.3 times faster following early artificial rupture of membranes 
  • Hazard ratio 2.3 (95% CI, 1.5 to 3.4); P<0.001 
• There were no significant differences in maternal or neonatal outcomes 

• For women undergoing induction of labor, early artificial rupture of membranes within 1 hour of Foley catheter expulsion led to a 2.3 times faster time-to-delivery  
• Study limitation includes lack of blinding  
  • However, time-to-delivery is an objective primary outcome measure  
• The authors state 

Therefore, amniotomy within 1 hour of Foley catheter expulsion may be considered among individuals undergoing a combined pharmacologic and mechanical induction at term 

Learn More – Primary Sources: 

Early vs expectant artificial rupture of membranes following Foley catheter ripening: a randomized controlled trial 

Related ObG Topics:

RCT Results: Balloon Catheter Removal at 6 vs 12 Hours and Time to Delivery

Does Adding a Foley to Misoprostol Decrease Time to Delivery?

Meta-Analysis: Does Outpatient Cervical Ripening with Balloon Catheter Decrease Time Spent on Labor and Delivery?

How Safe and Effective is Early Amniotomy During Labor Induction?