BACKGROUND AND PURPOSE:

• Beckmann et al. (BJOG, 2020) compared clinical outcomes following labor induction using outpatient balloon catheter vs inpatient prostaglandin (PG)

METHODS:

• Pragmatic multicenter randomized controlled trial RCT
• Participants
  • Uncomplicated, cephalic, ≥37w0d, singleton pregnancies undergoing IOL for low-risk indications including
    • Post-term | Advanced maternal age | “Social” reasons
• Exclusion
  • Congenital anomalies | Complicated pregnancies (e.g. SGA) | Previous Cesarean | Modified Bishops Score (MBS) ≥7
• Interventions (all women had NST prior to intervention)
  • Use of balloon catheter for IOL as an outpatient
    • Double-balloon catheter inserted (80 ml saline instillation) and sent home following 30 minute observation period
    • Post-insertion NST not routinely performed prior to discharge home
    • Returned in 12 hours for follow up and review
  • Use of PG for IOL as an inpatient (Obstetrician choice of PG)
    • 2 mg dinoprostone vaginal gel (Prostin) or 10 mg dinoprostone controlled-release vaginal tape (Cervidil)
• Primary outcome: Composite neonatal measure ≥1 of the following
  • Nursery admission | Intubation | Cardiac compressions | Acidemia (cord pH <7.10) | HIE | Seizure | Infection | Pulmonary hypertension | Stillbirth | Death
• Secondary outcomes
  • Included mode of birth, pain scores and duration of labor were also evaluated
• Statistical analysis
  • Sample size required: 2500
  • To detect a 31% reduction in the composite neonatal outcome (10.0% to 6.9%)
  • 80% power 80% and type 1 error of 0.05

RESULTS:

• 695 participants included | Study stopped at time of interim analysis by Data and Safety Monitoring Committee due to (1) slow rate of recruitment (2) loss of patients from time of consent to randomization and (3) very low rates of adverse outcomes
  • Balloon group: 347 women
  • PG group: 348 women
• There were no significant differences for the following
  • Composite neonatal measure
    • Balloon: 18.6%
    • PG: 25.8%
    • Relative risk (RR) 0.77 (95% CI 0.51 to 1.02; P=0.070)
  • Cord arterial pH <7.10 (P=0.072)
    • Balloon: 3.5%
    • PG: 9.2%
  • Nursery admissions (P=0.379)
    • Balloon: 12.6%
    • PG: 15.5%
  • Neonatal antibiotic use (P=0.103)
    • Balloon: 12.1%
    • PG: 17.6%
  • Cesarean delivery (P=0.240)
    • Balloon: 32.6%
    • PG: 25.8%
• Nulliparous women in the balloon group had lower rates of the primary outcome (P=0.032)
  • Balloon: 20.4%
  • PG: 31.0%
• Parous women in the balloon group were less likely to have an unassisted vaginal birth (P=0.045)
  • Balloon: 77.6%
  • PG: 92.3%
• Parous women with a favorable cervix and in the balloon group had higher rates of cesarean than those in the PG group (21.2% vs 2.4%; P =0.009)
• No differences were detected for other secondary outcomes such as
  • PPH | Analgesic use | Maternal antibiotic use | Cord prolapse | Meconium stained fluid
  • Uterine hyperstimulation: Only occurred in the PG group (3.0% versus 0%; P =0.029)
• Only 6% of women in the balloon arm returned to hospital because of labor onset

CONCLUSION:

• Outpatient balloon catheter for IOL may be superior to inpatient PG for nulliparous women resulting in decreased composite adverse neonatal outcomes
• For parous women, similar benefits were not seen and there may be increased risk for cesarean with a favorable cervix

Learn More – Primary Sources:

Induction of labour using prostaglandin E2 as an inpatient versus balloon catheter as an outpatient: a multicentre randomised controlled trial

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