title: 30 mL Single- versus 80 mL double-balloon catheter for pre-induction cervical ripening: a randomized controlled trial.
abstract: OBJECTIVE
  To compare the efficacy of an 80 mL double-balloon catheter versus a 30 mL single-balloon catheter for pre-induction cervical ripening.
  
  
  METHODS
  We performed a randomized controlled trial of women ≥18 years with a singleton, vertex pregnancy, a reactive non-stress test, and a Bishop score ≤5 comparing an 80 mL double- versus a 30 mL single-balloon catheters for cervical ripening. Women were randomly assigned to the two catheter types, stratified 1:1 by nulliparity or multiparity. The primary outcome was achieving a Bishop score ≥6 at the time of catheter expulsion or removal assessed by chi-squared, stratified by parity.
  
  
  RESULTS
  A total of 98 women were included in the analysis (50 in the 80 mL double and 48 in the 30 mL single-balloon catheter groups). Among nulliparous women, a greater proportion of those randomized to the 80 mL double achieved a Bishop score ≥6 at time of catheter removal (88.0% versus 28.0%; p ≤ 0.001) and delivered vaginally (60.0% versus 32.0%; p = 0.047) compared to those with the 30 mL single-balloon catheter. We found no difference by catheter type in achieving a Bishop score ≥6 or vaginal delivery among multiparous women.
  
  
  CONCLUSIONS
  These findings suggest the 80 mL double-balloon catheter is more effective than the 30 mL single-balloon catheter for pre-induction cervical ripening and achieving a vaginal delivery in nulliparous women.
authors: Kara K
authors: KK
authors: Hoppe
authors: Melissa A
authors: MA
authors: Schiff
authors: Suzanne E
authors: SE
authors: Peterson
authors: Michael G
authors: MG
authors: Gravett
mesh_terms: D000328:Adult; D020070:Cervical Ripening; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000295:instrumentation* / Q000706:statistics & numerical data; D011247:Pregnancy; D055815:Young Adult