Balloon ripening in TOLAC: no rupture signal against oxytocin or spontaneous labour

Design

Systematic review and meta-analysis, 18 observational studies and 2 RCTs

Population

28,035 observations of TOLAC after one low-transverse caesarean; 5,516 balloon exposures

Primary outcome

Complete uterine rupture

Effect

vs prostaglandins OR 0.43 (95% CI 0.26 to 0.72); vs spontaneous labour OR 1.29 (0.90 to 1.84); GRADE very low

A systematic review pooled 18 non-randomised studies and two randomised trials of trial of labour after a previous low-transverse caesarean in which a Foley or double-balloon catheter was used for cervical ripening, covering 28,035 observations and 5,516 balloon exposures. Published in AJOG on 29 September 2026.

Against prostaglandin induction, the balloon strategy was associated with lower odds of complete uterine rupture (OR 0.43, 95% CI 0.26 to 0.72), about 19 fewer ruptures per 1,000. Against oxytocin alone (OR 0.24, 0.05 to 1.18) and spontaneous labour (OR 1.29, 0.90 to 1.84) no difference was detected. Dehiscence, however, was reported more often after balloon-based induction (OR 1.86, 1.06 to 3.29).

Two cautions shape how to use this. Nearly every protocol followed the balloon with amniotomy, oxytocin or both, so the estimate describes a strategy, not the catheter alone. And certainty was rated very low throughout, because the evidence is overwhelmingly observational.

In practice this supports what many units already do: when induction is indicated after one low-transverse caesarean, mechanical ripening is a reasonable first step, with the counselling, continuous fetal monitoring and immediate theatre access that any TOLAC requires.

• When induction is indicated after one low-transverse caesarean, consider a transcervical balloon before prostaglandins
• Counsel that rupture risk remains and that the evidence is observational and of very low certainty
• Keep continuous fetal monitoring and immediate access to emergency caesarean throughout
• Document the full sequence used (balloon, amniotomy, oxytocin), since risk attaches to the strategy
• Watch for signs of dehiscence, which was reported more often after balloon-based induction

Why it matters

It reassures units that avoid prostaglandins after caesarean that mechanical ripening does not trade one rupture risk for another.

Don't overread it

Certainty was very low and the comparison with spontaneous labour is not a finding of equal safety.

The statistics, in plain English

An odds ratio of 0.43 means the odds of rupture were a little under half those with prostaglandins, which works out at roughly 19 fewer ruptures for every 1,000 inductions. The intervals against oxytocin and spontaneous labour both cross 1.0, so those data are compatible with either more or fewer ruptures; 'no difference detected' is not proof of no difference.

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