Single-balloon versus double-balloon catheters for cervical ripening before induction of labour in term singleton pregnancies: a systematic review of randomized controlled trials

Abstract

Mechanical balloon catheters are widely used for cervical ripening before induction of labour in women with an unfavourable cervix. The single-balloon Foley catheter and the double-balloon cervical ripening catheter are commonly used in clinical practice. However, evidence regarding their comparative effectiveness and safety remains inconsistent. A systematic review of randomized controlled trials was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA 2020) statement. A systematic search of the PubMed database was performed from database inception to 31 May 2026. Randomized controlled trials comparing single-balloon and double-balloon catheters for cervical ripening and induction of labour in term singleton pregnancies were included. Data on maternal and neonatal outcomes were extracted and synthesized narratively because of clinical and methodological heterogeneity among the included studies. Five randomized controlled trials involving 835 women met the inclusion criteria. Both catheter types were effective for cervical ripening and labour induction. Improvements in bishop score, induction-to-delivery interval, and mode of delivery varied across the included studies. Some trials reported shorter induction-to-delivery intervals or greater cervical ripening with the double-balloon catheter, whereas others found similar outcomes between the two devices. Maternal and neonatal outcomes, including caesarean section rates, APGAR scores, and neonatal intensive care unit admissions, were generally comparable. Current evidence does not demonstrate consistent superiority of either the single-balloon or the double-balloon catheter for cervical ripening and induction of labour in term singleton pregnancies. Both devices appear to be safe and effective mechanical methods. Catheter selection should be guided by clinical judgement, patient characteristics, resource availability, local practice, and cost. Further well-designed multicentre randomized controlled trials with standardized outcome measures are needed to strengthen the available evidence.