Cervical Ripening Balloon Increases Intra-Amniotic Infection Risk in PROM Inductions Compared to Pharmacologic Methods

For individuals experiencing prelabor rupture of membranes (PROM), timely labor induction is often necessary to reduce the risk of maternal and neonatal complications, particularly intra-amniotic infection. Current induction methods include mechanical cervical ripening, such as the cervical ripening balloon, and pharmacologic agents like oxytocin or prostaglandins. While both aim to achieve cervical dilation and uterine contractions, concerns persist regarding their comparative safety profiles, especially concerning infectious morbidity. Understanding the differential risk of intra-amniotic infection associated with these methods is crucial for optimizing clinical practice and improving patient outcomes in PROM management.

This systematic review and meta-analysis evaluated the odds of intra-amniotic infection in individuals with PROM who underwent labor induction with a cervical ripening balloon compared to pharmacologic methods. Researchers systematically searched MEDLINE, EMBASE, Web of Science, Cochrane Library, and ClinicalTrials.gov for relevant studies published between 2002 and 2023. Two independent reviewers screened 14 studies (eight randomized controlled trials and six retrospective cohort studies) comprising 2,165 participants. Data extraction focused on the incidence of intra-amniotic infection, and odds ratios (OR) with 95% CIs were pooled using a random-effects model to assess the comparative risk.

The pooled weighted rate of intra-amniotic infection was 9.4% (95% CI, 5.9-13.6%) with the cervical ripening balloon and 7.0% (95% CI, 4.4-10.2%) with pharmacologic methods, yielding an overall OR of 1.46 (95% CI, 0.90-2.37; I2 45%). However, when analyses were restricted to the eight randomized controlled trials, the cervical ripening balloon was significantly associated with an increased risk of intra-amniotic infection (OR 1.84; 95% CI, 1.03-3.28; I2 0%). This finding suggests a robust association in higher-quality evidence.

In contrast, no significant association was observed in the six cohort studies (OR 1.25; 95% CI, 0.50-3.13; I2 68%), indicating substantial heterogeneity in this subgroup. Rates of intra-amniotic infection were similar when comparing the cervical ripening balloon specifically to prostaglandin (OR 1.27; 95% CI, 0.60-2.70; I2 54%) and to oxytocin (OR 1.66; 95% CI, 0.74-3.73; I2 0%), though these subgroup analyses did not reach statistical significance for increased risk.