Foley catheter silicone versus latex for term outpatient induction of labour: A randomised trial

BACKGROUND: Both silicone and latex single-balloon Foley catheters are available for cervical ripening but no literature exists to compare them. Local experience suggested more frequent insertion-related accidental rupture of the membranes (acROM) with silicone. AIMS: To compare the performance of silicone versus latex catheters with respect to acROM and other outcomes. MATERIALS AND METHODS: Women undergoing outpatient Foley catheter cervical ripening were randomised to a silicone or latex catheter. Data were collected on the primary outcome, acROM, and secondary outcomes including catheter insertion failure, unplanned hospital admission and patient-reported discomfort, together with intrapartum fever and antibiotics for suspected chorioamnionitis along with general obstetric and neonatal outcomes. RESULTS: Among 534 recruited women, acROM was significantly more common with a silicone compared to a latex catheter at 7.2% (19/265) versus 1.5% (4/269) (relative risk (RR) 4.8; 95% CI 1.7-14.0). Insertion failure was significantly less common with silicone than latex at 2.6% (7/265) versus 9.3% (25/269) (RR 0.3; 95% CI 0.1-0.6). However, when the alternative catheter was subsequently tried, the final failure rates were 1.9% silicone (5/265) versus 2.6% latex (7/269). Insertion-related hospital admission was higher with silicone at 9.4% (25/265) than latex at 4.8% (13/269) (RR 2.1; 95% CI 1.1-4.1). All other obstetric outcomes were similar between the groups. CONCLUSION: When used for cervical ripening, a silicone Foley catheter is associated with a higher rate of acROM than a latex catheter but a lower rate of insertion failure. It may, therefore, be reasonable to attempt insertion with a latex catheter initially and manage insertion failures with a silicone catheter.