Randomised trial of intravaginal misoprostol and intracervical Foley catheter for cervical ripening and induction of labour

Summary

Induction of labour may be indicated despite an unripe cervix. The purpose of this study was to compare the safety and efficacy of intravaginal misoprostol and an intracervical Foley's balloon catheter for preinduction cervical ripening and labour induction. A total of 120 patients requiring indicated induction of labour with an unfavourable cervix (Bishop's score ≤4) were randomised prospectively to receive either 50 μg intravaginal misoprostol every 6 h for a maximum of two doses, or an intracervical Foley balloon catheter for 12 h followed by an intravenous oxytocin infusion. The two arms of the study were comparable with respect to maternal age, parity, gestational age, indication for induction, and initial Bishop's scores. There were significant change in the Bishop's score in the two groups (5.9 ± 0.2 and 4.0 ± 0.2, respectively, p < 0.001) but no inter group differences. Oxytocin induction or augmentation of labour occurred more in the catheter group (95%) than in the misoprostol group (43.3%) (p < 0.0001). Induction to delivery interval was significantly shorter in the misoprostol group than in the catheter group (8.7 ± 2.4 vs 11.9 ± 2.7 h p < 0.0001). There was no significant difference noted in the caesarean or other operative delivery rates among patients in the two treatment groups. There was a higher incidence of tachysystole and hyperstimulation in the misoprostol group than in the catheter group (p < 0.03). No differences were observed between groups for meconium passage, 1- or 5-min Apgar scores <7 and admission into the neonatal intensive care unit. In conclusion, the maternal and perinatal outcomes in this study have shown no difference confirming the efficacy and safety of both methods, however we observe a decrease in the induction-to-delivery interval when misoprostol is used for this purpose.