Pre-induction cervical ripening: transcervical foley catheter versus intravaginal misoprostol

The object of this study was to compare the effectiveness of the intravaginal Misoprostol and transcervical Foley catheters as pre-induction cervical ripening agents, to estimate the proportion of patients achieving vaginal delivery and to compare the complications of labour and foetal outcome between the two groups. The study was a prospective, randomised study of pregnant women, with singleton pregnancies who presented for antenatal care and delivery at the University College Hospital (UCH), Ibadan, Nigeria. Ninety-nine patients were invited to participate and ninety-six (96) agreed. No patient withdrew from the study. The patients were assigned by means of computer-generated random numbers to receive transcervical Foley catheters (Size 16F, with 30 ml balloon capacity) or 50 microg intravaginal Misoprostol (Cytotec tablet, Searle & Co., Chicago). Fifty (50) patients received intravaginal Misoprostol and Forty-six (46) received Transcervical Foley catheters. The proportions of nulliparous, primiparous and multiparous patients were 52, 20 and 28% in the misoprostol group and 43.5, 26.1 and 30.4%, respectively, in the Foley catheter group. The time to achieve a favourable cervical status was significantly shorter in the Misoprostol group, with 98.0% of the subjects attaining Bishop score > or = 6 within 6-12 hours of insertion of the study agent, in contrast to 69.0% of the subjects in the Foley catheters group (P<0.001). Thirteen (26.6%) and three (6.5%) patients in the Misoprostol and Foley catheters groups, respectively, went into labour while undergoing cervical ripening and all had uneventful vaginal deliveries (P<0.05). The induction-delivery interval did not differ significantly between the groups. The incidence of caesarean delivery was 6.0% in the Misoprostol group compared with 2.2% in the Foley catheter group (P=0.62). Instrumental vaginal delivery rates were similar in both groups. Overall, the mode of delivery did not differ significantly between the groups. The number of neonates with 1-minute Apgar score <7 did not differ significantly in both groups and no neonate had 5-minute Apgar score <7. Meconium stained liquor was noticed in 5 (Misoprostol) vs 2 (Foley catheters) patients in labour. None of the neonates had any features suggestive of meconium aspiration. Labour complications were mainly precipitate labour {2 (Misoprostol) vs 1 (Foley catheters) } and 1 patient with transient tachysystole (> or =6 contractions in 10 minutes for two consecutive 10-minute periods) in the Misoprostol group. Hyperstimulation was not noticed in any of the patients in either arm of the study groups. Intravaginal Misoprostol is as effective a pre-induction cervical ripening agent as transcervical Foley catheters, with added advantages of shorter duration of cervical ripening, reduced oxytocin requirement for induction of labour and greater acceptability to patients. The incidence of caesarean sections, other labour complications and the foetal outcome were similar with both methods.