Induction of labour with a foley catheter and misoprostol at term
Induction of labor is an intervention designed to artificially initiate the process of effacement of the cervix, dilatation, uterine contractions (often after augmentation with oxytocin) and eventually delivery of the baby. Induction of labor is a common procedure: twenty-two percent of all deliveries were induced in the Netherlands in 2007. A recent Dutch survey showed a wide variety of methods being used for induction of labor, intravaginal prostaglandin gel being used most frequently. A less frequently utilized method of ripening the uterine cervix is the transcervical Foley catheter. We recently showed that the use of a Foley catheter, in term women with an unfavorable cervix, resulted in equal vaginal delivery rates when compared to vaginal Prostaglandin E2 gel. And a meta-analysis showed lower rates of hyperstimulation, resulting in less asphyxia and postpartum haemorrhage.
Another prostaglandin that is frequently used for induction of labor is misoprostol (PGE1), which is recommended by the international federation of gynaecology and obstetrics (FIGO) for induction of labor. Misoprostol is used both vaginal and oral. The oral way seems to have lower rates of asphyxia and hyperstimulation. As direct comparisons between oral misoprostol and Foley catheter are lacking, we propose a randomized controlled trial comparing Foley catheter to oral misoprostol.
Objective: To assess in term pregnant women with an unfavorable cervix (Bishop score < 6, Appendix1) the effectiveness of induction of labor with a transcervical Foley catheter as compared to induction with oral misoprostol.
Study design: Multicentre Randomized Controlled Clinical Trial
Study population: Term pregnant women with an unfavorable cervix and an indication for induction of labor
Intervention: Induction of labor with a transcervical Foley catheter as compared to oral misoprostol.
This trial will be performed as a non-inferiority trial. Therefore, analysis will be done by per protocol analysis and by intention to treat, Our primary outcome will be a composite of asphyxia (pH¡Ü7.10 and/or 5 minute Apgar<7) and haemorrhage ¡Ý1000 cc post partum. With a power of 80% (1-¦Â) a one-sided 0.05 risk of type I error (¦Á) we calculated that we would require 1860 participants (930 per group) to demonstrate non-inferiority, i.e. that the absolute difference in the composite outcome was less than 5% more in the misoprostol group than in the Foley catheter group.