Induction of labour is a commonly practiced obstetric intervention designed to artificially initiate the process of effacement of the cervix, dilatation (cervical ripening), uterine contractions (often after augmentation with oxytocin) and eventually delivery of the baby. Common indications for induction of labour are post-term pregnancy, hypertensive disorders, diabetes in pregnancy, cholestasis, decreased physical activity of the fetus and prelabour rupture of membranes. Induction of labour with an unfavorable cervix is associated with prolonged labour compared to spontaneous onset of labour or induction of labour with a favorable cervix. Also an increase in instrumental deliveries and a higher rate of caesarean sections are seen [
1‐
3]. To increase the success of labour induction it is essential to achieve cervical ripening in women with an unfavorable cervix. Misoprostol has been widely studied as an agent for induction of labour. There are currently two Cochrane reviews focusing on the use of both oral and vaginal misoprostol [
4,
5]. These systematic reviews conclude that misoprostol is an effective and safe induction agent. Oral misoprostol is preferred to vaginal administration for as it shows lower rates of uterine hyperstimulation and adverse neonatal outcome [
4,
5]. Although not licensed for induction of labour, misoprostol is recommended by several guidelines. The British Royal College of Obstetricians and Gynaecologists (RCOG), as well as the World Health Organization (WHO), recommend the use of misoprostol tablets, based on cost-effectiveness. In the Dutch Society of Gynaecology and Obstetrics (NVOG) guideline for induction of labor, misoprostol is included and reported to be effective and safe [
6‐
8]. Another method for induction of labour is the transcervical Foley catheter. We recently showed (PROBAAT trial) that induction of labour with a Foley catheter is as effective as induction with intravaginal prostaglandin E2 gel, with fewer maternal and neonatal side-effects [
9]. The caesarean section rate was comparable and in the meta-analysis of three trials on the subject, the Foley catheter revealed a lower rate of hyperstimulation, resulting in fewer cases of asphyxia and less post partum haemorrhage. Consequently, the transcervical Foley catheter was recommended for induction of labour in women with an unfavorable cervix at term [
9]. The Foley catheter is reported to have similar success rates as induction of labour with misoprostol (vaginal and oral), and is associated with less uterine hyperstimulation with and without fetal heart rate (FHR) changes and a comparable caesarean section rate [
10‐
14]. As prostaglandins in general have been shown to cause an increased incidence of hyperstimulation, we expect a decreased blood flow of the placenta and consequently an increased the risk of asphyxia. In addition, hyperstimulation might lead to uterine muscle fatigue and thereby increase the risk for post partum haemorrhage. However, randomised controlled trials currently available are underpowered to investigate these estimators. In view of the scarce evidence on the subject, we propose a adequately-powered randomised controlled trial comparing induction of labour with a Foley catheter to induction of labour with oral misoprostol in women with an unfavorable cervix at term. In this trial the safety, cost-effectiveness and patient preference will be evaluated.