Induction of labour in pre-eclamptic women: a randomised trial comparing balloon catheter with oral misoprostol.

High blood pressure in pregnancy (or preeclampsia) is a major cause of death worldwide, killing up to 80,000 pregnant women annually. For women with preeclampsia currently available therapies improve the outcome of the illness, but the final cure only comes with delivery of the baby. Prompt delivery, preferably by the vaginal route rather than by caesarean section, is therefore vital to achieve good maternal and neonatal outcomes. There are various methods available to start the woman?s labour, and it is crucial that the method used is both effective and safe for mother and baby. This is especially important in low resource settings where the underlying illness is often severe and there are few facilities for monitoring the mother and baby. The World Health Organisation currently recommends two low cost options ? oral misoprostol (OM) tablets and transcervical Foley catheterisation (TFC). Whilst in the former method a tablet is swallowed every two hours, in the latter a thin rubber (?Foley?) catheter is threaded through the neck of the womb and held in place with a small inflated balloon at its tip. Although OM has been widely studied, it is infrequently used in India. Furthermore, there is comparatively little research on the TFC and the two methods have never been directly compared despite their great promise. Current evidence suggests that OM may be faster but sometimes ?overcontract? the uterus, whilst TFC may be slower but safer.

We propose a study to be conducted in two large government hospitals in Nagpur, India. 800 women with preeclampsia will be randomly allocated to use OM (25mcg tablets 2hrly) or TFC (size 18F with a 50ml balloon for 12 hours) for their induction. The main outcome is the attainment of vaginal delivery within 24 hours, and a variety of other measures of maternal and neonatal morbidity including cost effectiveness will also be collected. Currently 15% of mothers with preeclampsia suffer stillbirths in this setting ? this trial will also examine whether the use of the balloon catheter can reduce this.

Recruitment rates in a recent study of preeclamptic women using the same team and site demonstrate that 800 women can be recruited in 2 years. The study will be managed on a daily basis by the successful team of Dr Mundle in GMC Nagpur and Gynuity Health Projects, one of the most successful low-resource setting clinical trial specialists in the world.

Up to 80,000 pregnant women die annually from pre-eclampsia and eclampsia ? many of them in India where there are more maternal deaths than any other country. Current therapies reduce the morbidity associated with pre-eclampsia but the final cure only comes with delivery. Prompt delivery of the baby, preferably by the vaginal route following labour induction, is vital to achieve good maternal and neonatal outcomes. The need for an effective and safe induction method is especially important in low resource settings where the underlying illness is often severe and there are minimal facilities for monitoring of mother and baby. The WHO currently recommends one of two different interventions for low resource settings ? oral misoprostol (OM) and transcervical Foley catheterisation (TFC). Although OM has been widely studied, there is comparatively little research on the TCF. Neither are widely used and the two methods have never been directly compared. Current evidence suggests that OM may be faster but with more uterine hyperstimulation, whilst TFC may be slower but safer.

We propose an open label randomised trial of OM (25mcg tablets 2hrly) versus TFC (18F with 50ml balloon for 12 hours). The study will be conducted in two large government hospitals in Nagpur, India and will recruit women with preeclampsia who require induction of labour. Following informed consent, labour induction will be carried out using the selected method, followed by artificial membrane rupture and oxytocin infusion as required. The primary outcome is the attainment of vaginal delivery within 24 hours which is expected in 62% of women in the OM group. To detect an absolute reduction of 10% in this rate (i.e. 62% to 52%) with 80% power (two-sided a =0.05) we will require a sample of 768 women. This number will also have 80% power to detect a reduction in stillbirth rate from 15% (data from a recent study in the same site) to 8.5%. The secondary outcomes will include measures of maternal and neonatal morbidity up to the time of hospital discharge as well as a detailed economic evaluation.

Recruitment rates in a recent study of pre-eclamptic women using the same team and site demonstrate that 800 women can be recruited in 2 years. The study will be managed on a daily basis by the successful team of Dr Mundle in GMC Nagpur and Gynuity Health Projects, one of the most successful low-resource setting clinical trial specialists in the world.