Induction With Foley OR Misoprostol (INFORM) Study (INFORM)

Induction of Labour in Pre-eclamptic Women: a Randomised Trial Comparing the Foley Balloon Catheter With Oral Misoprostol

Gynuity Health Projects, Government Dental College and Hospital, India, Daga Memorial Women's Hospital, Nagpur, India

Between 40,000 and 80,000 pregnant women die annually from pre-eclampsia and eclampsia. Magnesium sulphate and anti-hypertensive therapies can reduce the morbidity associated with pre-eclampsia. The only cure, however, comes with delivery. Prompt delivery of the baby, preferably by vaginal route, is vital in order to achieve good maternal and neonatal outcomes. Induction of labour is therefore a critical intervention in order to prevent morbidity to both mother and baby. Two low cost interventions - oral misoprostol tablets and transcervical Foley catheterization - are already used by some in low resource settings, but their relative risks and benefits are not known. These interventions could optimize the care pathway for women needing induction of labour. This is especially important in low resource settings where improvement is most needed and the potential to reduce the maternal and neonatal mortality and morbidity is the greatest. The ideal induction agent would result in a relatively short induction to delivery interval without risk to fetus and with low rates of emergency caesarean section. The induction to delivery interval is especially important in pre-eclampsia and eclampsia where the condition may deteriorate rapidly until delivery. Inductions with prostaglandins, including misoprostol, are sometimes associated with uterine hyperstimulation and consequent fetal hypoxia, whilst the effectiveness and safety of Foley catheter as an induction agent has been persistently questioned. This study will identify the risk, benefits and trade-offs in efficacy, safety, acceptability and cost of these two low cost induction methods.

This is a pragmatic, open-label, randomised control trial of two methods for labour induction among women with pre-eclampsia. Women requiring delivery for preeclampsia in two hospitals in Nagpur, India will be randomised to one of two treatment groups: transcervical Foley catheter or oral misoprostol tablets.

Group 2 will be induced using oral misoprostol tablets (25 mcg) every 2 hours for a maximum of 12 doses or until active labour commences. In primigravid women, if contractions have not commenced after 2 doses, the dosage may be increased to 50mcg every 2 hours. Once in labour (regular painful contractions with a cervical dilatation of at least 4cm) no more misoprostol will be used and artificial membrane rupture and/or oxytocin infusion will be used as clinically indicated. If labour has still not commenced after 24 hours, they will be deemed to have a 'failed induction' and the decision on further management will be made by the clinical team (their choice could include the use of repeat misoprostol, Foley catheter, dinoprostone, caesarean section or delay as deemed appropriate).

Group 1 will undergo induction using a transcervical Foley catheter (silicone, size 18F with 30ml balloon) which will remain until active labour starts, the Foley catheter falls out, or 12 hours have elapsed. If the Foley catheter falls out within 12h, membranes will be ruptured and/or oxytocin infusion started. If the Foley catheter does not fall out within 12h, it will be removed at 12h and oxytocin commenced with an artificial rupture of membrane when possible. If labour has still not commenced after 24 hours, they will be deemed to have a 'failed induction' and the decision on further management will be made by the clinical team (their choice could include the use of misoprostol, repeat Foley catheter, dinoprostone, caesarean section or delay as deemed appropriate).

Inclusion Criteria: Ongoing pregnancies with a live fetus in whom the decision has been made to induce vaginal delivery because of preeclampsia or uncontrolled hypertension. Women will be included irrespective of whether an intrapartum caesarean section on fetal grounds or would be considered or not. Women age ≥18 years Signed informed consent form Exclusion Criteria: • Women with previous caesarean sections Those unable to give informed consent Multiple pregnancy History of allergy to misoprostol Ruptured membranes Chorioamnionitis (by clinical diagnosis)

Mundle S, Bracken H, Khedikar V, Mulik J, Faragher B, Easterling T, Leigh S, Granby P, Haycox A, Turner MA, Alfirevic Z, Winikoff B, Weeks AD. Foley catheterisation versus oral misoprostol for induction of labour in hypertensive women in India (INFORM): a multicentre, open-label, randomised controlled trial. Lancet. 2017 Aug 12;390(10095):669-680. doi: 10.1016/S0140-6736(17)31367-3. Epub 2017 Jun 28.

Bracken H, Mundle S, Faragher B, Easterling T, Haycox A, Turner M, Alfirevic Z, Winikoff B, Weeks A. Induction of labour in pre-eclamptic women: a randomised trial comparing the Foley balloon catheter with oral misoprostol. BMC Pregnancy Childbirth. 2014 Sep 5;14:308. doi: 10.1186/1471-2393-14-308.