Mifepristone versus placebo to increase the rate of spontaneous labour in people with a prior caesarean: A double blind randomised controlled trial

INTERVENTION: Mifepristone, 200mg, orally, given as a single dose, encapsulated in opaque capsule cover, administered to participants who are at least 36 weeks 6 days gestational age, under direct supervision by research staff. CONDITION: Reproductive Health and Childbirth ‐ Other reproductive health and childbirth disorders vaginal birth after caesarean;labour; ; vaginal birth after caesarean ; labour PRIMARY OUTCOME: Spontaneous labour onset; ; This is defined as regular uterine contractions causing cervical change (with a minimum cervical dilation of 3 centimetres). Confirmed with cardiotocography or uterine palpation and a cervical examination by either a midwife or doctor. Confirmed via electronic medical record review. [ From drug ingestion to 48 hours post drug ingestion] SECONDARY OUTCOME: Abnormal cord blood lactate (greater than or equal to 4.0), defined as the highest value obtained (if multiple tests performed). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Abnormal cord blood pH (less than or equal to 7.10), defined as the lowest value obtained (if multiple tests performed) ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Admission to ICU or equivalent ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Adverse neonatal outcome, defined as admission to the neonatal intensive care unit, neonatal seizures, neonatal encephalopathy. ; ; Confirmed via electronic medical record review. [ From birth to 28 days from birth] Antepartum haemorrhage (defined as greater than or equal to 500mL) ; ; Confirmed via electronic medical record review. [ Prior to established labour (from drug ingestion to 30 days from drug ingestion).] Apgar scores at 1, 5, 10 minutes (if applicable) ; ; Confirmed via electronic medical record review. [ At 1, 5 and 10 minutes after birth] Average time from drug administration to onset of labour ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Average time from drug administration to vaginal birth ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Average time from onset of labour to vaginal birth ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Caesarean birth for any indication (overall rate) ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Caesarean birth for fetal heart rate abnormalities (as identified from operative report). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Cesarean birth for labour dystocia (as identified from operative report). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Cord prolapse ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Cost effectiveness (calculated by assessing cost of induction, caesarean and delivery unit stays in days for each participant). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Cost effectiveness for mother‐baby dyad (calculated by maternal length of stay during birth admission and any readmission within 7 days of birth, neonatal length of stay during birth admission, use of operating theatre). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 37 days from drug ingestion] Fetal heart rate abnormalities (as documented in the patient chart). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Fetal heart rate abnormalities resulting in fetal scalp lactate sampling (as determined from review of the patient chart) ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Fetal heart rate abnormalities resulting in instrumental vaginal birth (as documented in the patient chart) ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Induction of labour with amniotomy as initial approach. ; ; Confirmed via electronic medical record review. [ From drug ingestion until 30 days from drug ingestion] Induction of labour with an intracervical catheter as initial approach. ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Induction of labour with exogenous contractile agent (oxytocin, as initial approach) ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Induction of labour with exogenous contractile agent (oxytocin, as sequential approach). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Induction of labour. ; ; Performed in a hospital setting by either a midwife or a doctor. Confirmed via electronic medical record review. [ From drug ingestion until 30 days from drug ingestion] Infant born with a 5 minute Apgar score less than 7 ; ; Confirmed via electronic medical record review. [ Measure completed at 5 minutes of age. ] Intrapartum haemorrhage (defined as greater than or equal to 500mL). ; ; Confirmed via electronic medical record review. [ During established labour (from drug ingestion to 30 days from drug ingestion).] Live birth ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Maternal satisfaction, based on survey data collected after birth ; ; Survey created for this study. [ The survey will be administered once, timing from one week after the birth until 180 days post birth. ] Neonatal death (early) within 28 days[ From birth to 28 days from birth] Non‐cephalic presentation (breech, transverse, oblique) ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Performance of 'stretch and sweep' or 'membrane stripping' ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Postpartum haemorrhage (within 24 hours of birth, defined as greater than or equal to 500mL), ; ; Confirmed via electronic medical record review. [ Within 24 hours of birth (from drug ingestion to 30 days from drug ingestion).] Rupture of membranes at term prior to labour where a prelabour caesarean is performed (rather than induction with oxytocin infusion), measured until birth. ; ; Confirmed by physical examination by a midwife or doctor. Confirmed via electronic medical record review. [ From drug ingestion until 30 days from drug ingestion] Rupture of membranes at term prior to labour where induction of labour is performed, measured until birth. ; ; Confirmed by physical examination by a midwife or doctor. Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Rupture of membranes at term prior to labour, ; ; Confirmed by physical examination by a midwife or doctor. Confirmed via electronic medical record review. [ From drug ingestion to 48 hours post drug ingestion] Time to artificial rupture of membranes ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Use of epidural anaesthesia, time placed ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Use of intravenous narcotic analgesia ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Uterine hyperstimulation (defined as greater than 5 contractions per 10 minute period for at least 20 minutes with concurrent abnormal fetal heart rate pattern). Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion ; ; ] Uterine rupture ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] Uterine tachysystole (defined as greater than 5 contractions per 10 minute period for at least 20 minutes). ; ; Confirmed via electronic medical record review. [ From drug ingestion to 30 days from drug ingestion] INCLUSION CRITERIA: Pregnant people with a live singleton and cephalic presentation History of one or two prior caesarean births Intention to deliver vaginally Intact membranes Normal CTG prior to randomisation Maternal age 16‐50 years Gestational age between 36 6/7 and 41 6/7 weeks gestation