Failed Induction

Failed induction is failure to start labour or to reach the active phase (cervix 6 cm or more dilated) after a full course of cervical ripening and at least 12 to 18 hours of oxytocin after membranes have ruptured. It results from an unripe cervix, wrong dates, malposition, disproportion or inadequate contractions. It matters because it often leads to caesarean section, and the right next step depends on the indication and the condition of mother and baby.

• Risk factors: first pregnancy, Bishop score below 6, body mass index above 30 kg/m2, maternal age above 35 years, short stature, large baby.
• Prolonged waiting with ruptured membranes raises infection risk.
• The original reason for induction guides how long to wait.

Women have had ripening and oxytocin without entering active labour, with a closed or slightly open cervix and irregular or weak contractions. They are often tired and anxious.

• Cervix less than 6 cm dilated after hours of oxytocin.
• Fever or fetal tachycardia if membranes have been ruptured for long.
• Differential diagnosis: prolonged latent phase, inadequate contractions, cephalopelvic disproportion, occiput posterior position, chorioamnionitis, wrong gestation.
• Complications: chorioamnionitis, exhaustion, tachysystole, fetal distress, uterine rupture in a scarred uterus, caesarean section, postpartum haemorrhage, neonatal sepsis.

The diagnosis is made on the partograph after reviewing the indication and the condition of mother and baby.

• Cervical dilatation, effacement, station and Bishop score before and after each method; duration of membrane rupture and oxytocin dose reached.
• Cardiotocography; maternal temperature, pulse, hydration, urine ketones.
• Ultrasound for position, estimated fetal weight, liquor volume and umbilical artery Doppler if growth restriction was the indication.
• Check gestation and whether the original indication still requires birth.

The principle is to review the need for birth, then continue, repeat ripening after rest, or deliver by caesarean section.

• Supportive: explain the options; rest, food and fluids for 12 to 24 hours when membranes are intact and mother and baby are well; Ringer's lactate 1 litre IV over 2 hours; continuous cardiotocography on oxytocin; senior review.
• Pharmacological: misoprostol 25 micrograms vaginal 6-hourly (maximum 4 doses) in an unscarred uterus; oxytocin 10 IU in 1 litre Ringer's lactate (10 mU/mL) started at 12 mL per hour (2 mU/minute) and doubled every 30 minutes to a maximum of 192 mL per hour (32 mU/minute) for up to 24 hours when membranes are ruptured and there is no infection; benzylpenicillin 5 million units IV then 2.5 million units 4-hourly for rupture of 18 hours or more; ampicillin 2 g IV 6-hourly plus gentamicin 5 mg/kg IV once daily for chorioamnionitis; cefazolin 2 g IV before caesarean section; oxytocin 10 IU IM after birth, then 20 IU in 1 litre at 125 mL per hour for 4 hours.
• Procedures: Foley catheter with a 30 mL balloon for ripening; amniotomy when the head is engaged; caesarean section for fetal compromise, chorioamnionitis, a strong indication to deliver, no progress after a full second course, or disproportion.
• Special groups: a uterine scar avoids misoprostol and uses a Foley catheter or oxytocin with senior review; grand multiparity uses lower oxytocin rates with close monitoring; women with growth restriction or abnormal Doppler go to caesarean section sooner.
• Red flags: fever above 38 degrees Celsius, tachysystole, abnormal fetal heart rate, scar pain, bleeding, ruptured membranes for 18 hours or more.
• Follow-up: reassess every 2 to 4 hours; maternal temperature 4-hourly; newborn observation for 24 hours with a sepsis screen if rupture was prolonged; review at 6 weeks.