Trial of Labour After Two Caesareans: Balancing Risks
A 32-year-old woman, G4P2, presents at 39 weeks with spontaneous labour. Her obstetric history includes two previous caesarean deliveries: the first for failure to progress at 8 cm, and the second an elective repeat. She has had no prior vaginal delivery. She is 160 cm tall, BMI 31, and her current pregnancy has been uncomplicated. Ultrasound shows a single fetus in cephalic presentation, estimated fetal weight 3.6 kg. She strongly desires a vaginal birth and declines immediate caesarean. On admission, cervical dilatation is 4 cm, effaced 80%, station -2, and contractions are every 5 minutes. The unit has 24-hour theatre and blood bank facilities, and continuous fetal monitoring is available. The consultant is on site.
1. What are the key risks and benefits of attempting a trial of labour after two caesareans (TOLAC-2) versus elective repeat caesarean delivery (ERCD) in this woman? How would you counsel her?
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Risks of TOLAC-2: The main concern is uterine rupture. With two prior caesareans, the risk of rupture is higher than with one, though still relatively low (approximately 0.5–1.5% in contemporary series, compared with 0.5–0.7% for one prior). Rupture can cause serious maternal morbidity (haemorrhage, hysterectomy, bladder injury) and perinatal morbidity/mortality (hypoxic-ischaemic encephalopathy, death). The risk of failed TOLAC is higher than with one prior scar (success rates around 60–70% vs 70–75%), especially with no prior vaginal birth. Failed TOLAC leads to unplanned caesarean with increased maternal morbidity.
Benefits of TOLAC-2: Avoidance of abdominal surgery, shorter recovery, lower risk of thromboembolism, infection, and future placental abnormalities (accreta, praevia) in subsequent pregnancies. If successful, lower risk of respiratory morbidity for the baby.
Risks of ERCD: Surgical risks (infection, haemorrhage, thromboembolism, injury), longer recovery, increased risk of placenta accreta spectrum and caesarean hysterectomy in future pregnancies, and small risk of fetal laceration. ERCD avoids labour and rupture risk.
Counselling: Use shared decision-making. Explain that TOLAC-2 is a reasonable option in a well-resourced setting with continuous monitoring and immediate theatre access. Discuss that her chance of success is moderate (no prior vaginal birth, BMI >30, fetal weight >3.5 kg reduce success). Emphasise that if she opts for TOLAC, continuous fetal monitoring and immediate availability of theatre and blood products are mandatory, and that induction or augmentation should be cautious (avoid high-dose oxytocin; prostaglandins are contraindicated). Document the discussion. If she declines ERCD, support her choice with a clear plan for intrapartum monitoring and escalation.
2. During labour, 2 hours after admission, the midwife reports a sudden fetal heart rate deceleration to 80 bpm lasting 3 minutes, with loss of variability. The mother complains of constant abdominal pain and vaginal bleeding is noted. What is your immediate management?
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This is a suspected uterine rupture. Immediate actions:
- Call for help: Activate emergency team (obstetrician, anaesthetist, theatre staff, neonatal team, blood bank).
- Maternal resuscitation: Left lateral tilt, IV access with two large-bore cannulae, oxygen, crystalloid, cross-match blood.
- Fetal monitoring: Do not delay for further monitoring; the fetal heart rate is non-reassuring and suggestive of rupture.
- Immediate caesarean: Proceed to emergency caesarean (category 1) without delay. Inform theatre and anaesthetist.
- Prepare for possible hysterectomy and blood transfusion: Consent for hysterectomy if needed; ensure blood products available.
- Neonatal team: Alert paediatricians for possible neonatal resuscitation.
- Documentation: Record events and timing.
Do not attempt vaginal delivery or wait for ultrasound confirmation. Uterine rupture is a clinical diagnosis; delay increases perinatal mortality and maternal morbidity. After delivery, inspect the uterus, repair if possible, and consider hysterectomy if extensive. Provide antibiotics and thromboprophylaxis postoperatively. Debrief the patient and family.