Planning birth at 41 weeks after one previous caesarean for fetal distress

Baseline. Overall, about 60–75% of women who attempt vaginal birth after caesarean succeed. For her specifically I would quote roughly 50–60%, and say so honestly rather than offering the population figure.

Factors in her favour

• The indication was fetal distress, which is not expected to recur; a non-recurring indication is a strong predictor of success.
• Single low transverse incision, no previous uterine surgery beyond that, two years since delivery.
• Spontaneous onset of labour would be the most favourable setting, and she is already 2 cm dilated.

Factors against

• No previous vaginal birth - the single strongest predictor of success is a prior vaginal delivery, which she has not had.
• BMI 33 kg/m², which lowers success and raises the chance of a big baby and slow labour.
• Post-term gestation and the likelihood that she will need induction, which lowers success further, to perhaps 50% with an unfavourable cervix.
• Estimated fetal weight 3.7 kg - acceptable, but above 4 kg success falls.

Uterine rupture. About 0.5% (roughly 2–7 per 1000) in spontaneous labour. Induction with oxytocin raises this to around 1–1.5%, and dinoprostone (PGE2) to a similar or slightly higher figure. Misoprostol is contraindicated. If rupture occurs the consequences are serious - perinatal death or hypoxic injury in a small but real proportion, maternal haemorrhage, hysterectomy and bladder injury - which is why the unit's ability to perform an immediate caesarean matters more than the absolute number.

The comparison she needs to hear: elective repeat caesarean has no rupture risk but carries its own risks of bleeding, infection, thromboembolism and placental problems in future pregnancies. Her indication and her wishes both support a trial of labour in a unit like this one, provided the plan and the escalation route are clear.

First, decide whether to induce at all. Expectant management to 41–42 weeks with twice-weekly assessment is defensible in some settings, but she is post-term, has a BMI of 33, and wants delivery; the stillbirth risk rises after 41 weeks, and she will need induction eventually. Induction now is reasonable. I would not wait beyond about 42 weeks.

Membrane sweep first, if she consents - it improves the chance of spontaneous labour and reduces the need for formal induction.

Mechanical method - Foley or Cook balloon. This is my first choice with a scarred uterus and a Bishop score of about 4. It ripens the cervix without prostaglandins and is not associated with a clear increase in rupture. It also avoids the systemic effects of dinoprostone. Place it, leave for 12–24 hours, then reassess.

Oxytocin once the cervix is favourable, with continuous fetal monitoring, one-to-one midwifery care and a low-dose titration. This is acceptable in a scarred uterus but raises rupture risk to around 1–1.5%, so use the lowest effective dose, avoid hyperstimulation and stop if the CTG becomes abnormal.

Dinoprostone (PGE2) is not absolutely contraindicated but roughly doubles or triples rupture risk compared with no prostaglandin, and I would use it only if mechanical methods fail and after consultant discussion.

Misoprostol must not be used - it is associated with a markedly increased rupture rate and is regarded as contraindicated in women with a previous caesarean.

If the cervix remains very unfavourable after a balloon and she is 41+5 or so, or if induction fails to establish labour, move to elective caesarean rather than stacking methods. Counsel her that induction here carries roughly a 50–60% success rate, that a failed induction ends in caesarean, and that this is not a failure of her choice.

Surveillance

• Continuous CTG from the onset of regular contractions, with the CTG reviewed at least hourly by a senior midwife and by the obstetrician at intervals; a scarred uterus does not tolerate a CTG that is only intermittently applied.
• One-to-one midwifery care in a room close to theatre, with intravenous access, group and save, and blood pressure and pulse recorded hourly.
• Oxytocin titrated to the lowest effective dose with contraction frequency documented; stop oxytocin for hyperstimulation or any CTG abnormality.
• Partogram with senior review at 4-hourly intervals; slow progress is not a reason to escalate oxytocin aggressively.
• Epidural is acceptable and does not mask rupture - the earliest and most reliable sign is an abnormal fetal heart pattern, not pain.

Warning signs of rupture

• Prolonged or terminal fetal bradycardia, or a sudden change from a normal trace.
• Loss of station of the presenting part on vaginal examination, or the head no longer palpable abdominally.
• Sudden, continuous severe abdominal pain, especially with a change in the character of contractions or contractions that stop.
• Vaginal bleeding, haematuria, maternal tachycardia, hypotension or shoulder-tip pain.

Action - this is a maternity emergency. Call for help and the consultant, abandon oxytocin, move to theatre immediately (do not wait for imaging), resuscitate with fluids and blood, and deliver by caesarean. Anticipate a fetus that may be severely anaemic, call the neonatal team, have blood products available, and be prepared for hysterectomy or uterine repair and for bladder injury. If the uterus is repaired and haemostasis is secure, document the scar site and advise on future pregnancy. This unit can perform the laparotomy; the 45-minute transfer is only for postoperative intensive care, which is an acceptable arrangement. Debrief the woman and her partner afterwards, and arrange a postnatal review with a clear plan for any future pregnancy.