When a woman who has previously had a caesarean section is advised to have her next baby by vaginal (VBAC) delivery, she may be at risk of uterine rupture.
RCOG guidelines require maternity teams to follow specific safety measures when planning or carrying out ‘vaginal birth after caesarean section’ or VBAC for the safety of the mother and baby. This includes careful counselling, decision making, planning, resourcing and management of labour.
Where a woman undergoing VBAC is incorrectly counselled or advised, or her labour is incorrectly managed, she may suffer life-threatening injury from uterine rupture and severe brain injury or the death of her baby.
What is uterine rupture in childbirth?
Rupture (tearing) of the mother’s uterus (womb) in childbirth is a life-threatening emergency for both the mother and the baby. When the womb ruptures or the scar from a previous caesarean section breaks open, the mother suffers severe bleeding and the unborn baby is deprived of oxygen, causing brain injury and severe disability or death.
The mother’s life is also at risk from severe uterine haemorrhaging (bleeding). She may need a life-saving hysterectomy, preventing her from having further children, or the injury to her uterus may affect her future pregnancies.
What are the risks of VBAC compared with a planned repeat caesarean section (ERCS)?
Where delivery takes place at or after 39 weeks of pregnancy, in circumstances which are suitable for VBAC:
- Planned VBAC has a 1 in 200 (0.5%) risk of uterine rupture, compared with 2 in 10,000 (0.02%) where the mother’s uterus was previously unscarred. The risk increases when VBAC delivery is induced or labour is augmented (boosted) with syntocinon;
- The success rate for planned VBAC is 72-75% but increases if the mother has had a previous vaginal or successful VBAC delivery. If VBAC delivery is successful, it has fewer complications than ERCS;
- Unsuccessful VBAC resulting in emergency caesarean section has the greatest risk of poor outcome;
- The risk of unsuccessful VBAC and caesarean section increases if VBAC labour is induced or augmented with syntocinon.
Who is suitable for VBAC?
The RCOG guidelines for VBAC list the circumstances most suited to VBAC:
- singleton pregnancy (i.e. expecting one baby);
- cephalic presentation (baby is head down);
- pregnancy at 37 weeks or more;
- single previous LSCS (lower segment caesarean section - scar across the lower part of the abdomen).
A successful VBAC delivery is more likely where:
- mother is taller;
- mother is younger than 40;
- mother has a BMI below 30;
- labour starts spontaneously (not induced) before 40 weeks;
- baby is in vertex presentation;
- baby’s birthweight is below 4kg.
The risk of uterine rupture during VBAC increases with the mother’s age and the baby’s gestation and size. The risk is also higher for mothers whose last delivery took place less than 12 months before.
Who can’t have a planned VBAC delivery?
Planned VBAC is contraindicated and should not take place where:
- there is a history of uterine rupture;
- mother has a previous classical caesarean scar (scar goes vertically up the middle of the abdomen);
- there is placenta praevia (i.e. the placenta’s position would obstruct a vaginal delivery);
- the mother has a history of surgery on her uterus.
Who decides whether the delivery will be by VBAC or ERCS?
The choice of delivery mode must be agreed by a senior obstetrician and the mother, based on her personal risk factors, before the planned date of delivery. Before the decision is made, the mother must be counselled by the senior doctor about the risks of VBAC and the circumstances in which a trial of VBAC would be abandoned and caesarean section needed.
All antenatal counselling must be documented in the medical records. If a repeat caesarean section (ERCS) is planned, a plan must be agreed for what happens if the mother goes into labour early. This back up plan must be written in the records.
What additional safety measures should be in place during VBAC delivery?
VBAC labour must take place in a delivery suite equipped for continuous intrapartum (childbirth) care and monitoring, with facilities for immediate caesarean delivery and advanced neonatal resuscitation.
The fetal heart must be continuously monitored electronically from the start of regular contractions throughout the labour and delivery. This helps maternity staff to recognise signs of deterioration in the mother or unborn baby early, and to notice if labour is obstructed or the mother’s previous scar is breaking down. The mother’s condition and progress of labour must be regularly monitored by one-to-one care.
What causes hyperstimulation of the uterus?
Syntocinon (a synthetic oxytocin hormone drug) or other drugs are sometimes used to start or augment (speed up or boost) labour. Syntocinon can cause contractions to be too close together and too strong. This is known as hyperstimulation of the mother’s uterus. Hyperstimulation is dangerous because it can lead to uterine rupture.
When syntocinon is used in labour, the fetal heartrate must be continuously monitored electronically from the start of regular contractions throughout the labour, so that signs of potential injury to the mother or unborn baby are detected as early as possible.
The midwife must also monitor the frequency and strength of the mother’s contractions and adjust the dosage or stop the drugs if signs of hyperstimulation occur. Even where uterine rupture does not occur, hyperstimulation can cause serious brain injury to the unborn baby.
What are the clinical signs of uterine rupture in labour?
The three classic signs of uterine rupture are pain, vaginal bleeding and fetal heart-rate abnormalities. However, in nearly half of all cases the uterine scar from the previous caesarean section or other surgery breaks down without any maternal symptoms.
It is often only diagnosed later when the mother is undergoing an emergency caesarean section after monitoring reveals fetal distress requiring urgent delivery of the baby.
Signs in labour which are associated with uterine rupture include:
- abnormal CTG (most common sign);
- severe abdominal pain, particularly if the pain continues between contractions;
- sudden scar tenderness;
- abnormal vaginal bleeding;
- haematuria (blood in the urine);
- previously efficient contractions stop;
- maternal tachycardia (elevated heart rate), hypotension (low blood pressure), fainting or shock;
- change in abdominal shape and the fetal heartrate is not detected at the previous transducer site;
- the fetus is no longer presenting properly.
Suspected rupture of the uterine scar is an emergency requiring urgent caesarean section and neonatal resuscitation. Uterine rupture restricts the unborn baby’s oxygen supply and quickly leads to permanent brain damage or death.
Boyes Turner’s recent cases
Boyes Turner’s cerebral palsy and birth injury solicitors are highly experienced in obtaining compensation settlements for clients who have been seriously injured as a result of negligent VBAC, uterine rupture or hyperstimulation.
Our recent cases include:
- A very substantial settlement for a boy with cerebral palsy after CTG monitoring was incorrectly stopped despite fetal heart-rate abnormalities and maternal signs of placental abruption. The mother deteriorated whilst left unattended in labour. Uterine rupture was diagnosed during the emergency caesarean section which was carried out much later after the fetal heart-rate could not be detected.
- Settlement for a woman who suffered uterine rupture during a VBAC delivery for which she had not given informed consent. After haemorrhage and emergency surgery incorrect anti-coagulant therapy led to cardiac arrest and neurological damage which has left her in an unconscious, minimally responsive, PVS-like state. The baby suffered severe brain injuries during the mismanaged labour and died two years later.
- An admission of liability (with damages to be assessed) for a boy with cerebral palsy caused by hypoxic brain injury from excessive use of Syntocinon and hyperstimulation during his mother’s labour.
- A very substantial settlement for a child with cerebral palsy whose brain was damaged as a result of negligent syntocinon use, uterine rupture and delays during a mismanaged VBAC delivery.
- £16 million settlement for a child with cerebral palsy after fetal distress in labour was compounded by negligent syntocinon use and delays in delivery.
If you or your baby have suffered severe injury as a result of medical negligence at birth, contact one of our specialist solicitors by email email@example.com.