For parents, the sound of the baby's heartbeat on the monitor during labour is a source of reassurance. However, this monitor, known as a cardiotocograph (CTG), is a critical diagnostic tool used by medical staff to assess the baby's wellbeing.
The CTG produces a continuous graph designed to indicate if the baby is receiving sufficient oxygen or if they are becoming distressed. If the medical team fails to interpret this graph correctly, or if they do not act upon signs of distress, the baby can suffer from hypoxia (lack of oxygen). In a matter of minutes, this can lead to permanent brain injury, including hypoxic-ischaemic encephalopathy (HIE) and cerebral palsy.
At Michael Boylan LLP, we specialise in the forensic analysis of birth records. We scrutinise CTG traces minute-by-minute to determine the timeline of events in the delivery room.
What Is Cardiotocography (CTG)?
Cardiotocography, commonly referred to as electronic foetal monitoring, is the standard method used in Irish maternity hospitals to monitor a baby’s health during labour.
It typically involves two transducers (belts) placed on the mother’s abdomen:
- The Toko: This monitors the frequency and duration of the mother's contractions.
- The Cardio: This monitors the baby’s heart rate.
The machine produces a printed graph (or a digital trace) that shows how the baby’s heart rate reacts to contractions. In a normal labour, a baby’s heart rate varies naturally. When a baby is squeezed by a contraction, they might react, but they should recover quickly. If they do not recover, or if the heart rate flattens, it is a clinical sign that their oxygen reserves may be depleting.
Misinterpretation of CTG Traces
The failure to interpret a CTG trace correctly is a common issue in medical negligence litigation. The HSE National Clinical Guidelines classify CTG traces into three categories:
- Normal: No abnormal features. Labour can continue.
- Suspicious: Non-reassuring features are present. Increased surveillance is required.
- Pathological: The baby is likely compromised. Urgent delivery (Caesarean Section or instrumental delivery) is usually required.
Negligence often arises when a suspicious trace deteriorates into a pathological one, but the change is not recognised or acted upon by the midwifery or obstetric staff.
Vital Elements of the Trace
When we review files with independent experts, we analyse four specific elements:
A. Baseline Heart Rate
A normal foetal heart rate is between 110 and 160 beats per minute (bpm).
- Bradycardia: A heart rate below 110 bpm. If this drops suddenly and persists, it is an obstetric emergency.
- Tachycardia: A heart rate above 160 bpm. This can indicate maternal infection (such as Chorioamnionitis) or early foetal distress.
B. Variability
This is a critical indicator of brain health. A healthy baby’s heart rate is not static; it fluctuates by 5-25 beats.
- Reduced Variability: If the trace becomes a smooth, flat line for more than 40-90 minutes, it suggests the baby’s nervous system is depressed, possibly due to hypoxia or acidosis.
C. Accelerations
These are temporary increases in the heart rate, usually occurring when the baby moves. They are generally a sign of a healthy, reactive baby.
D. Decelerations
A deceleration is a drop in the heart rate. The timing of the drop relative to the contraction is significant.
- Early Decelerations: The heart rate drops at the same time as the contraction (often due to head compression). This is usually normal.
- Late Decelerations: The heart rate drops after the contraction has finished. This indicates the placenta is not delivering enough oxygen, and the baby is struggling to recover.
- Variable Decelerations: Sharp drops that resemble a “V” shape, suggesting umbilical cord compression.
Syntocinon (Oxytocin) and Hyperstimulation
A significant number of birth injury cases involve the administration of syntocinon (synthetic oxytocin). This drug is given via an IV drip to induce or accelerate labour by making the uterus contract more frequently and strongly.
While effective, syntocinon carries a risk of hyperstimulation. Hyperstimulation happens when the uterus contracts too often (typically more than 5 times in 10 minutes), and there is insufficient resting time between contractions. The placenta requires this resting time to refill with oxygenated blood for the baby. Without it, the baby’s oxygen supply is compromised.
If a CTG trace shows signs of distress (such as late decelerations), clinical guidelines state that the syntocinon infusion should be reduced or stopped immediately. We investigate whether the medication was continued or increased despite evidence that the baby was unable to tolerate the frequency of contractions.
Failure to Perform Foetal Blood Sampling (FBS)
When a CTG trace is classified as suspicious but not yet pathological, guidelines often recommend a secondary test called foetal blood sampling (FBS).
This procedure involves taking a small sample of blood from the baby’s scalp during labour to test for pH levels (acidosis) and lactate.
- Normal pH: The baby is oxygenated.
- Low pH (Acidic): The baby is hypoxic and requires immediate delivery.
We investigate cases where the CTG was abnormal, but the medical team failed to perform an FBS to confirm the baby's condition, relying instead on visual interpretation alone. This can lead to a delay in diagnosis and delivery.
The Consequences of Misinterpreting CTG Traces: Hypoxic-Ischaemic Encephalopathy (HIE)
When a CTG trace is misinterpreted, the most serious risk is that the baby is left in a low-oxygen environment for too long. This leads to a condition called Hypoxic-Ischaemic Encephalopathy (HIE).
HIE is a brain injury caused by a combination of oxygen deprivation (hypoxia) and restricted blood flow (ischemia). During labour, the placenta acts as the baby’s lung. Every contraction temporarily squeezes the blood vessels, reducing blood flow. A healthy baby can cope with this stress, but if the contractions are too strong or the umbilical cord is compressed, the baby’s oxygen supply drops to dangerous levels.
The CTG monitor is designed to alert the medical team to this specific danger. If the staff miss these warnings and allow the labour to continue, the baby’s brain begins to starve of oxygen. The timing is crucial; a delay of even ten or fifteen minutes in delivering the baby can make the difference between a full recovery and a permanent disability.
Therapeutic Hypothermia as an Indicator of Injury
The severity of HIE is often immediately apparent at birth. If a baby is born in poor condition,pale, floppy, or not breathing,they are often transferred to the Neonatal Intensive Care Unit (NICU) for therapeutic hypothermia.
This treatment, commonly known as “cooling,” involves lowering the baby’s body temperature for 72 hours. This slows down the brain's metabolism to limit the spread of damage. In a legal context, the fact that a baby required cooling is a significant indicator. It confirms that a moderate to severe hypoxic event occurred, and our investigation will focus on whether the CTG trace showed evidence of this distress before the birth took place.
The Investigation Process
At Michael Boylan LLP, we employ a forensic approach to investigating CTG-related claims.
Step 1: Retrieval of Records
We obtain the complete medical file, including the actual copies of the CTG traces (paper or digital export). In modern maternity units, these are often stored on electronic systems. We ensure these digital audit trails are preserved.
Step 2: Independent Expert Review
We instruct specialist consultant obstetricians and midwives to audit the records. We typically use experts based in the United Kingdom. This ensures total independence and avoids potential conflicts of interest within the Irish medical community. The expert performs a review to determine what a competent practitioner should have identified at the time.
Step 3: Causation Analysis
Establishing a breach of duty is only the first step. We must also prove that the delay caused the injury. We work with paediatric neurologists and neuroradiologists who analyse MRI scans to determine the timing and nature of the brain injury.
Frequently Asked Questions
Can I claim if the doctor said the trace was “difficult to read”?
Yes. If a trace is unreadable due to maternal BMI or foetal movement, the medical team has a duty to use alternative monitoring methods (such as a foetal scalp electrode) or to perform an ultrasound. Leaving a trace unmonitored for extended periods is not acceptable.
What is the time limit for a CTG negligence claim?
The Statute of Limitations is generally two years. However, for a child injured at birth, the limitation period does not begin until they turn 18. This means a claimant generally has until their 20th birthday to initiate proceedings. We strongly advise investigating earlier to preserve evidence.
My baby required cooling therapy. Does this indicate negligence?
While therapeutic hypothermia (cooling) does not automatically prove negligence, it confirms a significant injury occurred. An investigation is required to determine if the hypoxic event could have been avoided or shortened.
Do I need the original graph paper?
We handle the retrieval of all evidence. During the discovery process, the hospital is legally required to provide the best quality copies of the trace.
Contact Michael Boylan LLP
If you have concerns about the monitoring of your labour or the condition in which your baby was born, we can provide the clarity you require. At Michael Boylan LLP, we specialise in the forensic audit of maternity records to determine whether clinical standards were upheld or if critical warning signs were overlooked.
Determining the truth behind a birth injury is the first step in ensuring your child has access to the specialist therapies and lifelong security they may need. To discuss your situation in a confidential and professional environment, please contact our offices.
*In contentious business, a solicitor may not calculate fees or other charges as a percentage or proportion of any award or settlement.
