CTG in Labour: What Parents Need to Know
When you imagine your baby’s birth, you probably picture the moment you finally meet them, not wires, straps, or machines. But for many families, a CTG (cardiotocography) monitor is part of the labour room setup. So what is it, why is it used, and, most importantly, how can you make informed decisions about it?
What exactly is a CTG?
A CTG is a machine that tracks your baby’s heartbeat alongside your contractions. It involves two belts around your belly: one to measure the baby’s heart rate, the other to record your uterine activity. The goal is to see how your baby is coping with labour.
Sounds straightforward, right? But the story of CTG is more complex, and understanding it can help you feel more confident if it comes up in your birth.
CTG was first introduced in the 1960s and 70s, at a time when new technology in hospitals was booming. It promised reassurance: a machine that could see inside the womb and warn of danger. Hospitals adopted it quickly, sometimes more because of sales pitches and the cultural push toward “high-tech medicine” than solid evidence.
The problem? Early studies found that continuous CTG monitoring didn’t actually reduce the rates of cerebral palsy or improve overall outcomes for babies. What it did increase was interventions: inductions, forceps, ventouse, and caesarean births.
How reliable is CTG? Let’s look at the evidence
While CTG is widely used, research over the past decades has highlighted both its strengths and limitations. Here’s a summary:
Continuous vs. intermittent monitoring: A Cochrane review (2017) analyzed dozens of trials and found that continuous CTG monitoring for low-risk pregnancies does not reduce the risk of perinatal death or cerebral palsy compared to intermittent auscultation (listening with a handheld Doppler). However, it does increase the likelihood of interventions like C-sections and instrumental deliveries.
False positives are common: CTG is highly sensitive, meaning it often flags changes in heart rate patterns. But sensitivity comes at a cost. Many alerts are false positives. A study found that in low-risk labours, up to 60% of abnormal CTG readings led to intervention when the baby was actually fine. This can add stress and unnecessary procedures.
Interpretation matters: Human interpretation of CTG traces varies widely. One hospital study reported that two clinicians could read the same trace and disagree up to 50% of the time.
Context is key: CTG is most valuable in high-risk situations: reduced fetal movements, preeclampsia, growth restriction, or complicated labours. In these cases, research supports that continuous monitoring can detect genuine fetal distress and guide timely interventions, potentially saving lives.
Is CTG always accurate?
Here’s where it gets tricky. CTG machines are very sensitive. They pick up every dip, rise, and wiggle in the heart rate trace. But not every change means a baby is in trouble. In fact, CTGs are notorious for false positives, suggesting distress when the baby is actually fine.
Research shows that while CTG is good at detecting if a baby might be struggling, it’s not so good at telling which babies are genuinely at risk. That means some families experience unnecessary worry and interventions.
So why is CTG still used?
Great question! Guidelines today (like those from NICE in the UK, ACOG in the US, and FIGO internationally) recommend CTG in specific circumstances, for example, if there are known risk factors or complications. For many low-risk labours, intermittent listening with a handheld Doppler is just as safe, and it allows for more freedom of movement.
That said, CTG can be very reassuring in higher-risk situations and sometimes provides crucial information. It’s about balance, and it’s about context.
What does this mean for you?
If CTG monitoring comes up in your birth, here are some things to keep in mind:
Ask why: Is it routine, or is there a clear reason?
Know your options: Intermittent monitoring is often possible in low-risk situations.
Movement matters: Even with a CTG, you can often stand, kneel, or lean forward. Don’t feel glued to the bed.
Trust yourself: Machines don’t replace your voice, your instincts, or your choices.
The bigger picture
CTG is not the enemy, but it isn’t perfect either. Like so many tools in maternity care, it can be helpful when used wisely, but it can also lead to over-intervention if used without thought. The most important thing is that you understand what’s happening and feel empowered to be part of the decision-making.
Your birth, your baby, your body. You deserve to feel confident in every part of that journey.
