Cardiotocography (CTG)

A CTG (cardiotocography) is a monitoring test that records a fetus’s heart rate and uterine contractions. Used during pregnancy and labour, it detects patterns—accelerations, decelerations and baseline rate—to assess fetal wellbeing and identify possible distress. Readings guide obstetric management (observation, interventions or delivery). It’s an obstetric fetal-monitoring tool, not a diagnostic test for adult cardiac disease.

Normal CTG shows a baseline fetal heart rate of 110–160 bpm, moderate variability (~5–25 bpm), and regular accelerations (term: ≥15 bpm lasting ≥15 seconds). It should have no recurrent late decelerations and only occasional brief variable decelerations. This pattern suggests adequate fetal oxygenation and response to movements and contractions; abnormal features warrant further assessment.

Cardiotocography (CTG) assesses four key features: baseline fetal heart rate (normal 110–160 bpm), variability (short-term fluctuations indicating fetal well-being), accelerations (transient rises suggesting fetal health), and decelerations (drops classified as early, variable, or late indicating possible fetal compromise). Prompt intervention may follow if abnormalities are detected.

Yes—CTG is generally safe. External CTG (Doppler and toco) is non‑invasive and used to monitor fetal heart rate and contractions. Internal monitoring (scalp electrode or intrauterine catheter) is invasive and used only when indicated; it carries small risks such as infection or bleeding. CTG can produce false positives and increase interventions, so its use is tailored to clinical need.

A CTG monitors fetal heart rate and uterine contractions to detect signs of fetal distress—abnormal heart-rate patterns (bradycardia, tachycardia, late or variable decelerations) that may indicate hypoxia. It’s useful during labour and high‑risk pregnancies but is a screening, not definitive, test: it can give false positives/negatives and cannot diagnose structural problems. Abnormal traces prompt further assessment.

Cardiotocography (CTG) is usually not painful. External CTG uses elastic belts on the abdomen and may feel uncomfortable or restrict movement, but isn’t painful and doesn’t harm the baby. Internal monitoring (scalp electrode or intrauterine pressure catheter), used when needed, is invasive and can cause discomfort or pain for the mother. Discuss options and concerns with your care team.