Abnormal CTG

abnormal CTG every doctor should know

1. Abnormal CTG Rosshini Jagatheswaran

2. Foetal Tachycardia B aseline heart rate >160 bpm Causes: Chorioamnionitis – if maternal fever also present Thyrotoxicosis Increased foetal activity Drugs ( tocolytic drugs, Vistaril , etc.) Foetal cardiac arryhthmias

3. Foetal Bradycardia indicates severe hypoxia Causes are: Prolonged cord compression Cord prolapse Epidural and spinal anaesthesia Maternal seizures Post-date gestation Occiput posterior or transverse presentations <80bpm  OMNIOUS sign Baseline heart rate < 120bpm `

4. Early Deceleration Physiological Starts when uterine contraction begins R ecover when uterine contraction stops P eriodic slowing of the fetal heartbeat, synchronized with the contractions. C an be due to fetal head compression within the birth canal

5. Late D ecelerations B egin at the beginning of uterine contraction R ecover after the contraction ends Significantly non-reassuring Indicates there is insufficient blood flow through the uterus & placenta, causing foetal hypoxia & acidosis. F resh blood resupplies the intervillous space after the contraction

6. Variable D eceleration Abrupt, visually apparent decreases in FHR below the baseline FHR Start before, during or after uterine contraction starts Seen during labour and in patients with oligohydramnios C aused by umbilical cord compression Corrected by change in maternal position and amniofusion

7. Prolonged Decelerations ≥15 bpm, lasting ≥ 2 minutes, but ≤10 minutes from onset to return to baseline Causes : Maternal hypotension C ord prolapse C ord compression M aternal seizure

8. Reduced V ariability Caused by: Deep foetal sleep - this should last no longer than 40 minutes – most common cause Foetal acidosis (due to hypoxia) Foetal tachycardia Drugs – opiates, benzodiazipines , methyldopa, magnesium sulphate Prematurity – variability is reduced at earlier gestation (<28 weeks) Congenital heart abnormalities

9. Normal variability Reduced variability

10. Sinusoidal Pattern It is described as: Smooth and regular Amplitude of between 5 -15 bpm around the baseline rate No beat to beat variability , accelerations

11. Management of Abnormal CTG District Hospital Refer to hospital if CTG tracing non-reassuring and pathological. Reassure hydration, patient in lateral position and oxygen Hospital with O&G Specialist Non-reassuring/Suspicious CTG – Interpretation : Physiological or early chronic hypoxaemia Action: Inform medical officer in-charge Abnormal/pathological CTG Interpretation : Late chronic hypoxaemia or anaemia acute hypoxaemia ( abruptio placenta) Action: Inform specialist in-charge. Prepare for urgent delivery