EFM typically involves two types of monitoring: external monitoring and internal monitoring. External monitoring uses two devices placed on the mother's abdomen: a transducer to measure the fetal heart rate and a tocodynamometer to measure uterine contractions. Internal monitoring, on the other hand, involves placing an electrode directly on the fetal scalp to measure the heart rate and a catheter inside the uterus to measure contractions. Internal methods are generally used when more accurate data is required.
