Electronic fetal heart monitor: what to know

Two sensors are usually placed against your abdomen with soft straps. One listens to the fetal heartbeat, while the other detects tightening of the uterus. The equipment produces a continuous tracing that shows the heart rate pattern, changes with movement, and its relationship to contractions. A clinician interprets the whole pattern rather than one isolated rise or dip. The monitor may be used during a check in late pregnancy, after concerns about movement, or during labour when closer observation is needed.

Monitoring can be external and non-invasive, although the straps may feel snug and the sensors may need repositioning if you or the baby moves. A normal-looking trace is reassuring at that moment, but it does not predict every later event.

Wear comfortable clothing and tell the midwife if the straps feel painful, your skin becomes irritated, or you need to change position. Try to remain still enough for the sensor to pick up the heartbeat, while asking for help to move safely. Tell the team when you feel fetal movement and report pain, bleeding, fluid leakage, dizziness, or a sudden change in how you feel. Do not try to interpret the printed line yourself; ask what the tracing means and whether monitoring will continue.

Contact your maternity unit promptly for reduced or absent fetal movement, vaginal bleeding, suspected waters breaking, regular painful contractions before your expected labour, severe abdominal pain, fainting, or trouble breathing. If you are already being monitored, alert the team immediately about any new symptom instead of waiting for the trace to change. The monitor is an assessment tool and does not replace urgent clinical review.

Ask why monitoring is recommended, how long it may last, whether you can change position, what the tracing currently shows, and what would lead to further assessment or a different plan.