McKesson Clinical Reference Systems: Women's Health Advisor 2002.2

External Electronic Fetal Monitoring

What is external electronic fetal monitoring?

Electronic fetal monitoring measures the baby's heart rate and the mother's contractions during labor. External fetal monitoring uses instruments placed on the mother's abdomen. The instruments produce graphs that can be viewed on a screen. This information helps your health care provider know how the baby is doing during labor.

When is it used?

Continuous electronic fetal monitoring is used during labor in all high-risk pregnancies. In low-risk pregnancies, electronic monitors may be used for about 20 minutes at the start of labor, for a few minutes each hour, or all the time.

Continuous electronic monitoring is needed with complications such as:

  • preterm labor
  • births of more than one baby, such as twins
  • bleeding during labor
  • changes in the baby's heart rate found with the stethoscope
  • a very long or very fast labor
  • diabetes or other medical disease
  • high blood pressure.

What happens during the procedure?

The devices for external fetal monitoring are held in place by two belts around the mother's abdomen. On one belt is a pressure gauge, which records the pressure of the contractions. Attached to the other belt is a small ultrasound instrument that records the baby's heart rate. Monitoring is safe and fairly comfortable. You can change positions while the devices are in place, but movement can sometimes disrupt the test recording.

When the baby's heart rate is normal, the monitor may be disconnected at times. You can then move more freely. During most labors the monitor is attached for a few minutes each hour. When the monitor isn't being used, your health care provider may use a stethoscope to check the baby's heart rate every 15 minutes after a contraction.

If the monitor shows that the baby's heart rate is abnormal or your contractions are too frequent, an internal monitor may be used for more accurate information. Internal monitors use an instrument that goes into your uterus and one that is connected to the baby's scalp.

A heart rate that is too slow or does not change as it should with contractions may mean that the baby is not getting enough oxygen. Your doctor may decide that the baby may not do well in a normal vaginal delivery. You may need to have a cesarean section (C-section).

What are the benefits of this procedure?

Electronic fetal monitoring allows your health care provider to check the baby's response to labor. If the baby is not doing well, steps may be taken to help the baby.

What are the risks associated with this procedure?

There are no known serious complications from external electronic monitoring when it is used properly.

Sometimes the information from an external monitor is not completely accurate. This may require the placement of an internal monitor. At all times the monitoring should be evaluated by health care providers who are trained in interpreting it. They need to be able to weigh carefully the many other factors in labor that determine how well the baby is doing.


Developed by McKesson Clinical Reference Systems.
Published by McKesson Clinical Reference Systems.

This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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