What is external fetal monitoring?

External fetal monitoring is a test done during pregnancy and labor. It uses devices placed on your belly to measure your baby’s heart rate. When used during labor, it also measures your contractions.

When is it used?

This test may be done during late pregnancy to check your baby. When it is done during labor, it may be done for about 20 minutes at the start of labor and then off and on for a few minutes each hour. If your pregnancy is high risk, monitoring is done all the time you are in labor. For example, it may be done throughout labor if you are pregnant with more than 1 baby, you are older than 35, you have high blood pressure, or your baby is early or very small.

What happens during the procedure?

The instruments used for external monitoring are strapped to your belly with 2 elastic belts. One belt has a small ultrasound device to record your baby’s heart rate. The other belt has a gauge to record your contractions during labor. The results are viewed as graphs on a TV screen.

The monitor may show problems that may mean that the baby is not getting enough oxygen. For example:

• Your baby’s heart rate is too fast or too slow.
• Your contractions are too frequent.

An internal monitor may then be used. An internal monitor uses instruments put through your vagina and onto your baby’s scalp. It can give more accurate information about your labor and baby.

If your baby is not getting enough oxygen, you may need a C-section. A C-section is an operation that delivers your baby through a cut in your belly and uterus.

What are the risks of this procedure?

This test has no known risks, but the results of external monitoring by itself may not be completely accurate. Ask your healthcare provider about any questions or concerns that you may have.