Electronic Fetal Monitoring (EFM)

What is electronic fetal monitoring?

Electronic fetal monitoring (EFM) is a test your healthcare provider uses to track your baby’s heartbeat during labor or in the office. It provides real-time, continuous information about how your baby is doing through labor and delivery.

Why is electronic fetal monitoring done?

Labor contractions squeeze the blood vessels that supply your baby with oxygenated blood. Usually, babies’ oxygen levels remain sufficient throughout labor. But if blood oxygen levels decrease, your baby’s heart rate will change.

By monitoring your baby’s heart rate, your provider can identify concerns and take steps to protect your baby. In rare cases, drops in oxygen levels can cause fetal distress.

Is electronic fetal monitoring necessary?

Some studies have found that routine EFM increases the rates of unnecessary cesarean sections and deliveries using vacuum devices or forceps. Also, EFM is not associated with better newborn Apgar scores or lower rates of:

• Cerebral palsy.
• Developmental delays.
• Neurologic injuries.
• Admissions to neonatal intensive care units (NICUs).

Most experts believe EFM is unnecessary in pregnancies at low risk of complications. Providers can check your baby’s heart rate periodically with a stethoscope or ultrasound device (intermittent auscultation).

When is electronic fetal monitoring recommended?

The latest recommendations from the American College of Obstetricians and Gynecologists call for EFM when labor is induced or assisted with medication, such as an epidural. EFM is also used in pregnancies considered high risk due to:

• Maternal health conditions such as preeclampsia, diabetes, previous cesarean or bleeding during pregnancy.
• Meconium staining during labor, which is the release of stool by your baby and can indicate fetal distress.
• Small fetal size or congenital abnormalities.

Despite these recommendations, many Ob/Gyns still routinely use EFM.

Is electronic fetal monitoring used before labor?

During pregnancy, providers may use EFM to assess the health of the fetus, especially after trauma to your belly. If you experience a traumatic event after 20 weeks of gestation, your provider may recommend monitoring for a period of 4 to 24 hours.

EFM can also help your provider distinguish between true vs. false labor. Signs of false labor include:

• Irregular contractions that don’t get closer together.
• Contractions that stop when you walk, rest or change position.

What are the types of electronic fetal monitoring?

External EFM is the most common type. Your provider uses elastic strips to secure two measuring devices to your abdomen. An ultrasound device positioned over your abdomen measures fetal heart rate. A pressure gauge placed at the top of your abdomen measures the frequency of your contractions. But, it doesn’t accurately measure the intensity of contractions.

Less often, providers use internal monitoring. It’s more invasive, but helps when getting a continuous heart rate is limited by movement. A wire inserted through your vagina attaches to the skin on your baby’s head to track the heart rate. Your provider may also insert a catheter into your uterus to measure contractions.

Internal EFM is only an option if your water has broken. Providers use it most often when the external EFM readout is unreliable or where more precise monitoring is needed.

How does electronic fetal monitoring work?

The devices connect to an external monitor that records the activity on an electronic or paper readout.

Your provider will obtain the baby’s baseline heart rate and check the readout periodically. Some changes in fetal heart rate during contractions are normal. Changes that may indicate a problem include:

• Above normal (tachycardia) or below normal (bradycardia) heart rate for an extended period of time.
• Abnormal patterns of heart rate slowing during contractions.

The EFM device may also have alarms set up that notify your labor and delivery team of changes in your baby’s heart rate.

Does electronic fetal monitoring restrict movement?

External EFM will limit your movement to your bed and chair. Some hospitals offer wireless telemetry monitoring for external EFM, which allows you to move around more freely. With internal EFM, you'll need to stay in bed.

What are the risks of electronic fetal monitoring?

Electronic fetal monitoring can:

• Lead to false alarms that can cause stress.
• Limit your ability to move around, which is beneficial during labor.
• Lead to a false concern for fetal distress resulting in a cesarean section or operative delivery using a vacuum device or forceps.

Internal EFM carries additional risks. The wire used in internal EFM can lead to:

• Injury to your baby’s scalp.
• Maternal infection.
• Transmission of HIV or genital herpes from birthing parent to baby.

The catheter inserted into your uterus to measure pressure can:

• Become tangled with the umbilical cord (uncommon).
• Puncture your uterus (rare).
• Tear the placenta (rare).

When should I know the results of the test?

Your provider will check the continuous readout throughout your labor and let you know how your baby is doing.

What will happen if electronic fetal monitoring indicates fetal distress?

An abnormal EFM reading doesn’t necessarily mean your baby's in danger. Your provider may ask you to change position, which may improve blood flow.

If certain heart rate patterns persist, your provider will consider immediate cesarean section or vaginal delivery using a vacuum device or forceps.

A note from Cleveland Clinic

In some cases, EFM can provide reassurance that your baby is doing well and identify problems that call for immediate delivery. But electronic fetal monitoring isn’t necessary for most people with healthy, low-risk pregnancies and unmedicated labor. As you plan to deliver your baby, talk to your healthcare provider about their standard practices for EFM. By discussing your preferences ahead of time, you can be prepared to make the best choices for you and your baby.