Electronic Fetal Monitoring (EFM)

What is electronic fetal monitoring?

Electronic fetal monitoring (EFM) is a way for your pregnancy care provider to track your baby’s heart rate and your contractions during labor. It provides continuous, real-time information about how your baby is doing. It may also be used as part of a prenatal visit to see how the fetus is doing.

Contractions can slow down blood flow to your baby. This happens because contractions squeeze the blood vessels that carry oxygen. Most of the time, babies still get enough oxygen. But if levels drop too low, it can affect your baby’s heart rate. Monitoring their heart rate allows your provider to spot any problems and take steps to keep your baby safe.

EFM is typically recommended when:

• Your pregnancy is high risk for any reason.
• Your labor is induced or assisted with medication (like an epidural or Pitocin®).
• Your baby has a congenital abnormality.
• There are signs of fetal distress.

How does EFM work?

EFM uses sensors that track and record your baby’s heart rate and your contractions. Your provider can see both activities on a computer screen. They can also print a readout on paper. They watch how your baby’s heart rate changes during contractions.

Changes that may indicate a problem include:

• Above normal (tachycardia) or below normal (bradycardia) heart rate for an extended period of time
• Abnormal slowing or speeding up of the heart rate

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

What are the types of electronic fetal monitoring?

There are two types: external and internal.

External EFM is the most common type. Your provider uses elastic strips to secure two sensors to your abdomen. One sensor measures fetal heart rate. The other measures the frequency of your contractions.

Internal monitoring is less common and only an option if your water has broken. Providers use it when external EFM is unreliable or when they need more precise readings. Your provider inserts a small wire through your vagina and attaches it to the skin on your baby’s head. This tracks its heart rate. Your provider may insert a different catheter through the opening to your uterus to measure your contractions.

What are the risks?

There can be disadvantages to EFM, including:

• Lead to false alarms that can cause you stress
• Limit your ability to move around, which is beneficial during labor
• Lead to a false concern for fetal distress, resulting in a C-section or delivery with a vacuum or forceps

Internal EFM carries additional risks. The wire and catheter may cause:

• Injury to your baby’s scalp
• Risk of uterine or vaginal infection
• Passing of HIV from mother to baby
• Uterine or placental tears

What happens if EFM shows fetal distress?

Your provider will check the continuous readout while you’re in labor. They’ll watch for any signs of problems. An abnormal EFM reading doesn’t necessarily mean your baby is in danger. It just means your pregnancy care team may need to act to keep you and your baby safe.

They may do any of the following if they notice irregular patterns:

• Have you change positions (improves blood flow).
• Give you oxygen through a mask (helps your baby get more oxygen).
• Give you IV fluids (helps with blood flow).
• Adjust your labor medications.

If these steps don’t help, your pregnancy care provider may recommend delivering your baby right away.

Is EFM used before labor?

Sometimes. EFM gives your provider information about the health of the fetus. They may use it during pregnancy if you experience trauma to your belly after 20 weeks of pregnancy. EFM can also help your provider distinguish between true and false labor.