Electronic Foetal Monitoring
Electronic fetal monitoring is a continuous test that records your contractions and your baby’s heart rate. It can indicate fetal distress during labor and delivery. Providers use EFM widely, though experts recommend it only for pregnancies that are at high risk of complications.
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.
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.
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 new born 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).
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.
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.
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.
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.