When you begin labor, it’s common to have a baseline electronic fetal monitoring (EFM) tracing of at least 20 minutes. After that, how often your baby’s heart rate is evaluated depends on your own health risks, where you are in labor and how it’s progressing for both you and baby.
Fetal monitoring lets your healthcare team assess baby’s heart rate during labor, as well as the frequency of your contractions, and compare the pattern of your baby’s heart rate and its changes to that of a healthy baby during labor.
The goal of fetal monitoring is to ensure that your baby is getting enough oxygen throughout labor and birth. Your baby’s heart rate is one reflection of his oxygen levels.
If your baby’s heart rate is less than reassuring, your healthcare team may advise you of the need for interventions during labor or to undergo cesarean birth to ensure the baby’s oxygen remains stable and sufficient.
There are 3 ways your healthcare team may use fetal monitoring—through auscultation, external electronic or internal fetal monitoring.
With auscultation, your nurse will use a listening device, a Doppler or fetoscope, to hear baby’s heart rate. If you’ve had a healthy pregnancy and are progressing through labor, this may be the only monitoring you need. Your nurse will also assess the strength and duration of your contractions by feeling your abdomen with her fingertips.
External electronic fetal monitoring uses ultrasound and a pressure device on your abdomen attached with stretchy belts to read the fetal heart rate and assess your contractions.
Internal electronic fetal monitoring involves placing an electrode on your baby’s scalp to detect his heart rate, usually once you are slightly dilated. An intrauterine pressure monitor can also be placed inside your uterus to measure your contractions—it’s like taking a blood pressure reading of your uterus.
The goal of fetal monitoring is to evaluate fetal oxygenation and insure that the fetus is getting adequate oxygenation throughout the labor and delivery process. Monitoring is meant to help give you and your baby the best labor and birth outcome possible.
You may need more monitoring if anything unusual is suspected, if you’re receiving medications or before or after your bag of waters is broken.