Understanding Fetal Heart Rate Monitoring
Here’s why your care provider regularly checks on your baby’s fetal heart rate and rhythm.
Since the 1800s, midwives and obstetricians have listened to baby’s heart rate as one way to check on baby’s wellbeing. Fetoscopes—similar to stethoscopes—were the first technology used to listen in on baby’s beating heart.
Measuring fetal heartbeats can be a reassuring sign that baby is getting adequate oxygen through their placenta and umbilical cord (normal range for babies is 110-160 beats per minute and in this range your baby’s heart can vary by 5 to 25 bpms). Outside of these ranges, baby may not be getting enough oxygen or experiencing other problems.
Fetal Heart Rate Monitoring in Care
During prenatal care, providers typically use a wireless ultrasound device called a Doppler to listen to baby. A fetal Non Stress Test records baby’s heart rate when baby is moving. Late in pregnancy, you may be asked to have a Contraction Stress Test to measure baby’s heart rate during contractions; you may need to be in the hospital with medication to start contractions for this test.
Once you’re in labor, baby’s heart rate is typically checked intermittently unless there are medical reasons to monitor it continuously. The Association of Women’s Health, Obstetric & Neonatal Nurses (AWHONN), which publishes Healthy Mom&Baby, supports fetal heart rate monitoring. AWHONN advises that FHM should happen in ways that are consistent with a pregnant woman’s preferences and desires, and that unless clinical concerns require more increased monitoring, the least invasive ways for checking on baby’s heart rate should be used to promote normal, vaginal labor and birth.
Electronic fetal monitoring involves two devices strapped to your belly via stretchy belts, and attached to the fetal monitoring device by cables:
- Ultrasound transducer: for tracking baby’s heart rate
- Tocodynamometer: for tracking your contractions and uterine activity
If baby’s heart rate can’t adequately be tracked externally, your care provider may want to insert an internal fetal scalp electrode on baby’s head. To put this into place, you lay back in a position similar to a vaginal exam and the tiny scalp electrode is inserted into your uterus and attached to baby’s scalp via a cable extended to the fetal monitoring device.
If your pregnancy care provider needs more information about the intensity and frequency of your contractions, you may also receive an internal device (intrauterine pressure catheter) that sits between your baby and uterine wall, with a cable extending out to a fetal monitor.
When your labor is progressing normally, being upright and moving including rocking on a birthing ball, relaxing between contractions, and staying hydrated all support baby’s heart rate.