A: It’s a good idea to assess your baby’s well-being during labor. Labor can be a stressful event, and the fetal heart rate provides one way to monitor how your baby is tolerating it.

Normal fetal heart rate is between 120 & 160 beats per minute. A healthy fetal heart rate shows some variation; a reassuring FHR has short periods of accelerations that return to the baseline heart rate. If a fetal heart rate is excessively rapid (called tachycardia) or excessively slow (called bradycardia) it may indicate the fetus is having difficulties. Also, if the baby’s heart rate drops immediately after every contraction, baby may not be receiving adequate oxygen during contractions. When a fetus appears to be in distress, we attempt to correct this or recommend an immediate delivery.

Two main ways to monitor fetal heart rate during labor:

1) Intermittent auscultation. Your nurse or birth attendant listens to the baby’s heart beat with a fetal stethoscope or hand-held Doppler monitor at regular intervals during your labor, usually every 15 minutes.

2) Fetal heart rate monitors. These record the fetal heart rate over longer periods of time. Electronic fetal monitoring (EFM) records the pattern of the fetal heart rate during and between contractions. EFM uses an external Doppler strapped to your belly that is attached to a bedside monitor. If your baby’s heart rate appears abnormal or cannot be well documented using the external probe, an “internal” monitor may be used. The internal monitor is placed directly on your baby’s head during labor; this requires your cervix to be dilated and your bag of water to have already broken. The internal EFM provides the most accurate recording of the fetal heart rate during labor.

Some people have voiced reservations about continuous fetal monitoring. For one thing, it requires you to be attached by a cord to a machine, which restricts your activity during labor. Also, fetal monitoring may reduce your one-on-one contact with a nurse, because nurses can care for more patients at one time when monitors are used. On the other hand, many women feel reassured by having their baby’s heart rate continuously recorded during labor.

While it’s clear that continuous EFM is very important for high-risk situations, the utility of this technology is less clear for low-risk pregnancies. It was originally hoped that the information provided by continuous EFM would improve perinatal outcomes by alerting doctors to situations when fetal asphyxia was of concern. However, interpreting fetal heart rates can be difficult, and many babies may falsely appear to be in distress, prompting some unnecessary Casarean sections. In low-risk situations, studies suggest that intermittent monitoring may be just as safe for babies as continuous monitoring.