Electronic Fetal Monitoring is when equipment is used to measure your contraction and your baby’s heart rate, this is also called cardiotocography. There are two types of electronic fetal monitoring (EFM), internal and external.
External Fetal Monitoring
External fetal monitoring is where the hospital staff monitors your baby’s heart rate and reaction to contractions through external monitors. The standard monitor set up includes two ultrasound transducers that are held in place on your belly with straps. These transducers are connected to the monitor machines by cables that can be unplugged if you need to move. One transducer, called a tocodynamometer, monitors the frequency and length of your contractions while the other monitors your baby’s heart rate. Some hospitals have a mobile system, where the transducer cables connect to a small box with a strap allowing you or your partner to carry it which enables you to walk around while being monitored. The small box transmits your information to the nurse’s monitor. Some hospitals have a newer wireless EFM system. These systems have transducers that are strapped or taped to your belly and wirelessly send the information to your monitors - these systems are also waterproof which can be good if you want to labor in the shower or tub. Not all hospitals have the mobile or wireless monitors and if they do they only have a limited number, make sure to ask your hospital at the tour.
Internal Fetal Monitoring
Internal fetal monitoring is when a small electronic transducer is inserted vaginally and connected to your baby’s scalp. A tiny metal spiral is on the end of the transducer and is gently poked through the skin of your baby’s scalp to hold it in place and monitor your baby’s heart rate. The procedure will cause a small cut on the top of your baby’s head and may cause some minor bruising. Internal monitoring provides a more accurate reading and prevents the gaps in monitoring that can occur with external monitoring when your baby moves. To allow for internal fetal monitoring, the doctor will need to break your amniotic sac if it hasn’t already broken. Once the transducer is attached to your baby, they will strap or tape the cable to your thigh to prevent it from accidentally being pulled out.
Internal fetal monitoring is used if the hospital staff needs more accurate and consistent monitoring of your baby. They will always try external fetal monitoring first.
Your baby’s heart rate and your contractions will display on the monitor in your room, at the nurse’s station, and the EFM tracings will also print out on graph paper below your monitor so the nurses can look back at your contraction pattern and the baby’s heart rate response. These tracings show your baby’s baseline heart rate and any increases or decreases in this rate. It is normal for certain accelerations and decelerations to occur in response to your contractions. These will also typically be displayed on the monitor in the other rooms your nurses are assigned to with your room number listed below. This allows your nurses to be able to monitor how you and your baby are doing no matter what room they are in. You can also see the monitors of the other patients in your nurses’ care.
Continuous vs. Intermittent Monitoring
Most hospitals prefer continuous fetal monitoring and ask you to sit in bed for the monitoring. This can be very uncomfortable! If your hospital requires continuous monitoring, ask if you can be out of bed standing or sitting on a birth ball. Some hospitals allow intermittent fetal monitoring. This typically involves one hour of monitoring initially, afterwards, as long as your baby shows no signs of distress, they will have you connected to the monitor for 20 minutes and then off the monitor for 40 minutes. This cycle repeats until it is time to push, at which point most hospitals prefer you to be connected to the monitor. You should ask your hospital during your tour what their policy is regarding intermittent monitoring.
Did you have EFM during labor? Were you lucky enough to have a wireless monitor?
Next week I will be blogging on the letter F… F is for Friends and Family.