In plain language: Fetal monitoring during labor (external, internal, intermittent, continuous, and wireless)
Fetal monitoring often gets talked about like it’s one setup, but in practice it’s three separate questions layered on top of each other: where the monitor is placed, how often it’s recording, and whether it’s connected with wires to a console. Once you understand these three options, it’s a lot easier to know what your preference might be.
What does fetal monitoring measure?
Fetal heart rate monitoring measures and tracks your baby’s heart rate over time. It’s usually done alongside contraction monitoring, since a change in baby’s heart rate can mean something different during a contraction versus between contractions.
What’s the difference between external and internal fetal monitoring?
External monitoring uses two small, plastic discs that are held on your belly with elastic bands. One disc sits over your uterus for contractions, and one sits over baby for their heart rate. You may hear the belt called a TOCO (short for tocodynamometer). The discs are attached by wires to a console that stays in place near your bed.
Internal monitoring of baby’s heart rate uses a device with a small wire electrode (called a fetal scalp electrode, or FSE) attached directly to baby’s scalp. There is a separate device with a small plastic tube (called an intrauterine pressure catheter, or IUPC) that sits inside your uterus and measures contractions. Sometimes only one of these internal monitoring methods is used alongside external monitoring for the other measurement (an internal fetal heart rate monitor with an external contraction monitor, for example).
Either internal monitoring device requires that your water is broken and your cervix is at least a little dilated. In my experience, providers usually offer internal monitoring when the external methods aren't picking up a reliable signal, or when they want a more precise reading.
What’s the difference between intermittent and continuous monitoring?
Continuous monitoring means baby’s heart rate is tracked the whole time you’re in labor at the hospital, without breaks.
Intermittent monitoring means checking baby’s heart rate at regular intervals. In my experience in Baltimore hospitals, this often looks like 40 minutes on the monitors, then 20 minutes off the monitors. Providers often want to see a fetal heart rate pattern that is steady and healthy for the whole 40 minutes before agreeing to a break, so if there are any questions about baby’s heart rate, it might mean moving to continuous monitoring even if intermittent was the original plan.
There is a type of non-electronic monitoring called intermittent auscultation (IA), which is more commonly used among midwives, at birth centers, and at home births. This involves the provider (not a machine) feeling for contractions and listening for the fetal heart rate, often with a handheld fetal Doppler device.
What is wireless monitoring?
Wireless (or telemetry) monitoring uses an adhesive sticker patch that is placed on your belly that sends both baby’s heart rate and your contraction pattern to the console without needing a wire. It doesn’t change how often you’re monitored (in fact, everyone I’ve worked with who used wireless monitoring had continuous monitoring), only your mobility. You can move around the room, labor in the shower, or sit on a birth ball while baby’s heart rate and your contractions are still being monitored.
What is a walking monitor?
A walking monitor has the same setup as the discs and elastic bands used in external monitoring, but the console they are wired to sits on a mobile cart, so you can walk around the room.
A quick reference
| What it answers | Options | |
|---|---|---|
| Placement | Where the monitor is |
External: two discs held on your belly with elastic bands
Internal: an electrode for fetal heart rate and a catheter for contractions (once your water has broken and your cervix is somewhat dilated) |
| Frequency | How often it's on |
Continuous: the whole time
Intermittent: regular intervals |
| Mobility | How much you can move |
Wired: attached with cords to a console that stays by the bed
Walking: attached to a console on a cart you can walk around with Wireless: no cords |
How do I know what type of monitoring I can have or want?
This is a great discussion to bring up with your provider during a prenatal appointment. In my experience, the default when you’re admitted is continuous, external, wired monitoring, and if you want anything different, you have to ask.
What’s available can depend on a few things. Not every hospital has wireless monitors or staff trained to use them, and where they do exist, there may only be one or two units on the floor. What’s recommended can also depend on other factors, like if you’re in preterm labor or have a condition like diabetes.
And - your decision can change! I’ve worked with many people who have started on the wireless monitor then moved to the wired ones, and the other way around.
How a doula can help
Your doula can help you figure out what questions to ask your provider ahead of time - what’s typical at your hospital, whether a wireless monitor is available on the unit, or what “intermittent” looks like in practice - so you’re choosing between options you understand. If a provider seems reluctant about the monitoring you want, your doula can help you ask why, and work through the conversation together, so you're not navigating that pushback alone.
Explore this further
Evidence Based Birth: Evidence on Fetal Monitoring - a deep dive the research on continuous versus intermittent monitoring
ACOG: Fetal Heart Rate Monitoring During Labor - a patient-facing FAQ on how monitoring works and what the terms mean
Cleveland Clinic: Fetal Heart Rate Monitoring - an overview of external and internal monitoring, including what to expect during each