To read a contraction monitor, look at the bottom line. Each hill is one contraction. Time it from the start of one hill to the start of the next. That tells you how often they come. The top line shows your baby’s heart rate.
The screen beside the bed shows lines, spikes, and numbers. Nobody explains them. Want to know how to read a contraction monitor? You are in the right place. It looks hard, but it is not. You only need to find one line and count minutes. This guide shows you how to read a contraction monitor in plain words. You will learn which line matters and how to time each contraction. You will also see what the numbers really mean. No medical degree needed. Let’s start simple. Take a breath. You can learn this.
Which Line Is Which on the Monitor?
Most monitors draw two graphs, one above the other. Two belts feed them.
Top graph: Your baby’s heart rate. The line looks squiggly.
Bottom graph: Your contractions. The line looks like hills.
The contraction sensor is called a toco. It sits high on your belly, over the top of your uterus. The heart rate sensor sits lower, where your nurse finds the heartbeat.
Time runs left to right. On many US printouts, each bold vertical line equals one minute. Each small box equals 10 seconds. Check the scale on your paper. Digital screens show a clock instead.
How to Read a Contraction Monitor, Step by Step
Find the bottom line. Ignore the top graph for now. You are only reading contractions.
Spot the hills. The line sits flat between contractions. When one starts, it climbs. It reaches a peak. Then it drops back down. One full hill is one contraction.
Time how often they come. Measure from the start of one hill to the start of the next. This is called frequency. Say hill one starts at 10:00 and hill two starts at 10:04. They are four minutes apart.
Time how long each one lasts. Measure from the start of the hill to the end. If it starts at 10:00:00 and ends at 10:01:00, that contraction lasts one minute.
Watch the pattern. Look at about 10 minutes of the line. Do the hills come closer together? Do they last longer? Do they grow taller? A pattern like that often means labor is moving forward.
What the Numbers on a Contraction Monitor Really Mean
This is where many guides go wrong. On a standard belt monitor, the numbers are not real pressure. They are relative. They show how hard your belly pushes on the sensor.
Belt tightness, your position, and your body shape all change the number. A 40 for one person can mean something very different for another. So read the pattern, not one number. Online charts that say “40 to 60 is strong” are wrong for belts.
That is why your nurse also touches your belly. By feel, they label each contraction mild, moderate, or strong.
True pressure needs an intrauterine pressure catheter, or IUPC. It is a thin tube placed inside the uterus after your water breaks. Providers use it in special cases, like some inductions or slow labor. It reads in mmHg. Providers add up the pressures over 10 minutes. These are called Montevideo units. About 200 is considered adequate. A belt monitor cannot give you that math.
Early Labor vs. Active Labor on the Screen
Every labor is different. These ranges are a general guide.
Early labor: Hills come about 5 to 20 minutes apart. Each lasts 30 to 60 seconds.
Active labor: Hills come about 3 to 5 minutes apart. Each lasts about 60 seconds.
Transition: Hills come about 2 to 3 minutes apart. Each lasts 60 to 90 seconds.
Ask your nurse what they see in your pattern. They know your full picture.
What the Top Line Shows
The top line is your baby’s heart rate. A normal baseline is usually 110 to 160 beats per minute. During labor, the line rises and dips. Some changes are normal. Some need action.
Your nurse or doctor reads how the heart rate changes with each contraction. That takes training. Do not try to judge it yourself. Worried about a dip? Ask, “Is my baby’s heart rate okay?” A good team will answer.
Why the Monitor Line Looks Odd
The line is flat, but you feel contractions
The belt may be loose or may have slipped. Your baby may have shifted. Ask your nurse to adjust it.
The line spikes suddenly
Coughing, vomiting, and moving can spike the line. Those spikes are not always contractions.
The heart rate line has gaps
Your baby may have moved, or the belt may have slid. Tell your nurse. They can reposition it.
The tracing is hard to read
Body shape can make a belt less accurate. Your nurse may rely on touch. They may suggest an internal catheter.
You have an epidural and feel less
The screen still shows each contraction. You may feel less. The monitor does not.
When to Call Your Provider or Go In
Many providers use the 5-1-1 rule. Contractions come five minutes apart, last one minute, and keep going for one hour. Some use 4-1-1 or 3-1-1. Follow the plan your provider gave you.
At home, a timer app works like the monitor. Tap start when a contraction begins. Tap stop when it ends. The app figures out how far apart they are.
Call right away if any of these happen:
Your water breaks.
You have bleeding.
Your baby moves less than usual.
The pain is constant and severe.
Regular contractions start before 37 weeks.
Questions to Ask Your Nurse
“How far apart are my contractions right now?”
“Are they getting stronger?”
“Is the belt in the right spot?”
“What should I watch for next?”
This guide is for general education. Your care team makes medical decisions.
People Also Ask
What does a contraction look like on a monitor?
It looks like a hill on the bottom graph. The line starts flat, climbs to a peak, and falls back to flat. One hill equals one contraction.
What number on the monitor means a strong contraction?
No single number does. Belt monitors show relative pressure, not mmHg. Belt fit and body shape change the number. Nurses judge strength by feeling your belly.
How do you tell how far apart contractions are on a monitor?
Measure from the start of one hill to the start of the next. Do not measure from the end of one to the start of the next. Average a few hills over 10 minutes.
Does the monitor show how much a contraction will hurt?
No. Pain is personal. The monitor shows timing and rough shape. Two people with the same line can feel very different pain.
Which line on the monitor is the baby’s heartbeat?
The top graph. It shows beats per minute and looks squiggly. The bottom graph shows contractions.
Conclusion
A contraction monitor is just a map of what your body is doing. You do not need to read every line. Find the hills, count the minutes, and trust your care team with the rest. Your body knows this work. Each hill on that screen shows you doing something strong and real. Breathe through it. Ask questions when you feel unsure. When the screen feels like too much, look at the people beside you. Stay calm. You’ve got this, and you are not alone.
I am Arden Klyne, a California-based writer who turns complex ideas into simple, compelling stories.
My work blends creativity with strategy, helping content feel both engaging and purposeful.
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