Fetal Heart Monitoring (2024)

What is fetal heart monitoring?

Fetal heart rate monitoring measures the heart rate and rhythm of your baby(fetus). This lets your healthcare provider see how your baby is doing.

Your healthcare provider may do fetal heart monitoring during latepregnancy and labor. The average fetal heart rate is between 110 and 160beats per minute. It can vary by 5 to 25 beats per minute. The fetal heartrate may change as your baby responds to conditions in your uterus. Anabnormal fetal heart rate may mean that your baby is not getting enoughoxygen or that there are other problems.

There are 2 ways to do fetal heart monitoring, external and internal:

External fetal heart monitoring

This method uses a device to listen to and record your baby’s heartbeatthrough your belly (abdomen). One type of monitor is a Doppler ultrasounddevice. It’s often used during prenatal visits to count the baby’s heartrate. It may also be used to check the fetal heart rate during labor. Thehealthcare provider may also check your baby’s heart rate continuouslyduring labor and birth. To do this, the ultrasound probe (transducer) isfastened to your belly. It sends the sounds of your baby’s heart to acomputer. The rate and pattern of your baby’s heart rate are shown on ascreen and printed on paper.

Internal fetal heart monitoring

This method uses a thin wire (electrode) put on your baby’s scalp. The wireruns from the baby through your cervix. It is connected to the monitor.This method gives better readings because things like movement don’t affectit. But it can only be done if the fluid-filled sac that surrounds the babyduring pregnancy (amniotic sac) has broken and the cervix is opened. Yourprovider may use internal monitoring when external monitoring is not givinga good reading. Or your provider may use this method to watch your babymore closely during labor.

During labor, your healthcare provider will watch your uterine contractionsand your baby’s heart rate. Your provider will note how often you arehaving contractions and how long each lasts. Because the fetal heart rateand contractions are recorded at the same time, these results can be lookedat together and compared.

Why might I need fetal heart monitoring?

Fetal heart rate monitoring is especially helpful if you have a high-riskpregnancy. Your pregnancy is high risk if you have diabetes or high bloodpressure. It is also high risk if your baby is not developing or growing asit should.

Fetal heart rate monitoring may be used to check how preterm labormedicines are affecting your baby. These are medicines are used to helpkeep labor from starting too early.

Fetal heart rate monitoring may be used in other tests, including:

Nonstress test. This measures the fetal heart rate as your baby moves.
Contraction stress test. This measures fetal heart rate along with uterine contractions. Contractions are started with medicine or other methods.
A biophysical profile (BPP). This test combines a nonstress test with ultrasound.

Things that may affect the fetal heart rate during labor:

Uterine contractions
Pain medicines or anesthesia given to you during labor
Tests done during labor
Pushing during the second stage of labor

Your healthcare provider may have other reasons to use fetal heart ratemonitoring.

What are the risks of fetal heart monitoring?

Radiation is not used for this test. The transducer usually causes nodiscomfort.

You may find the elastic belts that hold the transducers in place slightlyuncomfortable. These can be readjusted as needed.

You must lie still during some types of fetal heart rate monitoring. Youmay need to stay in bed during labor.

With internal monitoring, you may have some slight discomfort when theelectrode is put in your uterus.

Risks of internal monitoring include infection and bruising of your baby’sscalp or other body part.

Note:You should not have internal fetal heart rate monitoringif you are HIV positive. This is because you may pass the infection on toyour baby.

You may have other risks depending on your specific health condition. Besure to talk with your provider about any concerns you have before theprocedure.

Certain things may make the results of fetal heart rate monitoring lessaccurate. These include:

Obesity of the mother
Position of the baby or mother
Too much amniotic fluid (polyhydramnios)
Cervix is not dilated or the amniotic sac is not broken. Both of these need to happen to do internal monitoring

How do I get ready for fetal heart monitoring?

Your healthcare provider will explain the procedure to you. Ask him or her any questions you have about the procedure.
You may be asked to sign a consent form that gives permission to do the procedure. Read the form carefully and ask questions if anything is not clear.
The consent form for fetal heart monitoring may be included as part of the general consent for labor and birth.
Tell your healthcare provider if you are sensitive to or are allergic to any medicines, latex, tape, or anesthesia.
If fetal heart rate monitoring is done along with another monitoring test, you may be asked to eat a meal before the test. This can help make your baby more active.
The amniotic sac must be broken and your cervix must be dilated several centimeters before the internal device can be put in place.
Follow any other instructions your provider gives you to get ready.

What happens during fetal heart monitoring?

You may have fetal heart rate monitoring in your healthcare provider'soffice or as part of a hospital stay. The way the test is done may varydepending on your condition and your healthcare provider's practices.

Generally, fetal heart rate monitoring follows this process:

External fetal heart monitoring

Depending on the type of procedure, you may be asked to undress from the waist down. Or you may need to remove all of your clothes and wear a hospital gown.
You will lie on your back on an exam table.
The healthcare provider will put a clear gel on your abdomen.
The provider will press the transducer against your skin. The provider will move it around until he or she finds the fetal heartbeat. You will be able to hear the sound of the fetal heart rate with Doppler or an electronic monitor.
During labor, the provider may check the fetal heart rate at intervals or nonstop, based on your condition and the condition of your baby.
For continuous electronic monitoring, the provider will connect the transducer to the monitor with a cable. A wide elastic belt will be put around you to hold the transducer in place.
The provider will record the fetal heart rate. With continuous monitoring, the fetal heart pattern will be displayed on a computer screen and printed on paper.
You may not be able to get out of bed with nonstop external fetal heart rate monitoring.
Once the procedure is done, the provider will wipe off the gel.

Internal fetal heart monitoring

You will be asked to remove your clothes and put on a hospital gown.
You will lie on a labor bed. Your feet and legs will be supported as for a pelvic exam.
Your healthcare provider will do a vagin*l exam with a gloved hand to see how far you are dilated. This may be slightly uncomfortable.
If the amniotic sac is still intact, your healthcare provider may break open the membranes with a tool. You will feel warm fluid coming out of your vagin*.
Your healthcare provider will feel the part of the baby at the cervical opening with gloved fingers. This is usually the baby’s head.
The provider will put a thin tube (catheter) into your vagin*. He or she will put a small wire at the end of the catheter on the baby’s scalp. He or she will gently turn it on the baby’s skin.
The provider will remove the catheter and leave the wire in place on the baby’s scalp.
The provider will connect the wire to a monitor cable. He or she will keep it in place with a band around your thigh.
You may not be able to get out of bed with nonstop internal fetal heart rate monitoring.
Once the baby is born, the provider will remove the wire.

What happens after fetal heart rate monitoring?

You do not need any special care after external fetal heart monitoring. Youmay go back to your normal diet and activity unless your healthcareprovider tells you otherwise.

After internal fetal heart rate monitoring, your healthcare provider willcheck your baby’s scalp for infection, bruising, or a cut. The providerwill clean the site with an antiseptic.

Your healthcare provider may give you other instructions, based on yoursituation.

Next steps

Before you agree to the test or the procedure make sure you know:

The name of the test or procedure
The reason you are having the test or procedure
What results to expect and what they mean
The risks and benefits of the test or procedure
What the possible side effects or complications are
When and where you are to have the test or procedure
Who will do the test or procedure and what that person’s qualifications are
What would happen if you did not have the test or procedure
Any alternative tests or procedures to think about
When and how will you get the results
Who to call after the test or procedure if you have questions or problems
How much will you have to pay for the test or procedure