Fetal heart rate (FHR) monitoring is used to listen to an unborn baby's heartbeat. There are two types:
- External—A special device records the heartbeat through the belly.
- Internal—A thin wire is threaded into the body and placed on the baby's head.
Reasons for Test
This is done during pregnancy to see how well an unborn baby is doing. It is often done during labor to see how the unborn baby is handling the stress.
External monitoring does not cause any problems. Internal monitoring may raise the risk of infection or bruising on the baby's head.
What to Expect
Prior to Test
The doctor will tell you which type of monitoring will be used and how often. It can be done throughout labor or at certain times.
Description of the Test
External Fetal Monitoring
This type of monitoring may be done in one of two ways:
- Two belts are placed around the belly. Gel is placed under the monitor. This records the unborn baby's heartbeat and tracks how well the uterus is contracting during labor. This type is used throughout labor.
- The doctor uses a special scope to listen to the unborn baby's heart through the belly. This type is used at certain times.
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Internal Fetal Monitoring:
This is only used during labor, after the water has broken and the cervix has opened. A small wire is placed through the vagina and cervix. It is placed on the unborn baby's head. The wire picks up the unborn baby's heartbeat and sends it to a screen. It also tracks how well the uterus is contracting during labor.
How Long Will It Take?
It depends on if it is done throughout labor or at certain times.
Will It Hurt?
An heart rate or pattern may show a problem with the unborn baby. The doctor may make changes based on this information.
The American College of Obstetricians and Gynecologists
Office on Women's Health—US Department of Health and Human Services
The Society of Obstetricians and Gynaecologists of Canada
Women's Health Matters—Women's College Hospital
Fetal heart monitoring. Johns Hopkins Medicine website. Available at: https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/fetal-heart-monitoring. Accessed September 13, 2021.
Fetal heart rate monitoring during labor. The American College of Obstetricians and Gynecologists website. Available at: https://www.acog.org/womens-health/faqs/fetal-heart-rate-monitoring-during-labor. Accessed September 13, 2021.
Fetal monitoring during labor. EBSCO DynaMed website. Available at: https://www.dynamed.com/management/fetal-monitoring-during-labor. Accessed September 13, 2021.
Practice bulletin no. 145: antepartum fetal surveillance. Obstet Gynecol. 2014;124(1):182-192. Reaffirmed 2019.
Last reviewed July 2021 by EBSCO Medical Review Board Mary-Beth Seymour, RN Last Updated: 9/13/2021