External Fetal Monitoring
Norm of External Fetal Monitoring
Fetal heart rate (FHR) and variability normal.
| FHR | 120–160 bpm |
| FHR variability | 5–25 bpm |
Usage of External Fetal Monitoring
Monitoring FHR and uterine contractions, evaluation of fetal effects of stressed and nonstressed situations, assessment of the need for internal fetal monitoring, and monitoring of fetal well-being during the oxytocin challenge test.
Description of External Fetal Monitoring
A noninvasive test in which an electronic transducer is placed on the pregnant abdomen to amplify the FHR while a cardiotachometer records FHR and pressure sensors record uterine contractions. External fetal monitors record fluctuations in the baseline FHR and detect variability between beats. This test is able to detect FHR accelerations and decelerations in response to uterine contractions.
Professional Considerations of External Fetal Monitoring
Consent form NOT required.
Preparation
- Obtain a fetal heart monitor and an electroconductive gel.
- Cleanse the transducer and transducer connections.
Procedure
- The client is placed in a semi-Fowler's or left lateral position with the abdomen exposed.
- The transducer is coated with electroconductive gel and strapped over the abdominal area with the most distinct fetal heart tones. For active labor, this is the fundus.
- The alarm limits for FHR are set, and test recordings are started to ensure that the system is functioning properly.
- For active labor, baseline FHR is recorded and calculated over a 10-minute period and then monitored continuously as labor progresses. The recording is evaluated for abnormalities in FHR and FHR response to contractions, drugs, or maternal position.
- Transducer location may need adjustment in response to fetal movement in utero.
Postprocedure Care
- Weekly external fetal monitoring is indicated for diabetes, hypertension, fetal growth retardation, and pregnancy over 42 weeks of gestation.
Client and Family Teaching
- For antepartal testing, the client should eat a full meal just before the test.
- The test poses no risk of harm to the client or the fetus.
Factors That Affect Results
- Maternal position may cause fetal distress. The left side-lying position best promotes oxygen delivery to the fetus.
- Maternal obesity may interfere with the adequacy of recordings.
- Artifact may result from poor transducer connections, or dried electroconductive gel on the transducer.
Other Data
- Events that cause changes in the FHR recordings during active labor are handwritten on the graphic recording. These include maternal movement, administration of drugs, and procedures.
