NCC C-EFM® CERTIFICATION EXAM: 300 PRACTICE
QUESTIONS WITH ANSWERS AND RATIONALES
DOMAIN 1: ELECTRONIC MONITORING EQUIPMENT (Questions 1-25)
---
Question 1
An internal fetal scalp electrode (FSE) provides a more accurate FHR tracing than
external ultrasound primarily because it:
A) Measures fetal oxygen saturation directly
B) Detects the fetal R-wave from the ECG signal
C) Eliminates all maternal heart rate interference
D) Provides continuous fetal pulse oximetry
Correct Answer: B
Rationale: The FSE detects the fetal R-wave from the fetal electrocardiogram (ECG)
signal, providing a direct and accurate measurement of each fetal heartbeat. This
is superior to external ultrasound, which relies on detecting cardiac valve
movement and can be affected by maternal movement or fetal position. While an
FSE can reduce maternal-fetal heart rate confusion, it does not entirely eliminate
,all interference if the maternal ECG is conducted through the fetus. Internal
monitoring does not measure oxygenation or pulse oximetry directly .
---
Question 2
An intrauterine pressure catheter (IUPC) measures uterine activity in which unit of
measurement?
A) Montevideo units (MVUs)
B) Beats per minute (BPM)
C) Millimeters of mercury (mmHg)
D) Centimeters of water (cmH₂O)
Correct Answer: C
Rationale: An IUPC directly measures intrauterine pressure in millimeters of
mercury (mmHg), providing objective and quantitative data on uterine contraction
frequency, duration, and intensity. Montevideo units are a calculated value (not
directly measured) based on contraction intensity and frequency over 10 minutes.
Beats per minute measure heart rate, and centimeters of water are used for
central venous pressure measurements .
---
Question 3
,What is the primary limitation of an external tocotransducer?
A) It requires ruptured membranes for placement
B) It cannot measure contraction intensity accurately
C) It cannot detect uterine contractions
D) It is invasive and carries infection risk
Correct Answer: B
Rationale: The external tocotransducer detects changes in abdominal wall tension
using a pressure-sensitive device. It can measure contraction frequency and
duration but cannot accurately measure the true intensity (pressure) of uterine
contractions in mmHg. This is because it measures surface tension rather than
actual intrauterine pressure. A tocotransducer does not require ruptured
membranes, is non-invasive, and can detect the presence of contractions .
---
Question 4
A nurse notes that the FHR tracing shows a pattern identical to the maternal heart
rate. Which of the following is the BEST initial action?
A) Document the finding and continue monitoring
B) Reposition the ultrasound transducer to obtain a clearer fetal signal
C) Immediately perform a fetal scalp stimulation
D) Apply an internal fetal scalp electrode without further assessment
, Correct Answer: B
Rationale: When the FHR tracing matches the maternal heart rate, the monitor is
likely detecting the maternal signal rather than the fetal signal (maternal-fetal
heart rate confusion). The initial action should be to reposition the ultrasound
transducer to obtain a clear fetal signal, as this is the least invasive and simplest
intervention. Applying an FSE may be appropriate if repositioning fails, but should
not be the initial action without assessment. Fetal scalp stimulation is an
assessment tool, not a solution for signal confusion .
---
Question 5
Which of the following is a limitation of external fetal monitoring?
A) It cannot assess FHR variability
B) It is invasive and carries infection risk
C) It requires ruptured membranes
D) It may be affected by maternal obesity and fetal position
Correct Answer: D
Rationale: External fetal monitoring is limited by maternal obesity, which
attenuates the ultrasound signal, and fetal position, which may make it difficult to
obtain a clear FHR signal. It is non-invasive, does not require ruptured
membranes, and can assess FHR variability, although variability assessment may
be affected by signal quality .
QUESTIONS WITH ANSWERS AND RATIONALES
DOMAIN 1: ELECTRONIC MONITORING EQUIPMENT (Questions 1-25)
---
Question 1
An internal fetal scalp electrode (FSE) provides a more accurate FHR tracing than
external ultrasound primarily because it:
A) Measures fetal oxygen saturation directly
B) Detects the fetal R-wave from the ECG signal
C) Eliminates all maternal heart rate interference
D) Provides continuous fetal pulse oximetry
Correct Answer: B
Rationale: The FSE detects the fetal R-wave from the fetal electrocardiogram (ECG)
signal, providing a direct and accurate measurement of each fetal heartbeat. This
is superior to external ultrasound, which relies on detecting cardiac valve
movement and can be affected by maternal movement or fetal position. While an
FSE can reduce maternal-fetal heart rate confusion, it does not entirely eliminate
,all interference if the maternal ECG is conducted through the fetus. Internal
monitoring does not measure oxygenation or pulse oximetry directly .
---
Question 2
An intrauterine pressure catheter (IUPC) measures uterine activity in which unit of
measurement?
A) Montevideo units (MVUs)
B) Beats per minute (BPM)
C) Millimeters of mercury (mmHg)
D) Centimeters of water (cmH₂O)
Correct Answer: C
Rationale: An IUPC directly measures intrauterine pressure in millimeters of
mercury (mmHg), providing objective and quantitative data on uterine contraction
frequency, duration, and intensity. Montevideo units are a calculated value (not
directly measured) based on contraction intensity and frequency over 10 minutes.
Beats per minute measure heart rate, and centimeters of water are used for
central venous pressure measurements .
---
Question 3
,What is the primary limitation of an external tocotransducer?
A) It requires ruptured membranes for placement
B) It cannot measure contraction intensity accurately
C) It cannot detect uterine contractions
D) It is invasive and carries infection risk
Correct Answer: B
Rationale: The external tocotransducer detects changes in abdominal wall tension
using a pressure-sensitive device. It can measure contraction frequency and
duration but cannot accurately measure the true intensity (pressure) of uterine
contractions in mmHg. This is because it measures surface tension rather than
actual intrauterine pressure. A tocotransducer does not require ruptured
membranes, is non-invasive, and can detect the presence of contractions .
---
Question 4
A nurse notes that the FHR tracing shows a pattern identical to the maternal heart
rate. Which of the following is the BEST initial action?
A) Document the finding and continue monitoring
B) Reposition the ultrasound transducer to obtain a clearer fetal signal
C) Immediately perform a fetal scalp stimulation
D) Apply an internal fetal scalp electrode without further assessment
, Correct Answer: B
Rationale: When the FHR tracing matches the maternal heart rate, the monitor is
likely detecting the maternal signal rather than the fetal signal (maternal-fetal
heart rate confusion). The initial action should be to reposition the ultrasound
transducer to obtain a clear fetal signal, as this is the least invasive and simplest
intervention. Applying an FSE may be appropriate if repositioning fails, but should
not be the initial action without assessment. Fetal scalp stimulation is an
assessment tool, not a solution for signal confusion .
---
Question 5
Which of the following is a limitation of external fetal monitoring?
A) It cannot assess FHR variability
B) It is invasive and carries infection risk
C) It requires ruptured membranes
D) It may be affected by maternal obesity and fetal position
Correct Answer: D
Rationale: External fetal monitoring is limited by maternal obesity, which
attenuates the ultrasound signal, and fetal position, which may make it difficult to
obtain a clear FHR signal. It is non-invasive, does not require ruptured
membranes, and can assess FHR variability, although variability assessment may
be affected by signal quality .
