Obstetric Nurse Intrapartum Fetal Monitoring Questions and Answers — Questions and Answers
Question 1: A laboring patient's electronic fetal monitor (EFM) strip shows a baseline fetal heart rate of 170 bpm for the last 15 minutes, moderate variability, and no decelerations. Which of the following is a likely cause for this finding?
- Maternal fever (Correct answer)
- Fetal sleep cycle
- Umbilical cord compression
- Maternal hypotension
Correct answer: Maternal fever
A baseline fetal heart rate greater than 160 bpm is defined as tachycardia. One of the most common causes of fetal tachycardia is maternal fever or infection (chorioamnionitis). Fetal sleep cycles are associated with decreased variability, cord compression typically causes variable decelerations, and maternal hypotension is more likely to cause bradycardia or late decelerations.
Question 2: An obstetric nurse is analyzing a fetal heart rate tracing and observes a gradual decrease in the FHR that begins after the peak of a contraction and returns to baseline after the contraction has ended. This pattern is identified as:
- Early deceleration
- Variable deceleration
- Late deceleration (Correct answer)
- Prolonged deceleration
Correct answer: Late deceleration
Late decelerations are characterized by a gradual decrease in the fetal heart rate with an onset that occurs after the beginning of the contraction, and the lowest point (nadir) occurs after the peak of the contraction. This timing suggests uteroplacental insufficiency. Early decelerations mirror the contraction, and variable decelerations are abrupt and V-shaped. A prolonged deceleration lasts for 2 minutes or more.
Question 3: A nurse is caring for a patient whose EFM strip displays recurrent late decelerations with minimal variability. According to the NICHD Three-Tier Fetal Heart Rate Interpretation System, this tracing would be classified as which category?
- Category I
- Category II
- Category III (Correct answer)
- Indeterminate
Correct answer: Category III
Category III tracings are abnormal and predictive of abnormal fetal acid-base status. They include patterns such as absent baseline variability with recurrent late decelerations, recurrent variable decelerations, or bradycardia, or a sinusoidal pattern. This combination requires prompt evaluation and intervention.
Question 4: Upon reviewing a fetal monitor strip, the nurse notes several abrupt, V-shaped decelerations that are not consistently related to the timing of contractions. The most appropriate initial nursing intervention is to:
- Administer a tocolytic medication.
- Prepare for an amnioinfusion.
- Discontinue oxytocin if it is infusing.
- Reposition the mother. (Correct answer)
Correct answer: Reposition the mother.
The described pattern is characteristic of variable decelerations, which are typically caused by umbilical cord compression. The initial and least invasive intervention is to change the maternal position (e.g., to a side-lying or knee-chest position) to relieve pressure on the umbilical cord. Other interventions may be necessary if repositioning is not effective.
Question 5: Which of the following is a defining characteristic of a Category I fetal heart rate tracing?
- Baseline rate of 100 bpm
- Presence of recurrent late decelerations
- Moderate baseline variability (Correct answer)
- Minimal or absent variability
Correct answer: Moderate baseline variability
A Category I FHR tracing is considered normal and strongly predictive of normal fetal acid-base status. Its components include a baseline rate of 110-160 bpm, moderate baseline FHR variability, the absence of late or variable decelerations, and accelerations may be present or absent.
Question 6: A patient in the second stage of labor has a fetal heart rate tracing that shows a baseline of 130 bpm, moderate variability, and accelerations with fetal movement. During pushing, the nurse observes gradual, symmetrical decelerations that mirror the contractions, with the FHR returning to baseline as each contraction ends. What is the nurse's best interpretation of this finding?
- Uteroplacental insufficiency requiring intervention.
- Benign head compression from fetal descent. (Correct answer)
- Umbilical cord prolapse requiring immediate action.
- Fetal metabolic acidosis.
Correct answer: Benign head compression from fetal descent.
This scenario describes early decelerations. These are gradual, mirror the contraction, and are caused by fetal head compression during descent, which is considered a benign and reassuring finding, especially in the second stage of labor. It does not indicate fetal distress and requires continued monitoring rather than immediate intervention.
A laboring patient's electronic fetal monitor (EFM) strip shows a baseline fetal heart rate of 170 bpm for the last 15 minutes, moderate variability, and no decelerations.
Which of the following is a likely cause for this finding?