EFM - Electronic Fetal Monitoring Periodic and Episodic Changes Questions and Answers

Question 1

A fetal heart rate tracing shows recurrent decelerations where the onset, nadir, and recovery are delayed relative to the beginning, peak, and end of the uterine contractions. This pattern is most indicative of which underlying condition?

Accepted Answer

Uteroplacental insufficiency

Answer

Late decelerations are characterized by a gradual decrease in the FHR with the nadir occurring after the peak of the contraction. This timing reflects a delayed fetal response to transient hypoxemia caused by reduced blood flow to the intervillous space during a contraction, which is the hallmark of uteroplacental insufficiency. [2, 3, 16]

Question 2

According to the 2008 NICHD guidelines, which of the following defines a fetal heart rate acceleration for a fetus at 34 weeks gestation?

Accepted Answer

An abrupt increase of at least 15 bpm above baseline, lasting at least 15 seconds but less than 2 minutes.

Answer

For a fetus at 32 weeks of gestation or greater, an acceleration is defined as a visually apparent abrupt increase (onset to peak <30 seconds) in the FHR from the baseline. The peak must be at least 15 bpm above the baseline, and the duration must be at least 15 seconds but less than 2 minutes from the onset to the return to baseline. [5, 7, 10]

Question 3

A laboring patient's EFM tracing shows an abrupt FHR decrease from a baseline of 145 bpm to a nadir of 90 bpm. The onset of the deceleration to the nadir is less than 30 seconds. This change is best described as a:

Accepted Answer

Variable deceleration

Answer

A variable deceleration is defined by its abrupt onset (onset to nadir in <30 seconds). It is a visually apparent decrease in the FHR of at least 15 bpm, lasting at least 15 seconds but less than 2 minutes. This pattern is typically caused by umbilical cord compression. [1, 5, 6]

Question 4

A clinician notes a visually apparent, smooth, sine wave-like undulating pattern in the FHR baseline with a frequency of 3-5 cycles per minute that persists for 25 minutes. This pattern is defined as a sinusoidal pattern and is a Category III tracing, often associated with which condition?

Accepted Answer

Severe fetal anemia

Answer

A true sinusoidal pattern is an ominous finding associated with high rates of fetal morbidity and mortality. It is most commonly linked with severe fetal anemia, which can result from conditions like Rh isoimmunization or significant fetal-maternal hemorrhage. [4, 9, 18]

Question 5

A fetal heart rate deceleration begins at a baseline of 130 bpm, drops to 80 bpm, and lasts for 4 minutes before returning to the previous baseline. According to NICHD guidelines, how should this event be classified?

Accepted Answer

A prolonged deceleration

Answer

A prolonged deceleration is defined as a decrease in the FHR from the baseline of at least 15 bpm, lasting for at least 2 minutes but less than 10 minutes. A deceleration lasting 10 minutes or more is considered a baseline change. [1, 7, 21]

EFM - Electronic Fetal Monitoring Practice Test

EFM - Electronic Fetal Monitoring Practice Test

EFM - Electronic Fetal Monitoring Periodic and Episodic Changes Questions and Answers