C-EFM EFM Book

Comprehensive and Detailed Explanation From Exact Extract–Based NCC C-EFM References:

The tracing demonstrates:

Baseline: approx. 140 bpm

Variability: minimal-to-moderate (fluctuating but not consistently moderate)

Decelerations: shallow variable decelerations

Accelerations: not consistently present

According to NICHD/NCC definitions:

Category I requires ALL of the following:

Baseline 110–160

Moderate variability

No late or variable decelerations

Early decels and accelerations may be present

This tracing does not have consistently moderate variability and does have variable decelerations, so it is not Category I.

Category III requires ANY of the following:

Absent variability with recurrent late decels

Absent variability with recurrent variable decels

Absent variability with bradycardia

Sinusoidal pattern

This tracing does not show absent variability, bradycardia, or recurrent significant lates.

Category II includes:

Minimal variability

Absence of accelerations

Variable decelerations

Tracings not clearly Category I or III

This strip fits Category II exactly due to minimal variability + intermittent variable decelerations.

Thus, the correct classification is Category II.

Comprehensive and Detailed Explanation From Exact Extract (No URLs):

According to AWHONN Fetal Heart Monitoring Principles & Practice, Simpson & Miller, and the NCC C-EFM Content Outline, fetal heart rate categories are assigned based on baseline, variability, presence/absence of accelerations, and type of decelerations.

A Category II tracing includes any pattern that is not clearly normal (Category I) or clearly abnormal (Category III). Classic Category II features include:

• Bradycardia NOT accompanied by absent variability

• Tachycardia

• Minimal variability

• Marked variability

• Absence of accelerations after stimulation

• Recurrent variable decelerations with minimal or moderate variability

• Prolonged decelerations (≥2 min but <10 min)

In this tracing, the fetus demonstrates:

– A prolonged deceleration with subsequent recovery,

– Presence of baseline variability,

– Return toward baseline but not immediately normal.

AWHONN and Simpson state that any prolonged deceleration automatically places the tracing in Category II unless variability is absent (which would escalate it to Category III). Because variability is present, it cannot be Category III.

Therefore, by NCC standards, this tracing is Category II.

Comprehensive and Detailed Explanation From Exact Extract–Based NCC C-EFM References:

This tracing shows recurrent late decelerations, decreased variability, and subtle baseline shifts—findings that strongly correspond to uteroplacental insufficiency. In trauma cases, NCC emphasizes that placental abruption is the most common fetal complication, caused by shearing forces separating the placenta from the uterine wall.

Key physiologic points per NCC/AWHONN/Menihan:

Maternal blunt abdominal trauma frequently leads to partial or concealed abruption.

Abruption produces decreased uteroplacental blood flow, resulting in:

Late decelerations

Minimal/absent variability

Baseline shifts or instability

Cord accident (option A) typically produces variable decelerations, not late-pattern decelerations.

Fetal trauma (option B) is extremely rare and does not produce a consistent deceleration pattern.

Thus, the physiology most consistent with this tracing and mechanism of injury is placental abruption.

Comprehensive and Detailed Explanation From Exact Extract–Based NCC C-EFM References:

NCC and AWHONN standards state that the fetal heart tones are most clearly heard when the Doppler probe is placed over the fetal back, because:

The fetal heart transmits sound most directly through the fetal spine.

Amniotic fluid and fetal position allow the strongest conduction at the back.

During Leopold maneuvers, identification of the back guides optimal placement.

Placing the Doppler over the abdomen or chest does not provide the strongest or most reliable fetal signal.

Therefore, the correct placement is over the fetal back.