EFM Certified - Electronic Fetal Monitoring Question and Answers

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

NCC and AWHONN explain that Contraction Stress Testing (CST):

Has a higher rate of equivocal (“equivocal–suspicious” or “equivocal–hyperstimulation”) results

Frequently must be repeated or replaced with other tests

Requires inducing contractions, which carries risk (hyperstimulation, preterm labor, uterine rupture in scarred uterus)

NST is used more commonly because it is:

Noninvasive

Easier to perform

Has fewer contraindications

Has a lower rate of equivocal results

Why the others are incorrect:

B — CST does detect fetal compromise reliably and is NOT limited in its reporting structure.

C — A negative CST actually has very high negative predictive value for 7 days, making this answer incorrect.

Thus the correct choice is A. Higher frequency of equivocal results.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

NCC/AWHONN emphasize that the primary goal of intrauterine resuscitation is to:

Optimize uteroplacental blood flow, which restores fetal oxygen delivery.

Key measures include:

Maternal repositioning (lateral)

Reducing tachysystole

IV fluid bolus

Correcting maternal hypotension

Stopping oxytocin

Treating underlying causes

Improving maternal oxygenation is supportive, but improving uteroplacental perfusion is the critical first determinant of resuscitation success.

Why the other answers are not first priority:

A. Oxygen — optional and no longer universally recommended unless maternal hypoxemia exists.

B. Minimizing uterine activity — essential, but still secondary to restoring perfusion.

Correct answer: C. Optimizing uteroplacental blood flow

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

NCC references (AWHONN, Menihan, Simpson, Creasy & Resnik) consistently state that fetal accelerations are a reassuring sign of intact neurologic function. Accelerations represent the interaction of both the sympathetic and parasympathetic branches moderated through the central nervous system, reflecting effective autonomic regulation.

AWHONN specifically describes fetal accelerations as:

• A maturity marker of CNS function,

• Reflecting vigorous fetal movement,

• Demonstrating adequate oxygenation,

• Indicating a well-oxygenated brainstem and cortex.

Simpson & Miller emphasize that accelerations require both systems to be functioning and respond appropriately, which confirms CNS integration, not sympathetic or parasympathetic dominance alone.

Therefore, spontaneous accelerations indicate an integrated CNS response, making Option C the correct NCC-aligned answer.

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

According to AWHONN’s Fetal Assessment Text, Simpson & Miller, and Menihan, vibroacoustic stimulation is utilized during NSTs to elicit fetal accelerations, thereby minimizing testing time.

NCC-referenced sources describe VAS as:

• A method that awakens the fetus,

• Stimulates the fetal auditory system,

• Produces reactive accelerations in a neurologically intact fetus,

• Dramatically shortens NST duration, especially when the fetus is in a sleep cycle.

VAS does NOT measure amniotic fluid, nor does it have any effect on uterine activity (therefore cannot treat tachysystole).

The only correct purpose supported by NCC-cited literature is that VAS shortens the duration of the NST, making Option C correct.

Comprehensive and Detailed Explanation From Exact Extract Sources:

The tracing demonstrates an abrupt-onset, sharp, V-shaped deceleration, occurring simultaneously with or slightly after a contraction—classic for variable decelerations, which are caused by umbilical cord compression.

According to AWHONN Fetal Heart Monitoring Principles & Practices, variable decelerations are defined by:

“Abrupt decreases in FHR below baseline of at least 15 bpm, lasting at least 15 seconds and less than 2 minutes.”

“Most commonly associated with umbilical cord compression, whether transient or recurrent.”

Physiology reference (Simpson & Miller, Pocket Guide):

Compression of the umbilical vein causes a brief acceleration.

Compression of the umbilical arteries triggers a vagal response, producing a rapid deceleration.

This creates the characteristic sharp ‘V’, ‘U’, or ‘W’ shape on the monitor.

Placental insufficiency (Choice B) produces late decelerations, which are gradual, not abrupt.

Fetal head compression (Choice A) produces early decelerations, which mirror contractions and have a gradual pattern.

Thus, the tracing is most consistent with variable decelerations caused by umbilical cord compression.

Comprehensive and Detailed Explanation From Exact Extract Without Links:

NCC-recommended references (Simpson, AWHONN FHM, Creasy & Resnik) note that baseline increases within the normal range (110–160 bpm) accompanied by moderate variability are typically benign. Mild physiologic causes—maternal activity, fetal stimulation, or normal sympathetic activation—may transiently raise baseline FHR.

AWHONN stresses that intervention is required only when tachycardia exceeds 160 bpm or when variability is minimal/absent or accompanied by recurrent decelerations.

Here, the baseline increase to 150 bpm remains within normal limits and is paired with moderate variability, which the NCC recognizes as the strongest indicator of adequate fetal oxygenation.

Therefore, evaluation is complete, and continued observation is the appropriate course.

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

An early deceleration is defined by NICHD and NCC as a gradual decrease and return of the fetal heart rate associated with uterine contractions. NCC emphasizes that early decelerations are:

Symmetrical

Uniform in shape

Mirror images of the contraction

This means:

Onset of deceleration = onset of contraction

Nadir of deceleration = peak of contraction

Recovery = end of contraction

Duration of the deceleration ≈ duration of the contraction

Thus, the correct answer is C. The same.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

This tracing shows:

Baseline ~145 bpm

Minimal variability

No accelerations or decelerations

Very little fluctuation → resembles a flat/minimal variability Category II tracing

The key physiologic mechanism behind minimal variability in the presence of a normal baseline and normal contraction pattern is most often:

Increased fetal sympathetic tone, driven by catecholamine release (epinephrine and norepinephrine).

NCC and AWHONN explain:

Catecholamine release (due to fetal stress, early hypoxemia, or maternal stress) results in:

Reduced beat-to-beat fluctuation

Minimal baseline variability

This is considered an early compensatory mechanism, not yet a decompensated hypoxic state.

Why the other answers are incorrect:

A. Myocardial hypoxic depression

Causes absent variability, NOT minimal variability.

Represents advanced or severe hypoxia. The FHR here is not absent variability.

C. Vagal stimulation in response to hypoxemia

Produces decelerations, especially late or prolonged.

This strip shows no decelerations, ruling this out.

Therefore the most accurate physiologic explanation is B. Release of catecholamines.

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

Evaluation of a tracing during oxytocin induction requires analysis of fetal status (baseline, variability, accelerations, decelerations) and uterine activity, with attention to tachysystole and fetal intolerance. NCC, AWHONN, Miller, Menihan, Simpson, and the NICHD guidelines all emphasize that oxytocin must be adjusted based on fetal response and contraction frequency.

Baseline:

The fetal heart rate baseline is approximately 150 bpm, which is within the normal range of 110–160 bpm.

Variability:

The tracing shows minimal variability (approximately 1–4 bpm amplitude). Minimal variability for a sustained period is categorized as a Category II pattern under NCC/NICHD classification.

Accelerations:

No accelerations are present during the 20-minute representative segment.

Decelerations:

There are no recurrent variable, no recurrent late, and no prolonged decelerations.

Uterine Activity:

The tracing shows very frequent contractions—approximately every 1½ to 2 minutes, which meets the NCC definition of tachysystole when averaged over 10 minutes (more than 5 contractions in 10 minutes).

According to NCC and AWHONN standards, when tachysystole is present with minimal variability, oxytocin must be reduced or discontinued even in the absence of late decelerations.

Clinical decision-making (per NCC principles):

NCC emphasizes that management of Category II patterns during induction starts with intrauterine resuscitative measures, including decreasing or stopping oxytocin when uterine activity is excessive or fetal response is suboptimal. Minimal variability with tachysystole requires correction of uterine stimulation before escalating to invasive monitoring or considering operative birth.

Option B (place a spiral electrode) is not indicated because the pattern is clearly visible and the priority is correcting uterine overstimulation, not refining the tracing.

Option C (operative birth) is not indicated; there is no Category III pattern or recurrent decelerations.

Option A (discontinue oxytocin) is the correct first-line action according to NCC-aligned guidelines when tachysystole and minimal variability occur.

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

NCC and AWHONN consider fetal movement counts normal when:

≥10 distinct movements occur within 2 hours

Or ≥4 movements in 1 hour for certain protocols

Or ≥10 movements in 1 hour (common triage threshold)

This patient reports 12 movements in 1 hour, which is reassuring and requires no further testing.

Thus, recommending she continue daily kick counts at home is appropriate.

Why the other options are incorrect:

A. NST is not needed because movements are normal.

B. Continue to monitor is unnecessary; the test is already reassuring.

Correct choice: C. Count again the next day.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

This tracing shows:

Baseline ~170–175 bpm → fetal tachycardia

Minimal variability

No contractions of significance

Maternal treatment with magnesium sulfate, which typically decreases baseline and variability—not increase it

NCC and AWHONN physiology guidelines emphasize that fetal tachycardia is most commonly associated with maternal infection, including chorioamnionitis, especially in preterm labor.

Magnesium sulfate does not cause tachycardia; it generally causes:

↓ baseline

↓ variability

Thus, fetal tachycardia + minimal variability in a preterm patient strongly suggests maternal infection, requiring evaluation for chorioamnionitis.

Why the wrong answers are incorrect:

A. Acetaminophen → used after confirming fever, not before evaluating the cause.

B. Discontinuing magnesium → magnesium sulfate does not cause tachycardia; discontinuing it removes fetal neuroprotection.

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

NICHD/NCC definitions:

Prolonged deceleration: decrease in FHR ≥15 bpm lasting 2 to 10 minutes

Bradycardia: baseline FHR <110 bpm lasting ≥10 minutes

The differentiating factor is duration, not rate and not contraction relationship.

Before 10 minutes → prolonged deceleration

At or beyond 10 minutes → new baseline → bradycardia

Thus, the factor that differentiates the two is length of time it lasts.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

NCC defines amnioinfusion as indicated for:

Recurrent variable decelerations caused by cord compression

Oligohydramnios reducing buffer around the cord

Expected effect:

Reduction or elimination of variable decelerations

Why the other answers are incorrect:

A. Variability does not improve with amnioinfusion.

B. Baseline FHR does not increase as a result of amnioinfusion.

Correct answer: C. Resolution of variable decelerations.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

NICHD/NCC criteria:

Category I must have ALL of the following:

Baseline 110–160 bpm

Moderate variability

No late or variable decelerations

Early decelerations may be present or absent

Accelerations may be present or absent

Because this tracing has one variable deceleration, it fails Category I criterion (“no late or variable decelerations”).

Category III requires:

Absent variability with recurrent late decels, recurrent variables, or bradycardia, or

Sinusoidal pattern

Those findings are not present.

Therefore, any tracing that:

Has moderate variability and accelerations,

But includes a variable deceleration, and

Does not meet Category III criteria

…falls into the Category II (indeterminate) group.

Correct classification: B. Category II.

Comprehensive and Detailed Explanation From NCC-Aligned BPP Management Standards:

NCC, AWHONN, and maternal-fetal medicine guidelines state:

A BPP score of 4/10 at term is abnormal.

A low score indicates hypoxia-related CNS suppression.

Oligohydramnios is an additional high-risk finding, especially in hypertension.

At ≥ 37 weeks, a BPP score of ≤ 4/10 warrants immediate delivery.

Repeating the test is acceptable at preterm gestations (e.g., < 32–34 weeks), but not at 38 weeks.

Why the other answers are incorrect:

B. Discharge home — Contraindicated with abnormal BPP.

C. Repeat in 24 hours — Not recommended at term with a score of 4.

Correct answer: A. Admit for delivery

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

Post-dates surveillance focuses on:

Amniotic fluid volume (AFI or deepest vertical pocket)

This is the most sensitive parameter of placental function

Oligohydramnios is strongly associated with post-maturity and perinatal morbidity

NCC and AWHONN emphasize amniotic fluid as the primary parameter for fetal well-being in post-term surveillance.

Why the incorrect answers are wrong:

B. Fetal weight → inaccurate and not used for surveillance decisions.

C. Placental calcification → poor predictor of fetal outcome and not used for management.

Comprehensive and Detailed Explanation From Exact Extract NCC-Recommended Sources

Oxygen saturation refers to the percentage of hemoglobin binding sites occupied by oxygen. NCC physiology resources, including Simpson & Creehan and Creasy & Resnik, define oxygen saturation as the “ratio of oxyhemoglobin to total hemoglobin”—the same definition used in fetal oxygenation discussions.

Oxygen affinity refers to hemoglobin’s tendency to bind oxygen (related to the oxyhemoglobin dissociation curve).

Oxygen carrying capacity refers to the total amount of oxygen hemoglobin can transport, independent of current saturation.

AWHONN and Menihan emphasize that fetal oxygenation assessment is dependent on understanding oxygen saturation, not affinity or carrying capacity, when discussing fetal hypoxemia and gas exchange.

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

Sustained fetal supraventricular tachycardia (SVT) often produces heart rates > 200–240 bpm, causing:

Poor ventricular filling

Decreased stroke volume

Reduced cardiac output

Congestive heart failure

Progressive fluid accumulation

NCC and AWHONN emphasize that untreated SVT leads to hydrops fetalis, characterized by:

Ascites

Pleural effusion

Pericardial effusion

Skin edema

Why the other answers are incorrect:

A. Fetal anemia — Causes tachycardia but is not caused by SVT.

C. Neonatal pacemaker — Pacemakers treat heart block, not SVT.

Correct answer: B. Hydrops fetalis

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

A wandering baseline is:

A slow, fluctuating baseline

Low amplitude

No variability

No accelerations

Indicative of severe fetal neurologic injury and terminal fetal status

NCC and AWHONN describe wandering baseline as a preterminal pattern.

Why the other answers are wrong:

A. Marked variability → often transient and not associated with demise.

B. Recurrent lates → concerning but not a neurological-injury pattern unless variability absent.

Correct answer: C. Wandering baseline.

Comprehensive and Detailed Explanation From Exact Extract (No URLs)

For fetuses before 32–34 weeks, the National Certification Corporation (NCC) follows the physiologic standards established by AWHONN, Simpson & Creehan, Menihan, and Creasy & Resnik, which emphasize that preterm fetuses have less mature autonomic nervous system development, resulting in smaller and shorter accelerations.

According to the NCC C-EFM Exam Content Outline (Pattern Recognition & Intervention) and the AWHONN Fetal Heart Monitoring Principles (2022–2024):

Preterm fetuses (<32 weeks) normally demonstrate 10 bpm × 10 sec accelerations.

By approximately 32–34 weeks, accelerations may begin transitioning toward 15×15, but the accepted standard for documentation at 34 weeks remains 10×10, unless clearly meeting 15×15 criteria.

NCC emphasizes using gestational-age–appropriate criteria for documenting accelerations, because autonomic reactivity increases gradually and is not fully comparable to term until after 32–34 weeks.

Menihan’s Electronic Fetal Monitoring also states that preterm fetuses “should be evaluated with the 10×10 rule until it is clear that the fetus is demonstrating mature 15×15 acceleratory capacity.”

Simpson & Creehan reinforce this point, noting that accelerations in late preterm gestations “may not consistently reach 15 bpm for 15 seconds, and thus 10×10 remains the appropriate designation.”

Since the patient is 34 weeks, the fetus is late-preterm and may not reliably meet the full 15×15 criteria; therefore, the correct documentation standard remains 10×10.

Thus, accelerations should be charted as:

“Present 10×10.”

References

NCC C-EFM Candidate Guide 2025 – Content Domain: Pattern Recognition and Intervention

AWHONN Fetal Heart Monitoring Principles & Practices, 2022–2024

Menihan: Electronic Fetal Monitoring: Concepts and Applications

Simpson & Creehan: Perinatal Nursing

Miller: Fetal Monitoring Pocket Guide

Creasy & Resnik: Maternal–Fetal Medicine

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.

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

A biophysical profile (BPP) assesses 5 components:

FHR reactivity

Fetal breathing movements

Fetal tone

Fetal movement

Amniotic fluid volume

According to NCC/AWHONN, fetal breathing movements are controlled by the fetal central nervous system, specifically brainstem integrity.

Thus, fetal breathing movements signify normal neurologic function, particularly intact CNS and oxygenation.

Why the others are incorrect:

Pulmonary vasoconstriction is not assessed by BPP.

Surfactant levels do not correlate directly with fetal breathing movement scores.

Correct answer: A. Neurologic function.

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

When internal monitoring continues to record artifact despite:

Changing the scalp electrode

Ensuring correct attachment

Checking cable connections

Confirming maternal movement is not the cause

NCC requires confirmation of fetal well-being using another modality.

The correct next step is direct auscultation with Doppler or fetoscope.

Why other answers are incorrect:

Oxygen is not indicated for equipment malfunction.

Repositioning does not resolve internal FHR artifact.

Thus, Auscultate the fetal heart rate is the appropriate next step.

Comprehensive and Detailed Explanation From Exact Extract (NCC-Referenced Sources)

According to the NCC C-EFM Exam Outline and AWHONN Fetal Heart Monitoring (5th & 6th ed.), recurrent variable decelerations with progressive reduction in variability reflect worsening fetal hypoxia, especially when coupled with prolonged second stage and arrest of descent.

AWHONN and Menihan both state that:

“Minimal variability with recurrent decelerations indicates inability of the fetus to maintain adequate oxygenation.”

“Failure of descent in second stage with non-reassuring patterns requires operative delivery.”

Creasy & Resnik emphasize that operative vaginal birth requires:

(1) fetal head at +2 station or below,

(2) favorable position,

(3) reassuring fetal status.

Here, the fetus is OP, descent has arrested, and FHR is non-reassuring. This contraindicates vacuum extraction.

Therefore, the appropriate management under NCC competencies is cesarean birth.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

NICHD Category II includes:

Minimal variability

Marked variability

Absent accelerations without recurrent decelerations

Indeterminate baseline characteristics

A tracing with no accelerations and no decelerations becomes Category II if paired with marked variability, because marked variability indicates potential stress.

Why other answers are wrong:

A. FHR 110 bpm → normal baseline if variability normal.

B. Sinusoidal pattern → Category III, not Category II.

Correct answer: Marked variability.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

NCC and AWHONN emphasize unit-wide shared responsibility for:

Recognizing abnormal maternal or fetal findings

Calling for help

Triggering emergency responses (e.g., unit huddle, rapid response, safety pathways)

Safety culture requires:

Any staff member (RN, tech, provider) to initiate an alarm or escalate concern

No hierarchy delay

Rapid action when fetal compromise is suspected

Why the other answers are wrong:

A. Determined by unit leaders → incorrect; safety is team-wide, not hierarchical.

C. Occur infrequently → false; alarms must occur whenever needed, not limited.

Correct answer: B. Can be called by anyone.

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

Accurate classification of decelerations requires evaluating their shape, onset, nadir, recovery, relationship to contractions, and variability characteristics. NCC uses the NICHD standardized definitions, reinforced across AWHONN, Miller’s Pocket Guide, Menihan, Simpson, and Creasy & Resnik.

Key features in this tracing:

Abrupt onsetThe FHR drops rapidly from baseline to nadir in less than 30 seconds—this is the defining hallmark of a variable deceleration per NICHD.

Sharp V-shape and deep amplitudeThe tracing shows steep descents and ascents, characteristic of cord compression–type variable decelerations.

Inconsistent timing with contractionsThe decelerations do not begin at the start of contractions (as early decelerations would) and do not consistently begin after the peak of contractions (as late decelerations would). Variable decelerations can occur before, during, or after a contraction—exactly what is demonstrated here.

Rapid return to baselineAnother core feature of variable decelerations in NICHD/NCC definitions.

No uniform contraction relationshipEarly decelerations are symmetrical and mirror contractions. Late decelerations begin after the peak of the contraction. This strip does not match either pattern.

Differentiation per NCC-aligned definitions:

Early Decelerations:Gradual onset (>30 sec), nadir mirrors contraction peak, shallow, uniform.Not present.

Late Decelerations:Gradual descent, nadir after contraction peak, smooth shape.Not present.

Variable Decelerations:Abrupt onset (<30 sec), variable timing, sharp V-shape, rapid recovery, often with shoulders.Exactly matches the tracing.

Therefore, according to NICHD/NCC criteria, the decelerations shown are variable decelerations.

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

NCC and AWHONN physiology teachings:

Variable decelerations caused by cord compression lead to:

Transient interruption of umbilical venous flow

Impaired fetal gas exchange

Acute rise in COâ‚‚

Respiratory acidosis (early phase of hypoxemia)

This is well documented:

Early decelerations → head compression → NOT associated with acidemia.

Late decelerations → uteroplacental insufficiency → metabolic acidosis, not respiratory.

Thus:

Variable decelerations → respiratory acidosis

Late decelerations → metabolic acidosis

Correct answer: C. Variable

Comprehensive and Detailed Explanation From Exact Extract (NCC-Recommended Sources Only)

The fetal heart rate (FHR) tracing shown demonstrates a baseline approximately 135–145 bpm with fluctuations of 6–25 bpm, a hallmark of moderate variability. Moderate variability is defined in all NCC-endorsed resources as the normal amplitude range of 6–25 bpm around the fetal baseline.

According to the AWHONN Fetal Heart Monitoring Principles & Practices (2022–2024), moderate variability is considered the single most reliable indicator of adequate fetal oxygenation and intact neurologic pathways, specifically reflecting well-functioning sympathetic and parasympathetic interplay.

The NICHD/NCC standardized definitions included in the NCC C-EFM Candidate Guide state:

Minimal variability: amplitude range ≤ 5 bpm

Moderate variability: amplitude range 6–25 bpm

Marked variability: amplitude > 25 bpm

Sinusoidal pattern: smooth, undulating waveform, 3–5 cycles per minute, equal amplitude, absent beat-to-beat variability

The tracing provided does not show the repetitive, smooth, wave-like pattern of a sinusoidal rhythm; nor does it show flattening associated with minimal variability. Instead, it includes continuous beat-to-beat fluctuation within the moderate range, without periods of absent or minimal variability.

Menihan’s Electronic Fetal Monitoring (5th ed.) and Simpson & Creehan’s Perinatal Nursing (5th ed.) both emphasize that moderate variability is:

A reassuring feature

Indicative of adequate fetal CNS oxygenation

Expected in a reactive, well-oxygenated fetus

A key criterion for Category I classification

Additionally, Miller’s EFM Pocket Guide reiterates that variability between 6–25 bpm is considered the normal (moderate) fetal autonomic response and is not a sinusoidal pattern, which has a fixed amplitude and frequency.

Therefore, based on NCC-standard definitions and the observed amplitude, the correct interpretation is moderate variability.

References (No URLs):

AWHONN Fetal Heart Monitoring Principles & Practices; NCC C-EFM Candidate Guide 2025; Simpson & Creehan Perinatal Nursing; Menihan Electronic Fetal Monitoring; Miller’s Pocket Guide to Fetal Monitoring; Creasy & Resnik Maternal-Fetal Medicine.

Comprehensive and Detailed Explanation From Exact Extract Without Links:

According to the NCC C-EFM Content Outline and AWHONN Fetal Heart Monitoring Principles, recurrent decelerations are specifically defined as decelerations that occur with ≥50% of uterine contractions in a 20–30-minute window, but standardized interpretation guidelines used by NCC and ACOG categorize recurrent patterns based on any 30-minute evaluation period.

AWHONN (FHM 6th Ed.) explains that fetal heart patterns must be evaluated over “a sufficiently long segment, typically 30 minutes, to determine whether the pattern is intermittent or recurrent.”

Menihan & Simpson further emphasize that recurrent decelerations imply a persistent physiologic stressor, requiring systematic evaluation and intrauterine resuscitation. NCC's Candidate Guide ties this rule directly into categorization within Category II and III tracings. Therefore, 30 minutes is the correct standard evaluation interval for determining recurrence.

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Comprehensive and Detailed Explanation From Exact Extract NCC-Recommended Sources

Variability is created by beat-to-beat differences in fetal cardiac intervals due to autonomic nervous system modulation. AWHONN specifies that absent variability appears as “a near-straight line with minimal or no discernible oscillations,” which occurs when all beat intervals are identical.

Menihan notes that Doppler displays variability based on mechanical motion and will show flat, unchanging intervals when fetal autonomic modulation is suppressed, reflecting absent variability.

Bradycardia refers to a baseline <110 bpm and does not describe the uniformity of intervals. A normal baseline may still show variability; it cannot have identical beat-to-beat intervals, as this violates the definition of variability in NICHD terminology.

Simpson & Creehan state that absent variability is a significant marker of impaired fetal oxygenation or CNS depression.

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:

The fetal heart rate tracing demonstrates recurrent deep variable decelerations with a rapid drop in FHR, a V-shaped pattern, and slow return to baseline. These are classic signs of cord compression. According to NCC, AWHONN, Miller, Menihan, and Simpson, recurrent variable decelerations require immediate intrauterine resuscitative interventions before any decision regarding operative birth.

NCC-aligned intervention steps include:

Maternal repositioning (first-line for cord compression)

Reducing or stopping oxytocin if infusing

IV fluid bolus

Amnioinfusion (if appropriate and recurrent deep variables persist)

Oxygen only if other measures fail (per NCC/AWHONN updated guidance)

The cervix has remained unchanged at 5 cm for 3 hours (a prolonged latent or early active labor pattern), but the fetal tracing shows Category II—recurrent variable decelerations. Category II dictates corrective action, not immediate delivery unless it progresses to Category III.

Cesarean birth (option C) is reserved for:

Persistent Category III

Failure of intrauterine resuscitation

Proven fetal intoleranceNone of these conditions have been met yet.

Thus, the correct initial management is B. Perform intrauterine resuscitative measures.

Comprehensive and Detailed Explanation From NCC-Aligned Sources:

The black tracing (Baby A) demonstrates:

Baseline ~170–175 bpm

Moderate variability

No recurrent decelerations

This is fetal tachycardia.

NCC physiology guidelines list common causes of fetal tachycardia:

Maternal fever / infection (chorioamnionitis)

Maternal dehydration

Maternal anxiety

Maternal hyperthyroidism

Fetal infection

Certain medications (terbutaline, illicit stimulants)

Why the other options are incorrect:

A. Fetal positioning does not influence baseline heart rate.

C. Magnesium sulfate typically lowers fetal baseline and variability—it does not cause tachycardia.

Thus, the most likely etiology is infection.