Reference — Maternal-Newborn
Fetal Heart Rate Patterns
Fetal heart rate monitoring is a core intrapartum assessment skill. This reference covers the NICHD standardized terminology for baseline rate, variability, accelerations, and all three deceleration patterns — with clinical significance and nursing responses for each.
Educational use only. FHR interpretation and management require current AWHONN/ACOG training. Abnormal patterns must be communicated to the provider immediately. Always follow institutional EFM protocols and AWHONN guidelines. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
NICHD Three-Tier Classification
Baseline Fetal Heart Rate
Baseline FHR is the mean rate rounded to the nearest 5 bpm during a 10-minute window, excluding accelerations, decelerations, and periods of marked variability. Requires at least 2 minutes of identifiable baseline.
Baseline Variability
| Category | Amplitude | Clinical Significance |
|---|---|---|
| Absent | Undetectable | Associated with significant hypoxia; Category III if with late/variable decels |
| Minimal | >0 but ≤5 bpm | May reflect sleep cycle, opioids, magnesium; or fetal compromise — evaluate context |
| Moderate | 6–25 bpm | Normal — most reliable indicator of adequate fetal oxygenation |
| Marked | >25 bpm | Cause unclear; evaluate for hypoxia, cord compression |
Moderate variability (6–25 bpm) is the single most reassuring FHR finding — it indicates an intact neurologic pathway.
Accelerations
An abrupt increase in FHR above baseline. At ≥32 weeks: peak ≥15 bpm above baseline, lasting ≥15 seconds but <2 minutes. Before 32 weeks: peak ≥10 bpm, lasting ≥10 seconds.
Clinical significance:
Accelerations are reassuring — they indicate a reactive fetus with intact autonomic nervous system. Two or more accelerations in 20 minutes = reactive nonstress test (NST).
Nursing response:
- Document as reassuring; no intervention required
- Absence of accelerations over 40 minutes despite stimulation is non-reactive — notify provider
Early Decelerations
Gradual decrease in FHR (onset to nadir >30 seconds) that mirrors the shape of the contraction; nadir coincides with the peak of contraction.
Nursing response:
Document; continue routine monitoring; no intervention required. Early decelerations are normal in active labor.
Variable Decelerations
Abrupt decrease in FHR (onset to nadir <30 seconds) of ≥15 bpm below baseline, lasting ≥15 seconds but <2 minutes. Vary in shape, timing, and relationship to contractions.
Features of severe variable decelerations:
- Nadir <70 bpm
- Duration >60 seconds
- Slow return to baseline
- Loss of shoulders (brief accelerations before/after normal decel)
- Overshoot tachycardia following
Nursing response:
- Position change (left lateral, knee-chest)
- IV fluid bolus
- Oxygen 10 L/min via non-rebreather mask
- Notify provider if persistent or severe
- Amnioinfusion may be ordered for cord compression
Late Decelerations
Gradual decrease in FHR (onset to nadir >30 seconds) with nadir occurring after the peak of the contraction and returning to baseline after the contraction ends. Offset mirrors onset timing.
Nursing response (STOP action mnemonic):
- Stop oxytocin if infusing
- Turn patient left lateral decubitus
- Oxygen 10 L/min via non-rebreather mask
- Provider notification — immediate
- IV fluid bolus; prepare for potential urgent delivery
Prolonged Decelerations
A decrease in FHR of ≥15 bpm below baseline lasting ≥2 minutes but <10 minutes. A deceleration lasting ≥10 minutes is a baseline change.
Causes include cord prolapse, maternal hypotension (supine position, regional anesthesia), uterine hyperstimulation, or placental abruption. Requires immediate intervention and provider notification.
Related Resources
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with American College of Obstetricians and Gynecologists (ACOG) · AWHONN · American Academy of Pediatrics (AAP) — newborn. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →