Free tool · Scored assessment · L&D
Fetal Heart Rate Category Interpreter.
Read the strip into the NICHD three-tier system — Category I, II, or III. Enter the five features that define a tracing: baseline rate, baseline variability, accelerations, decelerations, and whether a sinusoidal pattern is present. You get the category, what it predicts about fetal acid–base status, and the usual management framing. Nomenclature and categories follow the 2008 NICHD workshop and ACOG intrapartum monitoring guidance. The category supports your team’s judgment — it never replaces provider evaluation of the live tracing.
Describe the tracing
Use a representative window (commonly ~10 minutes). Decelerations are “recurrent” when they occur with ≥50% of contractions, “intermittent” when <50%.
Describe all features to see the NICHD category.
NICHD three-tier categories [1][2]
| Category | Defined by | Predicts |
|---|---|---|
| I — Normal | ALL of: baseline 110–160; moderate variability; late & variable decels absent; early decels present or absent; accels present or absent | Strongly predictive of normal fetal acid–base status at the time observed |
| II — Indeterminate | Any tracing that is not Category I or III (e.g., tachycardia, minimal/absent variability without recurrent decels, recurrent variables with moderate variability, prolonged decel, intermittent decels) | Not predictive of abnormal acid–base status, but warrants evaluation and continued surveillance |
| III — Abnormal | EITHER absent variability WITH recurrent late decels, recurrent variable decels, or bradycardia — OR a sinusoidal pattern | Predictive of abnormal fetal acid–base status at the time observed; requires prompt action |
“Recurrent” = occurring with ≥50% of contractions in a 20-minute window; “intermittent” = <50%. Note that for Category III, absent variability is required alongside the recurrent late, recurrent variable, or bradycardia — the same decelerations with moderate variability are Category II, not III (a sinusoidal pattern is Category III on its own). Categories describe the tracing at the time observed and can change — reassess continuously. Your provider and unit protocol drive management of the live tracing.
References
- Macones GA, Hankins GDV, Spong CY, Hauth J, Moore T. The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines. Obstet Gynecol. 2008;112(3):661–666. PMID: 18757666. (Standardized FHR definitions and the three-tier classification system.)
- American College of Obstetricians and Gynecologists (ACOG). Practice Bulletin No. 106: Intrapartum fetal heart rate monitoring — nomenclature, interpretation, and general management principles (reaffirmed; see also PB No. 116). acog.org. (Adoption of NICHD nomenclature and category-based management.)
- Intrauterine resuscitation measures (repositioning, IV fluid, reducing uterotonics, treating hypotension, supplemental oxygen when indicated) summarized from ACOG intrapartum monitoring guidance and standard obstetric references.
Category definitions and feature thresholds were transcribed from the NICHD 2008 report and ACOG guidance. Management of the live tracing is individualized by the care team.
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