Dolphin Sign in NST
The provided evidence does not contain any information about a "dolphin sign" on non-stress testing. This term does not appear in the ACR Appropriateness Criteria guidelines for fetal well-being assessment 1 or in the research literature on NST interpretation 2, 3, 4, 5, 6.
What the Evidence Does Cover About NST Interpretation
The guidelines focus on standard NST criteria 1:
- Reactive NST: Two or more fetal heart rate accelerations during 20 minutes of observation
- Non-reactive NST: After 40 minutes, one or no acceleration detected
- Acceleration definition (≥32 weeks): 15 beats/minute above baseline lasting 15 seconds
- Acceleration definition (<32 weeks): 10 beats/minute above baseline lasting 10 seconds
Alternative NST Findings Discussed
The evidence addresses several NST patterns:
- Single sporadic decelerations: Drops of ≥40 bpm below baseline lasting ≥2 minutes, which when followed by reactive NST are generally reassuring 5
- Moderate variability: Recent evidence suggests moderate variability alone may be sufficient for reassurance even without accelerations 6
- Acoustic stimulation response: Can help differentiate true non-reactive from false non-reactive NSTs 4
Clinical Recommendation
If you encountered the term "dolphin sign" in clinical practice, clarify its definition with the source, as this is not standard obstetric terminology recognized in current guidelines or peer-reviewed literature. Continue using established NST interpretation criteria as outlined above for clinical decision-making regarding fetal well-being 1.