Comprehensive and Detailed Explanation From NCC-Aligned Sources:
A prolonged deceleration is defined by NICHD and NCC as:
A deceleration lasting ≥2 minutes but <10 minutes
Decrease in FHR of ≥15 bpm
Can occur with or without uterine contractions
This tracing shows:
A deep drop in FHR down to ~60–70 bpm
Duration lasting several minutes
Recovery back to baseline
Moderate variability present afterward
Because variability remains present and the tracing does not show:
Absent variability
Recurrent late decelerations
Recurrent variable decelerations with absent variability
Bradycardia for ≥10 minutes
…it does not meet criteria for Category III.
It is also not bradycardia, because bradycardia requires:
Therefore the correct interpretation is a prolonged deceleration.
[References:NCC C-EFM Candidate Guide; NICHD FHR Definitions; AWHONN FHMPP; Menihan; Simpson & Creehan.]