Types of Decelerations Flashcards
(13 cards)
What are decelerations in fetal heart rate?
Short term decrease in heart rate at least 15 bpm below baseline, lasting for at least 15 seconds.
How many types of decelerations can only be diagnosed with Electronic Fetal Monitoring (EFM)?
Four types.
What does an early deceleration typically (not always) reflect?
Normal response to fetal descent, especially at low stations.
What are the criteria for early decelerations?
- Onset/recovery: Gradual (30 seconds)
- Shape: Mimics contraction
- Nadir: same as zenith of the contraction
- Depth: Minimum of 90 bpm.
True or False: Early decelerations always indicate head compression.
False.
What are late decelerations indicative of?
Utero-placental insufficiency.
What are the criteria for late decelerations?
- Onset/recovery: gradual (30 seconds)
- Shape: Delayed mimic of contraction
- Nadir of decel: occurs after peak of contraction
- Depth: of 90 bpm
What do late decelerations strongly indicate?
Fetal acidosis.
What causes variable decelerations?
Cord compression (prolapse, nuchal, knot).
What are the criteria for variable decelerations?
- Recovery/onset: Abrupt (less than 30 sec)
- Can occur at any point
- Depth: Usually below 90 bpm & as low as 60 bpm
What are prolonged decelerations associated with?
- Maternal hypotension
- Uterine rupture
- Seizure
- Rapid descent
- Coached pushing
- Severe cord compression.
What is the duration of prolonged decelerations?
> 2 minutes but less than 10 minutes (often 2-3 minutes).
What is the difference between recurrent and intermittent decelerations?
Recurrent decelerations occur repeatedly, while intermittent decelerations do not.
