What are atypical decelerations?
The “atypical variable deceleration” presents a different set of characteristics from those normally seen as a result of baroceptor response. There may be a “W,” “U,” or a widened “V”-shape to the deceleration pattern (Figures 2 and 3).
What is a deceleration on a CTG?
Decelerations are transient episodes of decrease of FHR below the baseline of more than 15 bpm lasting at least 15 seconds.
What are the types of decelerations?
There are three basic types of decelerations: early decelerations, late decelerations, and variable decelerations. Early decelerations are generally normal and not concerning. Late and variable decelerations can sometimes be a sign the baby isn’t doing well.
How do you interpret CTG variability?
Normal variability indicates an intact neurological system in the fetus. Normal variability is between 5-25 bpm. To calculate variability you need to assess how much the peaks and troughs of the heart rate deviate from the baseline rate (in bpm).
What does minimal variability mean?
Minimal = < 5 BPM. Moderate = 6 to 25 BPM. Marked = > 25 BPM. The tracing to the right shows an amplitude range of ~ 10 BPM (moderate variability ).
What is prolonged deceleration?
Prolonged deceleration. A decrease in FHR below the baseline of 15 bpm or more, lasting at least 2 minutes but <10 minutes from onset to return to baseline. A prolonged deceleration of 10 minutes or more is considered a change in baseline.
Can you have a decel without a contraction?
Spontaneous single decelerations in absence of uterine contractions, are infrequent situations. Most international reports describe single pregnancy cases. The etiology of this severe spontaneous deceleration in the absence of uterine contractions is unknown.
What causes a prolonged deceleration?
Prolonged decelerations can be caused by any mechanism which normally may lead to periodic or episodic decelerations, but the return to baseline is delayed because the stimulus or mechanism causing the deceleration is not reversed. This often is associated with hypoxia.
What is a prolonged deceleration?
What is the normal range of CTG baseline?
5.5. 1 FHR parameters and assessment criteria (Table 3)
| Parameter | Baseline rate (bpm) | Range (bpm) |
|---|---|---|
| Normal | 110–160 | ≥ 5 |
| Suspicious | 100–109161–180 | < 5 ≥ 40 minutes> 25 |
| Pathological | < 100> 180sinusoidal3 | < 5 > 90 minutes |
What does a late deceleration mean?
Late deceleration is defined as a visually apparent, gradual decrease in the fetal heart rate typically following the uterine contraction. The gradual decrease is defined as, from onset to nadir taking 30 seconds or more.
What do prolonged decelerations look like?
Prolonged deceleration: a visually apparent decrease of 15 or more beats per minute below the baseline. This decrease lasts at least 2 minutes but less than 10 minutes from onset to the return to baseline (≥10 minutes is con- sidered a baseline change).
What are complicated variable decelerations in a CTG?
‘complicated’. Complicated variable decelerations are defined by their features as well as the other features of the CTG. These additional features indicate the likelihood of fetal hypoxia and the definition includes one or more of the following: o Rising baseline rate or fetal tachycardia o Reduced or absent baseline variability
How common are atypical variable decelerations in neonates?
Admission to the neonatal intensive care unit was more common in patients with atypical variable decelerations in comparison with typical variable decelerations (34.3% versus 3.1%). Conclusion: While typical variable decelerations are frequently harmless, atypical variations pose a significant risk of fetal hypoxia.
What does it mean when there are no accelerations in CTG?
Accelerations occurring alongside uterine contractions is a sign of a healthy fetus. The absence of accelerations with an otherwise normal CTG is of uncertain significance.
What are atypical decelerations during pregnancy?
Those variable decelerations are known as atypical decelerations. A decline of the fetal HR till 70 b/min and duration of decelerations for ≥ 60 min confirm a suspicion about fetal reserves and well- tolerated labor. CTG during pregnancy. CTG during pregnancy refers to the performance of the non-stress-test (NST).