INtrapartum Fetal Monitoring Flashcards
The false-positive rate for electronic FHR monitoring for predicting CP is_____
> 99%.
The mean FHR rounded to increments of 5 beats/min during a 10-minute segment. Normal FHR baseline: ______
110–160 beats/minute
Non-hypoxic explanations include of tachycardia (maternal factors)
medications (β-adrenergic agonists [terbutaline], atropine, scopolamine), fever, thyrotoxicosis
Non-hypoxic explanations include of tachycardia (fetal factors)
repetitive accelerations (from fetal movements), fetal tachyarrythmias, prematurity
Bradycardia: FHR baseline is <110 beats/min
Non-hypoxic explanations include(maternal factors)
β-adrenergic blockers, local anesthetics
Bradycardia: FHR baseline is <110 beats/min
Non-hypoxic explanations include(fetal factors)
congenital heart block (associated with maternal lupus)
Fluctuations in the baseline FHR that are irregular in amplitude and frequency. It is a reflection of the autonomic interplay between the sympathetic and parasympathetic
nervous system.
Baseline variability:
Baseline variability:
- Absent amplitude range undetectable
- Minimal amplitude range detectable but ____
- Moderate (normal): amplitude range ____
- Marked: amplitude range_____
<5 beats/min
6-25 beats/min
> 25 beats/min
A visually apparent abrupt increase (onset to peak in <30 seconds) in the FHR.
These are mediated by the sympathetic nervous system in response to fetal movements or scalp stimulation
Acceleration
Normal acceleration
At ≥32 weeks gestation, an acceleration has
a peak of >15 beats/min above baseline,
with a duration of >15 seconds but < 2 min from onset to return
Normal acceleration
At <32 weeks gestation,
an acceleration has a peak of >10 beats/min above baseline,
with a duration of >10 sec but <2 min from onset to return
A visually apparent usually symmetrical gradual decrease and return of
the FHR associated with a uterine contraction
Early deceleration:
Significance of Early deceleration:
These are mediated by parasympathetic stimulation and occur in response to head compression.
Importance of late decel
These are mediated by either vagal stimulation or myocardial depression and occur in response to placental insufficiency
What deceleration?
The nadir of the deceleration occurs at the same time as the peak of the contraction
Early deceleration
What deceleration?
The deceleration is delayed in timing, with the nadir of the deceleration occurring
after the peak of the contraction.
Late deceleration
A visually apparent abrupt decrease in FHR. These are mediated by umbilical cord compression
Variable deceleration
It is important to recognize that FHR tracing patterns provide information only on the current acid–base status
of the fetus.
FHR tracing
Cat 1 tracing for FHR
- Baseline rate: 110-160 beats/min
- Baseline FHR variability: moderate
- Late or variable decelerations: absent
- Early decelerations: present or absent
- Accelerations: present or absent
These include all FHR tracings not categorized as category I or III, and may represent an appreciable fraction of those encountered in clinical care
Cat II
Mx of Cat II
evaluation and continued surveillance and reevaluation, taking into account the
entire associated clinical circumstances
What category?
- Recurrent late decelerations
- Recurrent variable decelerations
- Bradycardia
- Sinusoidal pattern
Category III: FHR tracings are abnormal
Mx of Cat III
expeditious intrauterine resuscitation to resolve the abnormal FHR pattern; if
tracing does not resolve with these measures, prompt delivery should take place
Variable Decelerations significance
umbilical cord compression
