|
|
|
Evaluations: Normal – 120
160 bpm. Variability is the change from baseline that occurs over
seconds or minutes (the wiggles)
|
|
|
|
Abnormal variations are >
160 bpm (tachycardia) or < 120 bpm (bradycardia). Tachycardia is
considered (sustained rate of 161 bpm
) ominous if accompanied by late
decelerations, severe variable decels, or ↓ variability. Bradycardia
with rate < 110 – 120 bpm during a 10 min period can be ominous or
benign. When accompanied by late decels, considered a sign of fetal distress.
|
|
|
|
Accelerations: the
transient ↑ in FHR normally caused by fetal movement. In response to
contractions, considered a good sign.
|
|
|
|
Decelerations:
periodic decreases in FHR from norm baseline. Categorized as early, late, and variable.
|
|
Early - Fetal head is compressed → central
vagal stimulation → early deceleration. Onset is before onset of
uterine contraction, considered benign.
|
|
|
|
Late – caused by
uteroplacental insufficiency d/t dec blood flow & O2 to fetus during contraction. Occurs after onset of contractions.
Considered non-reassuring, but not necessarily eminent for childbirth.
|
|
|
|
Variable – umbilical
cord is compressed, ↓ blood flow between placenta & fetus. Needs
further assessment.
|
|
Look on pate 349, Figure 16
– 11.
|