Master the board step 3

Master the Boards: USMLE Step 3
Early Decelerations — head compression
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Variable decelerations: Abrupt decreases in FHR that are unrelated to contractions.
These are related to umbilical cord compression. Severe variables
are nonreassuring and indicate fetal acidosis.
Variable Decelerations — umbilical cord compression
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Late decelerations are gradual decreases in FHR and delayed in relation
to contractions. These are related to uteroplacental insufficiency. All late
decelerations are nonreassuring and indicate fetal acidosis.
Late Decelerations — uteroplacental insufficiency
· · Variability: Beat-to-beat fetal heart rate normally has variability. Normal
variability is 6–25 beats/minute. Absence of variability is a nonreassuring
pattern.
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