Examkin

Question

Difficulty: EasyLabor, Delivery, and Puerperium

Match each intrapartum fetal heart rate pattern to its most likely underlying physiological etiology.

  • Early decelerationFetal head compression
  • Late decelerationUteroplacental insufficiency
  • Variable decelerationUmbilical cord compression
  • Sinusoidal patternSevere fetal anemia

Answer

Early deceleration corresponds to fetal head compression, late deceleration to uteroplacental insufficiency, variable deceleration to umbilical cord compression, and sinusoidal pattern to severe fetal anemia.
Each fetal heart rate pattern is tightly linked to a specific pathophysiological event. The 'VEAL CHOP' mnemonic correctly maps these relationships: Variable decelerations to Cord compression, Early decelerations to Head compression, Accelerations to Okay (normal oxygenation), and Late decelerations to Placental insufficiency. Additionally, a sinusoidal pattern uniquely indicates severe fetal anemia.

Step-by-Step Solution

1
Identify the underlying cause of early decelerations.
Early decelerations map to fetal head compression.
Head compression during a uterine contraction increases vagal tone, causing a benign, symmetric drop in fetal heart rate that mirrors the contraction.
2
Identify the underlying cause of late decelerations.
Late decelerations map to uteroplacental insufficiency.
Decreased oxygen delivery to the fetus during a contraction leads to a delayed heart rate drop that begins after the contraction peaks.
3
Identify the underlying cause of variable decelerations.
Variable decelerations map to umbilical cord compression.
Compression of the umbilical cord (e.g., from oligohydramnios or cord prolapse) causes an abrupt increase in fetal blood pressure, triggering a baroreceptor-mediated abrupt drop in heart rate.
4
Identify the underlying cause of a sinusoidal fetal heart rate pattern.
A sinusoidal pattern maps to severe fetal anemia.
Severe hypoxia or anemia (e.g., from vasa previa, alloimmunization) abolishes normal autonomic control, resulting in a smooth, undulating baseline.

Key Concept

Fetal heart rate monitoring patterns and their underlying etiologies
Estimated Time:45s
Rate this question

Topics

Labor, Delivery, and Puerperium

More questions from this topic