variable deceleration
Fetal heart rate pattern indicating umbilical cord compression during contractions.
Full Definition
Variable decelerations are abrupt decreases in fetal heart rate that vary in timing, duration, and magnitude in relation to uterine contractions, typically caused by umbilical cord compression. These decelerations are characterized by their variable relationship to contractions and their sharp, angular appearance on fetal monitoring strips. They may occur before, during, or after contractions and can vary significantly from one contraction to the next. Mild variable decelerations are common and generally benign, but severe variables (lasting longer than 60 seconds, dropping below 70 beats per minute, or showing slow recovery) may indicate significant cord compression and potential fetal compromise requiring intervention.
Usage
Usage note: Often shortened to 'variables' in clinical discussion; distinguish from other deceleration types.
In Context
- "The fetal heart rate tracing showed moderate variable decelerations with good baseline variability and accelerations." — Fetal monitoring interpretation
- "Severe variable decelerations prompted position changes and consideration of amnioinfusion for cord compression relief." — Labor and delivery note