What indicates a category III fetal heart rate pattern?

The indication of a category III fetal heart rate pattern is represented by absent variability combined with recurrent late decelerations. This classification is crucial for assessing the fetal condition during labor and delivery. A category III pattern is associated with an increased risk of fetal hypoxia or acidemia and necessitates immediate clinical attention.

Absent variability signifies that there is no fluctuation in the fetal heart rate, suggesting that the fetus may not be responding appropriately to stimuli, which could indicate distress. Additionally, recurrent late decelerations, which are dips in the fetal heart rate that begin after the contraction has started and return to baseline after the contraction ends, further imply that there is a concerning potential for inadequate oxygenation during labor.

In contrast, moderate variability with accelerations showcases a reassuring fetal status, while normal heart rate with variable decelerations may indicate a less concerning scenario that often resolves without intervention. A baseline heart rate within the normal range of 110-160 bpm, while important for overall assessment, does not on its own indicate a category III pattern. Therefore, the combination of absent variability and recurrent late decelerations is the defining characteristic of a category III fetal heart rate pattern.