Which type of decelerations occur with fewer than 50% of contractions during a 20 minute period?

Intermittent decelerations are characterized by their occurrence with fewer than 50% of contractions within a specified time frame, such as a 20-minute period. This classification denotes that these decelerations are not consistently associated with contractions, thereby differentiating them from other types that occur more regularly or continuously.

For instance, recurrent decelerations happen with at least 50% of contractions and suggest a more enduring fetal response to stress during labor. Conversely, episodic decelerations are independent of uterine contractions and can be temporarily seen during certain activities or events, indicating a sporadic pattern. Variable decelerations can occur at any time, often in response to umbilical cord compression, but may also include elements of recurrence or intermittence based on their frequency and duration.

Overall, intermittent decelerations signal a more sporadic pattern of fetal heart rate change in relation to contractions, making this classification essential for understanding fetal well-being during labor.