Which of the following is a sign of potential fetal distress?

Prolonged late decelerations in fetal heart rate monitoring are a clear indication of potential fetal distress. Late decelerations are defined as a decrease in the fetal heart rate that begins after a contraction starts and does not return to the baseline heart rate until after the contraction is over. This pattern suggests that there may be an issue with placental perfusion, indicating that the fetus is not receiving enough oxygen. When late decelerations are prolonged, it raises the concern for a significant compromise in the fetal condition, which may require immediate medical intervention to ensure the safety and health of the fetus.

In contrast, a normal baseline fetal heart rate indicates that the fetus is generally healthy and not in distress. Frequent accelerations in heart rate are a reassuring sign that the fetus is responding well to stimuli and is typically indicative of good fetal oxygenation. While head compression during contractions may lead to early decelerations, these are usually not alarming as they typically resolve quickly and are considered a normal physiological response to labor. Therefore, the presence of prolonged late decelerations is the key indicator of possible fetal distress among the options provided.