Which characteristic is associated with tachycardia in fetal heart rate monitoring?

Tachycardia in fetal heart rate monitoring is characterized by an increased heart rate, typically defined as a baseline heart rate greater than 160 beats per minute. When assessing fetal heart rate patterns, a decrease in variability is often observed alongside tachycardia. Decreased variability reflects less fluctuation in the heart rate, which may indicate that the fetus is under some level of stress or experiencing a physiological response, potentially due to factors such as maternal fever, infection, or fetal hypoxia.

Increased variability is generally associated with fetal well-being and can indicate a reactive or healthy fetal condition, while consistent or no variability suggests a lack of normal responses in the fetal heart rate, which could signal a distressed state. Therefore, decreased variability aligns with the physiological response to tachycardia, making it the correct answer in this context.