Which factor may lead to fetal tachycardia?

Maternal hyperthermia is an important factor that can lead to fetal tachycardia. When a mother experiences an elevated body temperature, it can result in increased fetal heart rate as the fetus responds to stressors in the environment. Hyperthermia can trigger a physiological response from the fetus, including increased heart rate, as it attempts to maintain homeostasis under the altered conditions.

In cases of maternal hyperthermia, the increased temperature may be due to various factors such as infection, overheating from environmental factors or fever. Elevated body temperature can affect the fetus's metabolic rate and oxygen consumption, leading to an increased heart rate as the body tries to compensate for any potential stress.

Other factors such as maternal anemia and fetal sleep cycles may influence fetal heart rate patterns, but they typically do not lead to sustained tachycardia in the same manner that maternal hyperthermia does. Similarly, decreased uterine contractions may not directly correlate with an increase in fetal heart rate as seen in the context of hyperthermia.