Fetal heart monitoring heart rate is too high for a number of reasons, can be broadly divided into maternal factors and fetal factors, the following are the more common reasons: First, maternal factors: when the mother fever, tachycardia will cause the fetal heart rate faster, in addition, the mother has hyperthyroidism, acute chorionic amnioamnionitis, and other diseases, or taking some of the drugs to make the heart rate faster, the fetal heart rate will follow the accelerated. Fetal factors: 1, fetal movement or contraction: fetal movement or contraction, the fetal heart rate will be a transient increase. If it only occurs occasionally, it is generally normal; 2, hypoxia: when the umbilical cord pressure, amniotic fluid is too small, it will lead to fetal hypoxia in the uterine cavity, hypoxia in the early stage will lead to an increase in the fetal heart rate; 3, cardiac rhythm abnormality: if the fetus itself has an abnormal cardiac rhythm, tachycardia, it will also lead to a rapid fetal heart rate.