Fetal heartbeat cannot identify the character of the fetus. Fetal heartbeat is the heartbeat of the fetus, which reflects the state of the fetus in the womb. Fetal sex determination for non-medical purposes is illegal in China. Fetal heartbeat is mainly used to reflect the condition of the fetus. When pregnant women are in their fourth month of pregnancy, they can hear the fetal heartbeat near the midline under the umbilicus through a stethoscope. The speed of the fetal heart does not have any relationship with the character of the fetus. It is usually used to reflect the intrauterine reserve of the fetus, and once there is a lack of oxygen, abnormalities of the fetal heart are likely to occur. Electronic fetal heart rate monitoring (EFHM) is an important tool for monitoring and evaluating the intrauterine safety and well-being of the fetus in the late stages of pregnancy, especially near term, and during labor. Fetal heart rate has nothing to do with sex. The sex of the fetus is determined by the sex chromosomes, which are already determined at the time of sperm-egg union, and does not change according to the fetal heart rate.