In early pregnancy, you cannot feel the fetal heart with your hands, but you can detect it with ultrasound or a fetal heart monitor. In late pregnancy, in addition to ultrasound and fetal heart rate monitoring, doctors can also listen to the fetal heartbeat with a stethoscope. Fetal heart, i.e. the heartbeat of the fetus, can reflect the state of the fetus in the uterus, and will be sensitive to changes when the fetus is deprived of oxygen for various reasons. The normal fetal heart rate is 110-160 beats per minute. The normal fetal heart rate changes from moment to moment depending on the intrauterine environment. Changes in fetal heart rate are a sign of normal regulation of the central nervous system and a sign that the fetus is in good condition in the uterus. If the fetal heart rate is >160 beats/minute and lasts for more than 10 minutes, it is called fetal tachycardia. If the fetal heart rate is less than 110 beats per minute for more than 10 minutes, it is called bradycardia. In most cases, an abnormal fetal heartbeat means that the fetus is suffering from oxygen deprivation in the uterus, and the more severe the fetal heartbeat abnormality, the more severe the oxygen deprivation is. If a pregnant woman monitors her fetal heartbeat at home and an abnormality occurs, she should seek prompt medical attention for examination and treatment.