Fetal sound is also known as fetal heart sound, fetal heart monitor can usually hear the fetal heart sound at 12 weeks. Fetal heart monitor is also known as fetal ultrasound Doppler monitor, generally 12 weeks pregnant through the monitoring can hear the fetal heart sound, the normal fetal heart should be in 110-160 beats / min, 18-22 weeks pregnant will appear fetal movement, fetal heart sound is also more obvious, 30-32 weeks pregnant can be done after the fetal heart monitor, to understand the development of the fetus in the womb whether the situation is abnormal. Some women choose to monitor the fetal heart at home with a home fetal heart monitor. When monitoring at home, pregnant women are unfamiliar with the knowledge of monitoring the fetal heart, and may not be able to find the fetal heart or may take some of the umbilical arterial blood flow as the normal fetal heart value, which will result in an error in the examination. After pregnancy to do a good job of pregnancy checkups, through the fetal heart rate can also be able to understand the development of the fetus in the womb is abnormal, if there are symptoms of physical discomfort, you should go to the hospital in a timely manner, consult the physician’s guidance.