The way of listening to the fetal heart sound, with gestational weeks and instruments, is one of the important indicators to determine the state of the fetus in the uterus, there are usually the following methods: 1, 14-16 weeks of gestation: due to the deeper location of the gestational sac, the fetal heart rate is not obvious enough, so more use of Doppler stethoscope to detect the fetal heart sound, in addition to the fetal heart sound can be detected in addition to the blood flow, is an important basis for the evaluation of early fetal development; 2, 18-20 weeks of gestation Weeks: Because most of the fetal structures are located in the abdominal cavity at this time, with a general stethoscope through the abdominal wall of the pregnant woman can also hear fetal heart sounds, two-tone, similar to the clock ticking, faster, when the stethoscope is located on the back of the fetus sound clearer, can be differentiated from the pregnant woman’s heart rate, uterine murmur, abdominal aortic sounds, etc.; 3, after 32 weeks of gestation: the late stages of pregnancy can be listened to the fetal heart sounds through fetal heart monitoring, especially when the amniotic fluid is more sufficient, the fetal heart sounds in the umbilicus of pregnant women can be heard through fetal heart monitoring, especially in the case of amniotic fluid. When, in pregnant women navel of the right and left sides of the abdominal wall can be heard clearer fetal heart sound, fetal heart normal indicates that fetal development is good. When listening to the fetal heartbeat, it is necessary to pay attention to the fetal heart rate, too fast, too slow or irregular all suggest that there may be abnormalities in the fetus in the womb, usually related to the state of the pregnant woman and fetal hypoxia in the womb. If the result is unsatisfactory when listening to the fetal heart sound for the first time, the pregnant woman can rest and stabilize for half an hour and then test again, and if there is no obvious abnormality, it can be rechecked regularly; if there is any abnormality, it is necessary to consult the doctor for examination and evaluation of the risk, so as to guarantee the safety of the pregnant woman and the fetus.