Does the fetal heart test affect the fetus? Fetal heartbeat, as the name implies, is the heartbeat of the fetus, reflecting the state of the fetus in utero, and it is sensitive to changes when various causes cause fetal hypoxia. The normal fetal heart rate is 110 to 160 beats per minute. The fetal heartbeat is just like the human heartbeat, it is necessary to exist, otherwise it is stillborn. The fetal heartbeat should be listened to frequently during pregnancy checkups or hospitalization. Many pregnant women worry about the effect of fetal heartbeat testing on the fetus, and this article focuses on this issue. The way to detect the fetal heart: 1, ultrasound auscultation fetal heart, through Doppler auscultation when doing ultrasound. 2, fetal heart auscultator, this is the most common for ordinary pregnant women 3, fetal heart monitoring, using a fetal heart monitor to continuously listen to the fetal heart, most commonly used in late pregnancy and delivery. The above three methods, although different names, but the principle is to use the Doppler effect to listen to the fetal heart. Doppler fetal heart rate monitor (including ultrasound machine, stethoscope and fetal heart monitor) adopts the principle of non-focused continuous wave Doppler, which consists of an ultrasound transducer coupled to the maternal abdomen and an electrical circuit, and can monitor and record the fetal heart rate, mainly used for maternal monitoring of the fetus during late pregnancy, prenatal and delivery. The principle is that the ultrasound beam generated by the ultrasound transducer is aimed directly at the fetus, and part of the incident beam reaches the surface of the fetal heart movement, and the ultrasound frequency is frequency shifted due to the Doppler effect, which is detected by the receiving transducer, and the low frequency signal related to the fetal heart can be separated and amplified by signal processing for fetal heart detection. This principle of Doppler is to detect the fetal heart through ultrasound, unlike radiation (X-rays, CT, etc.), which is not harmful to human body. Current research has shown that all three of these fetal heart monitoring methods do not affect the fetus and are safe. But there are several instructions: 1, there is no need to buy their own fetal heart stethoscope 2, there is no need to excessive fetal heart stop, not because of fear of repeatedly listening to the fetal heart 3, whether to listen to the fetal heart and listening to the number of times is based on the needs of the condition, if normal pregnant women, each maternity check-up listening to the diagnosis can be, high-risk pregnant women (hypertension, premature rupture of membranes patients, etc.), need to detect the fetal heart 2-3 times a day is not too much. 3 times a day is not too much.