Doing fetal heart ultrasound is relatively easy to succeed, even if the fetus is not in a good position, it is easy to pass the examination by changing the position by walking around and stroking the stomach. 22~28 weeks of pregnancy is an important period to do heart ultrasound, at this time the fetal heart development is formed, the amount of amniotic fluid in the uterus is more sufficient, the position of the fetus in the uterus is not fixed, it is easier to implement the heart ultrasound, and it is easy to pass if there is no abnormality. Do heart ultrasound when the fetal position is not good may not see clearly, you can eat some appropriate chocolate or snacks, touch the stomach, climb stairs, listen to music, will make the fetal position change, see the fetal heart is easy to succeed. The first time the heart ultrasound is unsuccessful, you can rest for a few days and then go back to the hospital to review the fetal heart ultrasound, to determine whether there is any developmental abnormality of the fetal heart. It is important to do a good maternity checkup during pregnancy so that any abnormalities can be dealt with in a timely manner.