Fetal heart in 15 weeks of pregnancy is usually in the position of 1-2 horizontal fingers above the pubic bone, but the position of the fetal heart will change with the growth and development of the fetus, and the position is usually not fixed. When listening to the fetal heart at 15 weeks, the uterine fundus is below the umbilicus and the umbilicus, and the fetal heart can be heard 1-2 horizontal fingers above the pubic bone, and the sound of the fetal heart is clearer in this position, and it can be heard as a double tone, similar to the ticking sound of a clock. However, the position of the fetal heart and fetal position has a certain relationship, different fetal position fetal heart position will change, not fixed. Therefore, when monitoring the fetal heart, it is not only necessary to judge according to the week of pregnancy, but also according to the position of the uterine fundus and fetal orientation to help find the specific location of the fetal heart.