Fetal heart buds usually appear as small seahorses on ultrasound, but the exact shape cannot be generalized due to the time of pregnancy. During the development of a fertilized egg in a woman, the first 8 weeks of the embryo is usually called the fetal heartbeat, which can be seen on ultrasound between the 42nd and 49th day of pregnancy, and usually takes the shape of a small seahorse on ultrasound. Fetal buds usually develop as the number of weeks of pregnancy increases. In the fourth week of pregnancy, the size of the fetal buds is usually around 0.2 cm, which cannot be seen by ultrasound, and in the seventh week of pregnancy, the fetal buds may be around 1.3 cm, and the heart tube can be seen to be pulsating. It is recommended that patients should closely observe their own physical condition and the state of the fetus in the womb during pregnancy, undergo regular obstetric examination, and go to the hospital in time if they feel unwell.