At 42 days of pregnancy i.e. 6 weeks of gestation, the fetal buds can be seen in the uterine cavity under ultrasound examination and the fetal heart can be seen at 50-60 days. The fetal heartbeat and fetal bud are the results seen under ultrasound examination. Generally, the embryonic sac in the uterine cavity can be seen under ultrasound examination around 30-40 days after pregnancy, the embryonic bud in the uterine cavity can be seen at 40-50 days after pregnancy, and the fetal heartbeat, embryonic bud and primitive heart tube beat can be seen at 50-60 days after pregnancy. However, the time to see the fetal heart and germ may vary from one pregnant woman to another. Some pregnant women have irregular periods and the appearance of the germ may be earlier or later accordingly. Therefore, it is recommended that pregnant women should undergo ultrasound examination at the prescribed time to confirm pregnancy and rule out ectopic pregnancy, estimate the gestational week and detect serious fetal abnormalities in early pregnancy, and to detect fetal development and rule out abnormalities in middle and late pregnancy.