The reference range of HCG values for pregnant women at 6 weeks of pregnancy is 4000-100000 IU/L. Clinically, HCG combined with progesterone values are usually used to jointly determine the development of the early embryo. If the HCG value is doubled every other day at 6 weeks of pregnancy and the progesterone is within the normal range, the intrauterine fetal heart and fetal bud can be detected by ultrasound, which indicates that the fetus is developing well and can be diagnosed as intrauterine pregnancy. If HCG is lower than normal, it may be related to embryonic dysplasia or ectopic pregnancy. The diagnosis can be confirmed by ultrasound examination combined with HCG values. If, on ultrasound, no gestational sac is found in the uterus, the HCG value is low and a gestational sac is found outside the uterus, an ectopic pregnancy is diagnosed and, if necessary, requires surgical treatment to clear the uterus. If the pregnancy is diagnosed as intrauterine and the fetus is found to have a pulsating heart tube under ultrasound, it may be due to embryonic dysplasia and the progesterone and estradiol values should be combined to determine the development of the embryo. If the HCG value is too high, it may be caused by twin or multiple pregnancy, but it may also be due to gravidity. Ultrasound is recommended to find out the condition of the fetus in utero and to check whether it is a multiple or singleton pregnancy, or a gravidity. If it is a gravida, it should be treated as soon as possible to avoid abnormal enlargement of the uterus, which may cause harm to the body.