After pregnancy, HCG will gradually increase and reach the highest level at around 10 weeks of pregnancy, and then slightly decrease and start to stabilize at a higher level without further increase. When biochemical pregnancy occurs, HCG will be under 200 IU/L and will not rise too much. In intrauterine pregnancy, HCG will increase with the growth of pregnancy week during early pregnancy and will double every other day, reaching up to about 100,000 IU/L. HCG is a relatively early indicator for diagnosing early pregnancy, which should be combined with progesterone level and gynecological ultrasound examination, the size of the gestational sac in the uterine cavity and the early and late appearance of the fetal germ and fetal heart to predict the early embryonic growth and development.