In early pregnancy, HCG increases rapidly, doubling time is about 1.4 to 2.2 days, that is, the usual clinical saying “doubling every other day”. Normal pregnancy in early pregnancy, there are individual differences, blood HCG daily growth of at least about 24%, 2-day growth of 53%, such as HCG growth is slow, should be considered whether there is ectopic pregnancy, preeclampsia and other abnormalities. Blood HCG is not always elevated during pregnancy. Generally, HCG reaches its peak at 8 to 10 weeks of pregnancy, which can be as high as 100,000 to 200,000 IU/L, and then decreases rapidly after 1 to 2 weeks, and then decreases to the lowest level at about 20 weeks of pregnancy until delivery. If the clinical examination finds that the blood HCG is not well doubled, high or low, etc., it is recommended to consult the doctor in time to avoid delaying the best time for diagnosis and treatment.