Diagnosis of early pregnancy
The hCG value after pregnancy varies from person to person, and there is no clear normal value range. The blood hCG can be increased to more than 2500IU/L at 35-50 days of pregnancy. It peaks in 60-70 days. The urine hCG of multiple pregnancies was often higher than that of single pregnancy. In pregnancy induced by gonadotropin stimulation, it is also necessary to note that 10 times the half-life of exogenous hCG administration is passed before pregnancy can be confirmed.
Gestational age can be determined by analyzing the hCG of at least 2 blood samples before 7 weeks gestation. These 2 blood samples should be spaced 2-7 days apart, as hCG increases about every 2 days during pregnancy. The linear relationship between the logarithm of hCG concentration and the measured days can be obtained.