The conversion relationship between HCG major and minor units is major unit x 3.8 equals minor unit. HCG (Human Chorionic Gonadotropin) is a glycoprotein hormone, which can be used to understand the development of the embryo by monitoring the rise and doubling of blood HCG after pregnancy. In clinical practice, the measured value of HCG can be divided into large units (IU/L) and small units (mIU/ml), and the conversion relationship between them is IU/L x 3.8 = mIU/ml, which can be converted under the guidance of the doctor. In normal pregnancy, HCG starts to be secreted about 1 day after the fertilized egg is laid, and when the blood HCG value is >25IU/L, it indicates a positive pregnancy result, and then it will rise by 1 times every 1.7~2 days, and the value will reach the peak at 8~10 weeks of pregnancy, and then it will decline rapidly. When the blood HCG doubling is unsatisfactory in early pregnancy, there may be the possibility of embryonic dysplasia, which needs to be actively treated under the guidance of the doctor.