The normal range of progesterone reference values during pregnancy is as follows: First, progesterone shows a gradual increase throughout pregnancy, and the range of progesterone reference values also increases gradually with the size of the pregnancy week. In the period of 7-13 weeks of pregnancy, the progesterone value is between 32.6-139.9 nmol/L, in the period of 14-37 weeks of pregnancy, the progesterone value is between 62.0-262.4 nmol/L, and in the period of 37-42 weeks of pregnancy, the progesterone value is between 206.7-728.2 nmol/L. Secondly, the content of progesterone is regulated by the hypothalamic-pituitary-gonadal axis and influenced by the nutritional status of the pregnant woman as well as her physique. If the physique is relatively good or the feedback function decreases, the content of progesterone will rise. Thirdly, the change of progesterone value is related to two aspects of liver and kidney, than if the liver inactivates more, it will also lead to the decrease of progesterone content in the body, it will be lower than the normal value.