Progesterone is produced by the ovarian corpus luteum in early pregnancy and is an important hormone that supports the development of a fertilized egg. As the embryo develops to 8-10 weeks, the placental syncytiotrophoblasts secrete large quantities of chorionic gonadotropin (HCG), as well as progesterone, which replaces the function of the ovarian corpus luteum. Early progesterone levels are one of the indicators for assessing embryonic development. Progesterone is a hormone secreted by the ovarian corpus luteum of pregnancy. The role of progesterone is to maintain a smooth pregnancy. Therefore, the occurrence of miscarriage may occur when the level of progesterone in the body is low due to a number of factors. It is generally accepted that the normal value of progesterone in a 30 day pregnant woman is (18-25) ng/ml. it should be emphasized here that there is another unit of progesterone. If a different unit of progesterone is taken, then the normal value of progesterone is also different. Therefore, while assessing the progesterone level, one needs to pay attention to the unit behind the value. During pregnancy, if the progesterone value is found to be below the normal range, the pregnant woman needs to observe herself for symptoms such as lower abdominal pain and vaginal bleeding. If necessary, ultrasonography can be performed to find out whether the embryo is developing normally in the uterus. If the embryo develops well, there are no abnormal clinical symptoms, and there is no adverse pregnancy history, the observation can be continued. If there is a history of adverse pregnancy, such as a history of sterilizations, progesterone can be applied as appropriate for fertility preservation treatment, while monitoring the embryo development. This is because most of the causes of early miscarriage are due to the poor development of the embryo itself. Unless a history of miscarriage due to luteal dysplasia is confirmed, then progesterone should be applied for fertility preservation therapy. To summarize, the normal value of progesterone in 30 days of pregnancy is (18-25) ng/ml, if the value of progesterone is lower than the normal range, it is recommended to consult a doctor in time.