Progesterone is a hormone in the pregnant woman’s body that supports pregnancy, and the smooth progress of early pregnancy depends on adequate progesterone production. In this case, progesterone values in the 2nd trimester fluctuate in the range of 20.7-36.5 ng/ml. If the progesterone value in the patient’s body falls below this range, there is a possibility of miscarriage. Depending on the patient’s clinical symptoms, oral progesterone supplementation therapy is required if necessary. However, it is important to emphasize that there are two clinical units of progesterone, which are tested in different procedures. Different hospitals may use different units of progesterone values. The progesterone values are also different for different progesterone units. Therefore, the normal range used varies from hospital to hospital. Therefore, when it is necessary to compare progesterone levels, patients should observe the progesterone units on the back of the lab test. If the progesterone units are consistent with the standard range units mentioned above, then the normal range mentioned above can be taken. If the progesterone units do not agree, then the above values need to be converted to the new units of data by a simple conversion and the assessment of the progesterone value levels will be done again. Therefore, it is necessary to keep an eye on the changes in progesterone values during pregnancy and if progesterone levels are lower than normal, progesterone supplementation therapy needs to be given.