At 55 days of pregnancy, the normal range of progesterone in a pregnant woman’s body is approximately between 33-140 nmol/L. Each pregnant woman has a different physical condition and different ovarian function, and her body secretes different progesterone after pregnancy. Some people with good health and good ovarian function have higher progesterone secretion in their bodies. However, if the progesterone secretion is within the normal range, it will not affect the normal development of the fetus. If the progesterone secretion is insufficient, it will affect the development of the placenta, and if the placenta does not develop well, it will not be able to provide sufficient nutrients for the fetus to grow and develop, and then it will be stunted, and in serious cases, it may even cause the fetus to stop developing or miscarry. Therefore, if you have a low progesterone level, you need to cooperate with your doctor to use progesterone and other drugs to actively do fetal preservation treatment.