Progesterone, or progesterone, also known as progesterone or progesterone, is a natural progesterone that can play a role in protecting the endometrium of the female uterus and is important for the normal fertilization of the egg. In addition, if progesterone is low after pregnancy, it is easy to cause the fertilized egg to fail to develop normally, and in serious cases, it can lead to miscarriage. The specific roles of progesterone are as follows: 1, help embryo bed: women in ovulation, the corpus luteum secretion of progesterone can promote the growth of the mucosal glands of the uterus, ready for the fertilized egg to bed, and after the embryo bed, it makes it produce the placenta, and reduce the excitability of the uterus, so that the fetus can grow safely; 2, inhibit uterine contractions: progesterone can inhibit uterine contractions, but does not affect the normal development of the fetus, can allow the pregnancy to continue. Progesterone can also protect the fetus. Progesterone can change the permeability of the myometrial cell membrane to ions of pregnant women, thus reducing the degree of uterine response to various stimuli, thus presenting the role of fetus protection; 3. Immune protection: progesterone is at normal value, which helps improve the immune function of pregnant women. During pregnancy, the amount of progesterone secretion will increase, which can protect the fetus from maternal rejection and thus maintain a normal pregnancy. However, if the amount of progesterone secreted by pregnant women is too low, it will easily lead to fetal miscarriage.