After pregnancy, if there are two reasons for low progesterone, one reason is that the quality of the corpus luteum of pregnancy is not good and the progesterone secreted is not enough, in this case, progesterone can be applied to protect the fetus, and the effect of using progesterone to protect the fetus is still relatively good. Another reason is that the fetus itself is not developing normally and cannot effectively stimulate the corpus luteum to produce progesterone, and the effect of progesterone in this case is also not good. If the embryo itself is not developing well and there is a spontaneous abortion, it is also a natural elimination method. If a spontaneous miscarriage occurs and the effect of conventional fertility preservation treatment is not good, it will develop into a refractory miscarriage, which may be caused by abnormal fetal development and should be treated with timely uterine clearance to avoid causing infection in the uterine cavity.