Progesterone fall mainly occurs in pregnancy, consider the first sign of miscarriage, ectopic pregnancy, etc.; for women who are not pregnant, consider the luteal insufficiency caused. 1. Pre-eclampsia: low progesterone is a manifestation of embryonic dysplasia, with a small amount of vaginal bleeding accompanied by paroxysmal abdominal pain, the cause of which is related to a variety of factors such as the embryo and the mother. 2. Ectopic pregnancy: Ectopic pregnancy manifests as menopause, abdominal pain, vaginal bleeding, etc. The etiology of ectopic pregnancy is commonly associated with tubal lesions, and the examination will find that progesterone has dropped significantly. 3. Luteal insufficiency: Luteal insufficiency manifests as menstrual disorders, infertility or miscarriage, etc. The causes are related to follicular growth disorders and poor follicular development. There are many reasons for the drop of progesterone, so it is recommended to consult a doctor for a clear diagnosis.