Low progesterone can be treated with progesterone. If progesterone is low, it may shorten the menstrual cycle significantly in the non-pregnant state, often with a menstrual cycle of less than 25 days, or irregular vaginal bleeding in the second half of the menstrual period. It is recommended to supplement progesterone after ovulation, which will improve the corresponding clinical symptoms such as shortened menstrual cycle due to low progesterone. If low progesterone occurs during pregnancy, there is a risk of pre-eclampsia or even miscarriage. Therefore, once low progesterone is detected during pregnancy, bed rest must be given and progesterone should be given orally or intramuscularly in order to inhibit the contraction of the smooth muscle of the uterus and to allow the pregnancy to continue.