Women with low progesterone usually need to keep the fetus until 3 months, when the fetus is stable and progesterone can be stopped. The first 3 months of pregnancy is an important period for fetal development. When a little vaginal bleeding occurs, active fetal preservation treatment is needed and patients are generally advised to keep the fetus until 3 months. The placenta itself can secrete progesterone, which also has a therapeutic effect on fetal preservation, and the fetal organs are basically formed, so the chance of miscarriage is obviously reduced, and there is no need for exogenous progesterone supplementation. The specific duration of fetal preservation should be determined according to the condition of the pregnant woman and the fetus, and cannot be generalized. During pregnancy, pregnant women with low progesterone should pay attention to bed rest, avoid walking around as much as possible, and avoid eating spicy and stimulating food. At the same time, pay attention to the regularity of life, ensure balanced nutrition, and have regular prenatal checkups.