Progesterone is a type of progesterone. The progesterone value in the mother’s blood gradually increases to a certain level with the number of weeks of pregnancy and plays an important role in the changes in the endometrium, myometrium and mammary glands with the synergistic effect of estrogen. If progesterone is too low, there is a risk of not being able to continue to maintain the pregnancy. Low progesterone is usually caused by luteal insufficiency in women, which is produced by the ovarian corpus luteum in early pregnancy, and low progesterone is secreted by insufficient luteal function; also if the uterus develops abnormally, the embryo cannot grow normally, which can also lower progesterone. In normal pregnancy, increased progesterone can prevent the embryo from being rejected by the mother, thus maintaining a normal pregnancy. If progesterone is insufficient, the embryo is easily rejected by the mother and causes miscarriage. The amount of progesterone is directly related to whether the pregnancy can proceed normally, but whether the embryo can develop normally is not determined by progesterone. When the embryo is developing normally and the progesterone is not enough, the progesterone supplementation is mostly used clinically by intramuscular injection or oral progesterone medication to assist the normal development of the fetus. The amount of progesterone supplementation is different for each individual. It is recommended that patients with low progesterone should visit a regular hospital, and the specific supplementation and dosage should be determined under the guidance of the doctor according to the patient’s own situation.