The bleeding phenomenon during oral progesterone is related to the omission of progesterone, because progesterone is a progestin, which should not be omitted during oral administration, and the omission will interrupt the continuous level of progesterone, which will cause progesterone withdrawal and abnormal performance. There will also be some women who take progesterone orally during the period for the role of fetal preservation, indicating that the progesterone has not reached sufficient levels, which will still cause abnormal bleeding. It is necessary to increase the dose of oral progesterone and play the purpose of stopping bleeding and stabilizing the fetus, or continue to take it orally, and as the dose of progesterone reaches a certain peak value over time, it will play the role of stopping bleeding and preserving the fetus. Also related to adverse drug reactions, because progesterone in the oral period of a small number of women will appear retreat bleeding, this situation does not need to stop the drug, continue to take the drug orally, generally within 3-5 days after the oral to achieve the purpose of hemostasis.