The causes of early pregnancy bleeding are: 1, miscarriage Most of them occur due to fetal chromosomal abnormalities, maternal hormonal disorders, congenital abnormalities or defects of the uterus, immune system problems, reproductive tract infections, chronic diseases of pregnant women (such as heart disease, kidney disease and blood disorders), overwork, stress, too violent sex, external impact, environmental pollution, improper use of drugs, smoking, drinking, excessive intake of Caffeine or other foods that promote the contraction of the uterus, etc. Before the placenta is fully formed, the embryo is not stable and therefore many factors can cause miscarriage. When miscarriage occurs, the embryo will be separated from the uterine wall to varying degrees, and once the blood vessels on the separated surface rupture, it will cause vaginal bleeding symptoms. 2, cervical lesions Mostly occur in complicated sexual life, poor hygiene habits, abnormal living habits and poor body resistance. For early pregnancy bleeding, many people tend to ignore the problem of cervix. Severe inflammation of the cervix leading to erosion or pre-existing cervical polyps can easily cause bleeding from ruptured surface capillaries due to hormonal changes after pregnancy. In recent years, the most common age group for cervical cancer has quietly decreased to 30-40 years old. Being pregnant does not necessarily mean that there is no problem with the cervix, and regular pap smears should be done before and after pregnancy. 3. Ectopic pregnancy mostly occurs when there is a history of pelvic inflammation, pelvic adhesions or tubal surgery or ectopic pregnancy in the previous pregnancy. When the fertilized egg lays outside the uterus, it is called ectopic pregnancy, mostly in the fallopian tube. The wall of the fallopian tube is so thin that it cannot provide enough nutrients to the embryo, and the gradually developing fertilized egg swells the wall of the fallopian tube, leading to rupture of the wall and abnormal vaginal bleeding at 7 to 8 weeks of pregnancy, or even severe abdominal pain or shock due to massive intra-abdominal bleeding. The cause of staphylococcal fetus is not known, but it occurs when the mother is younger than 20 years old or older than 40 years old, lack of carotene and animal fat in food, history of miscarriage, history of staphylococcal fetus, smoking, etc. Staphylocytosis is a benign chorionic disease. It is called “gravida” because of the abnormal proliferation of trophoblast cells in the placental villi and the transformation of the terminal villi into blisters, which are connected in bunches and resemble grapes. In the early stages of pregnancy, symptoms such as abnormal vaginal bleeding, severe vomiting and even heart palpitations may occur.