The most common cause of vaginal bleeding during early pregnancy is: miscarriage. Miscarriage usually starts with a small amount of vaginal bleeding, often a dark red or coffee-colored discharge, sometimes accompanied by vague pain in the lower abdomen, which is considered a preterm miscarriage. After treatment by the doctor and rest, in most cases the symptoms disappear and the pregnancy can continue. However, if the symptoms worsen, bleeding increases, lower abdominal pain becomes apparent, or even fleshy tissue is discharged from the vagina, then miscarriage is inevitable and is considered a refractory miscarriage. If the pregnancy is completely expelled, the bleeding will gradually decrease, and the abdominal pain will be relieved, the abortion is complete and usually does not require special treatment. If the pregnancy is not completely expelled, the bleeding is still heavy and the abdominal pain is obvious, the abortion is mostly incomplete and in most cases emergency evacuation is needed. The most dangerous cause of vaginal bleeding during early pregnancy is: ectopic pregnancy, also known as ectopic pregnancy. As the name suggests, it means that the fertilized egg does not settle in the endometrium, but in a tissue outside the endometrium. 95% of ectopic pregnancies occur in the fallopian tubes. The reason why ectopic pregnancy is dangerous is that as the embryo develops, the fallopian tube cannot support the growing embryo and the chorion penetrates the wall of the tube, causing it to rupture, resulting in massive bleeding inside the stomach, which can cause shock or even death, while the amount of vaginal bleeding at this time is still not significant. Women should be even more alert if they have a history of pelvic infection, have undergone hysterectomy, or have had tubal surgery. Another more dangerous cause is: gravidity. Most patients with gravida have intermittent small amounts of bleeding, but this may be interspersed with repeated heavy bleeding several times, sometimes with blister-like material found in the blood. More severe cases can cause severe pregnancy vomiting and hypertensive disorders of pregnancy (proteinuria, hypertension, edema). The treatment is mainly a curettage, but it is worth noting that there is a risk of malignant transformation of the gravida into invasive gravida, so the mother-to-be must insist on regular review. In addition, some gynecological problems can also cause vaginal bleeding during early pregnancy, such as cervical erosion and cervical polyps. These diseases can usually be detected under careful examination by a specialist. However, bleeding caused by cervical lesions is often difficult to distinguish from bleeding caused by miscarriage, and then early pregnancy doctors often treat them according to miscarriage first, otherwise they may cause unavoidable losses. If the cervical polyp is large, a minor surgery to remove the polyp can be considered at mid-trimester to avoid continued confusion.