Bleeding after transplantation or in early pregnancy is a common occurrence, with approximately 20-30% of all pregnancy cycles experiencing early pregnancy bleeding. The sources of bleeding in early pregnancy are: 1. maternal conditions. 2. The embryo itself. 3. External stimulation. There are 6 major causes of bleeding in early pregnancy as follows: 1. Cervical lesions: For bleeding in early pregnancy, cervical problems are often overlooked. Severe inflammation of the cervix leading to erosion, or originally existing cervical polyps, hormonal changes after pregnancy can cause bleeding from ruptured capillaries on the surface of the cervix. The uterine exfoliation cytology should also be checked regularly during pregnancy. 2, ectopic pregnancy: the incidence is 1%, with a slightly higher rate in patients with a previous history of ectopic pregnancy. It is due to the location of embryo implantation not in the uterine cavity, mostly in the fallopian tubes, horn of the uterus, cervix and even ovaries. Due to the weakness of the muscular layer in the non-uterine location, early pregnancy may produce abnormal vaginal bleeding (often mistaken for menstruation) and even severe abdominal pain or shock or even death due to intra-abdominal hemorrhage. 3. Pre-eclampsia: The causes of pre-eclampsia include: the invasion of the placenta on the myometrium and blood vessels before the placenta is fully formed, and the rupture of blood vessels can also lead to bleeding. Insufficient progesterone in the body to support embryo survival will also lead to vaginal bleeding (but luteal support will be strengthened after in vitro, and luteal deficiency is less common). Poor embryo implantation position, such as too close to the cervical opening or fallopian tube opening can cause abnormal bleeding. In addition, overworking and bad mood of the mother can also lead to bleeding due to poor maternal-fetal dialogue. 4.Gravida: Gravida is a benign chorionic disease with an incidence of about 1(1 in 1000). This condition is rare, no fetus is seen in the uterus, only blister-like fetal masses like grape bunches, and vaginal bleeding occurs very early in pregnancy. 5, the fetus stopped developing: sperm, eggs and embryo any aspect of the problem, will lead to abnormal development of the embryo and embryonic abortion. The mother’s extreme emotional stress, bad mood, and exposure to toxic and harmful substances in early pregnancy are also causes of fetal arrest. 6. Placenta problems: Placenta position is too low, close to the intrauterine orifice or covering the intrauterine orifice, which can cause vaginal bleeding. This is because the cervix does not grow as large as the body of the uterus with the enlargement of the gestational sac resulting in misplaced bleeding.