The occurrence of black blood sludge in early pregnancy may be related to factors such as implantation bleeding, preeclampsia and ectopic pregnancy. 1. Bleeding on implantation: in early pregnancy, due to the fertilized egg implantation stimulation of the uterine wall, may produce a small amount of bleeding, due to the amount of bleeding is relatively small, in the uterine cavity or vagina to stay, there may be a black blood scum situation. 2. Pre-eclampsia: The development of embryo in early pregnancy is not stable, when there is embryonic arrest, or by the outside world, hormone levels and other aspects of the influence, it is easy to have pre-eclampsia, and then the symptoms of vaginal bleeding, some patients may also be accompanied by paroxysmal pain in the lower abdomen and other symptoms. 3. Ectopic pregnancy: Ectopic pregnancy refers to the fertilization of the egg in the uterus outside the body cavity of the bed, the patient may appear abdominal pain, vaginal bleeding and other symptoms, pregnant women in the early stages of pregnancy flow black blood slag may be caused by ectopic pregnancy. In addition, the low position of the placenta, cervical lesions, inflammation of the cervix may also cause such a situation, it is recommended that the patient consult a doctor for examination in a timely manner, to clarify the cause of the disease and then carry out targeted treatment.