Uterine blood accumulation in early pregnancy is mainly considered to be related to preeclampsia, abnormal embryonic development, ectopic pregnancy and so on. 1. Pre-eclampsia: If the abdomen is stimulated by external force in early pregnancy or inappropriate sexual life may cause the capillaries of the embryo or placental villi to rupture, causing bleeding and further causing blood accumulation in the uterine cavity, and if more and more blood accumulates in the uterine cavity, there may be the possibility of pre-eclampsia. 2. Abnormal placental development: If the hormone secretion function of the ovary of the pregnant woman decreases, it may cause the embryo to be underdeveloped, which further causes a small amount of bleeding in the endometrium, resulting in blood accumulation in the uterine cavity. 3. Ectopic pregnancy: If there is blood accumulation in the uterus and there is no obvious gestational sac in the uterine cavity, you need to be highly cautious of ectopic pregnancy. If ectopic pregnancy occurs and the level of human chorionic gonadotropin in the body of the pregnant woman grows unsatisfactorily, it may cause partial exfoliation of the endometrium, which leads to hemorrhage in the uterine cavity. The occurrence of uterine blood in early pregnancy is not limited to the above mentioned diseases. Pregnant women are advised to go to the hospital in time, complete the relevant ultrasound examination, make a clear diagnosis and then actively treat the cause to avoid adverse effects.