Bleeding in a new pregnancy may be caused by implantation bleeding, preeclampsia, ectopic pregnancy, uterine diseases and so on. 1. Bleeding on implantation: Since the embryo will implant in the uterus after the first pregnancy, and the implantation site is rich in capillaries, there may be a mild damage to the endometrium, causing a small amount of bleeding. 2. Pre-eclampsia: Pre-eclampsia is caused by poor embryonic development, infection, anemia, etc. It usually manifests itself as a small amount of vaginal bleeding, which may be accompanied by abdominal pain. 3. Ectopic pregnancy: Ectopic pregnancy occurs when the fallopian tube fails to transport the fertilized egg back to the uterus due to adhesion or impassability, which may cause the fertilized egg to settle in the fallopian tube. The narrow lumen of the fallopian tube and the gradual growth of the embryo may lead to the rupture of ectopic pregnancy and bleeding. 4. Uterine diseases: If you suffer from uterine fibroids, congenital uterine anomalies, endometriosis and other diseases, you may experience bleeding in a new pregnancy. When bleeding from a new pregnancy occurs, you should go to the hospital in time and ask the doctor for a clear diagnosis and treatment.