Bleeding in the second trimester of pregnancy can be caused by miscarriage and ectopic pregnancy. 1. Miscarriage: The termination of pregnancy before 28 weeks is called miscarriage, which is mainly manifested by vaginal bleeding and abdominal pain after menopause. The most common cause of early miscarriage is chromosomal abnormality of the embryo or fetus; the common cause of late miscarriage is genital abnormality or endocrine abnormality, and pregnant women suffering from systemic diseases may also lead to miscarriage. 2. Ectopic pregnancy: the fertilized ovum is called ectopic pregnancy when it is deposited outside the uterine cavity. The main manifestations are menopause, abdominal pain and vaginal bleeding. The most common ectopic pregnancy is tubal pregnancy, and the main cause of tubal pregnancy is tubal inflammation. Clinically, if you find the symptoms of bleeding after more than two months of pregnancy, you should go to the hospital in time, follow the doctor’s instructions for treatment, and if necessary, terminate the pregnancy.