Bleeding and dropping clots at thirteen weeks of pregnancy may be caused by pre-eclampsia, low placental state or certain cervical diseases. It is recommended to seek medical attention promptly and treat according to the cause. Common causes and treatments 1. Pre-eclampsia: The main symptom of pre-eclampsia is vaginal bleeding. We can measure the length of the cervical canal through ultrasound to help determine whether there is pre-eclampsia. If the cervical canal is short, it is judged that there is a possibility of pre-eclampsia miscarriage, and the patient needs to reduce activities, prohibit sexual life and avoid excessive mental tension. If the preterm abortion is caused by low progesterone level, it is often also possible to take oral or intramuscular progesterone for fetal preservation. Please combine the use of specific drugs with your own situation and under the guidance of a professional doctor. 2. Placental hypoplasia: When placental hypoplasia is present, painless recurrent vaginal bleeding often occurs. The treatment principle is absolute bed rest, suppression of contractions to stop bleeding, timely correction of anemia and prevention of infection, and depending on the gestational age, progress of the disease and severity of symptoms to see if the pregnancy needs to be terminated; 3, cervical diseases: such as cervical cancer, cervical polyps and other diseases may appear vaginal bleeding, and the cause should be clarified after detailed gynecological examination and then treated for the cause. If a pregnant woman has such abnormalities, she should try to avoid nervousness, and when the cause and treatment plan are not known, she should take normal nutrition according to the pregnancy plan, and pay attention to bed rest and ensure sleep time.