The precursors of miscarriage usually include irregular vaginal bleeding, abdominal pain, and abnormal ultrasound or blood tests, etc. If such abnormalities occur, you should be alert to the occurrence of miscarriage and seek timely medical treatment for fetal preservation. Common symptoms: 1. Irregular vaginal bleeding: the amount of blood is generally small, dark red or dark brown, and the bleeding symptoms will be more obvious after activity or overexertion; 2. abdominal pain: along with uterine contractions, there will be continuous lower abdominal pain, similar to the performance of dysmenorrhea, and the pain level will gradually increase as the condition worsens; 3. 3, check abnormalities: pregnant women with aura of miscarriage will find some abnormalities when doing ultrasound or blood test, such as liquid dark area in the uterine cavity found by ultrasound, low value of progesterone in blood test, etc. Treatment: If the amount of bleeding is not too much and the ultrasound examination shows that the fetus is developing well, you can apply drugs such as dydrogesterone and progesterone for fetal preservation treatment under the guidance of the doctor. If the embryo is poorly developed or has stopped developing, the pregnancy should be terminated if necessary. Precautions: Pregnant women with a tendency of pre-eclampsia need to reduce their activities, pay attention to ensure sufficient rest and strictly prohibit sexual life. Take appropriate supplements of folic acid and vitamin E in early pregnancy, and keep a relaxed and happy mood to avoid excessive psychological stress.