The possible causes of normal abortion in pregnancy pregnancy test include chromosomal abnormalities, maternal factors, placental factors, umbilical cord factors, paternal factors and environmental factors. 1. Chromosomal abnormalities: chromosomal abnormalities include numerical abnormalities and structural abnormalities, with chromosomal numerical abnormalities being the most common. 2. Maternal factors: (1) Abnormalities of reproductive organs: for example, the mother suffers from uterine fibroids, which can cause fetal blood supply to decrease and cause fetal arrest. (2) Systemic diseases: hypertensive syndrome of pregnancy, cardiovascular disease and other small arterial spasms throughout the body, the embryo blood supply abnormalities leading to fetal arrest. (3) Bad habits and strong stress: surgery, abdominal impact, excessive smoking, alcoholism, drug abuse, etc., can lead to fetal arrest. (4) Endocrine abnormalities: female luteal insufficiency and other endocrine abnormalities lead to fetal arrest. (5) Infections: Intrauterine infections, especially in early pregnancy, can lead to fetal arrest. (6) Abnormal immune function: the embryo belongs to allogeneic transplantation, and the immune maladaptation between mother and fetus can cause the rejection of the fetus by the mother. (3) Placental factors: Verticollis, placental abruption, etc., which reduces the nutrient and blood supply to the fetus, can lead to fetal arrest. 4. Umbilical cord factor: Umbilical cord torsion, knotting, neck wrapping, etc. can cause abnormal blood supply to the fetus, resulting in fetal arrest. 5. Father’s factor: Decrease in the quality of father’s sperm is one of the reasons for the embryo to stop developing. 6. Environmental factors: Excessive exposure to radiation, such as X-rays, and excessive exposure to chemicals, such as benzene, can lead to fetal arrest. Women who have miscarriage after pregnancy should go to the hospital for a systematic examination to clarify the cause and standardize the treatment according to the cause.