Miscarriage on the fiftieth day of pregnancy may be caused by chromosomal abnormalities of the embryo, progesterone deficiency, exposure to harmful substances, and the mother’s own diseases. 1. Embryonic chromosome abnormality: the more common reason for miscarriage on the fiftieth day of pregnancy is embryonic chromosome abnormality, chromosome number and structural abnormality, embryonic dysplasia resulting in miscarriage of the fetus. 2. Insufficient progesterone: Insufficient progesterone in the body during the first fifty days of pregnancy will cause the fetus to miscarry if it does not support the pregnancy. 3. Exposure to harmful substances: During pregnancy, frequent exposure to radiation-based tests, such as X-rays and CTs, and a polluted environment may cause embryonic dysplasia and miscarriage. 4. Mother’s own disease: mother’s own disease, such as hypothyroidism, so that the cell oxidation process suffered obstacles, can also cause miscarriage. There are many reasons for miscarriage on the fiftieth day of pregnancy, and you can go to the hospital for examination and judgment.