What is threatened abortion? Threatened abortion refers to a series of adverse symptoms experienced by pregnant women in the early stages of pregnancy, such as backache, abdominal pain, vaginal bleeding, etc. These symptoms may cause abnormal embryonic development and eventually lead to embryonic death or miscarriage. Threatened miscarriage is the most common cause of miscarriage in the first three months of pregnancy, and it is important for women trying to become pregnant to understand the symptoms and prevention of threatened miscarriage. Symptoms of threatened abortion 1. Vaginal bleeding: Vaginal bleeding in early pregnancy may be caused by problems with embryonic development, or it may be one of the symptoms of threatened abortion. 2. Backache and back pain: a precursor