Bleeding from a shortened cervix in mid-pregnancy can be caused by contractions and cervical insufficiency, among other things. During frequent contractions, the cervix shortens and dilates, the membranes separate from the cervix and vaginal bleeding occurs as a symptom of miscarriage. A few women with a short cervical canal and cervical insufficiency are usually prone to miscarriage in the middle of pregnancy, when vaginal bleeding occurs. When a pregnant woman experiences abnormal vaginal bleeding, she must not be careless and needs to go to the hospital as soon as possible to get medical attention and test the condition of the fetal heartbeat to determine whether the fetus is normal in the uterus. If the fetus is in good condition, active fertility preservation treatment is needed, and patients with cervical insufficiency need to undergo cervical cerclage.