Cervical insufficiency

Cervical insufficiency refers to the pathological dilation and relaxation of the cervix due to a reduced amount of fibrous tissue, elastic fibers, and smooth muscle in the cervix, or a rupture of fibrous tissue in the internal cervical os, leading to a weakened sphincter function of the isthmus. This condition is common in individuals with a history of cervical surgery, or a history of recurrent miscarriage or preterm birth suspected to be caused by cervical insufficiency. The main symptom is recurrent miscarriages occurring at the same gestational age, without obvious signs of impending miscarriage, and the fetus is suddenly expelled intact.